Structure determination of three furan-substituted benzimidazoles and calculation of π–π and C—H...π inter­action energies

The synthesis and structural characterization of 2-(furan-2-yl)-1-(furan-2-ylmeth­yl)-1H-benzimidazole [C₁₆H₁₂N₂O₂, (I)], 2-(furan-2-yl)-1-(furan-2-ylmeth­yl)-1H-benzimidazol-3-ium chloride monohydrate [C₁₆H₁₃N₂O₂⁺·Cl⁻·H₂O, (II)] and the hydro­bromide salt 5,6-dimethyl-2-(furan-2-yl)-1-(furan-2-ylmeth­yl)-1H-benzimidazol-3-ium bromide [C₁₈H₁₇N₂O₂⁺·Br⁻, (III)] are described. Benzimidazole (I) displays two sets of aromatic inter­actions, each of which involves pairs of mol­ecules in a head-to-tail arrangement. The first, denoted set (Ia), exhibits both inter­molecular C—H...π inter­actions between the 2-(furan-2-yl) (abbreviated as Fn) and 1-(furan-2-ylmeth­yl) (abbreviated as MeFn) substituents, and π–π inter­actions involving the Fn substituents between inversion-center-related mol­ecules. The second, denoted set (Ib), involves π–π inter­actions involving both the benzene ring (Bz) and the imidazole ring (Im) of benzimidazole. Hydrated salt (II) exhibits N—H...OH₂...Cl hydrogen bonding that results in chains of mol­ecules parallel to the a axis. There is also a head-to-head aromatic stacking of the protonated benzimidazole cations in which the Bz and Im rings of one mol­ecule inter­act with the Im and Fn rings of adjacent mol­ecules in the chain. Salt (III) displays N—H...Br hydrogen bonding and π–π inter­actions involving inversion-center-related benzimidazole rings in a head-to-tail arrangement. In all of the π–π inter­actions observed, the inter­acting moieties are shifted with respect to each other along the major mol­ecular axis. Basis set superposition energy-corrected (counterpoise method) inter­action energies were calculated for each inter­action [DFT, M06-2X/6-31+G(d)] employing atomic coordinates obtained in the crystallographic analyses for heavy atoms and optimized H-atom coordinates. The calculated inter­action energies are −43.0, −39.8, −48.5, and −55.0 kJ mol⁻¹ for (Ia), (Ib), (II), and (III), respectively. For (Ia), the analysis was used to partition the inter­action energies into the C—H...π and π–π components, which are 9.4 and 24.1 kJ mol⁻¹, respectively. Energy-minimized structures were used to determine the optimal inter­planar spacing, the slip distance along the major mol­ecular axis, and the slip distance along the minor mol­ecular axis for 2-(furan-2-yl)-1H-benz­imidazole.

S1. Introduction

Benzimidazole derivatives have a myriad of pharmacological uses, including as inhibitors of serotonin-activated neurotransmission (López-Rodríguez et al., 1999) and anti­viral agents (Varala et al., 2007). They are also used in anti­arrhythmic, anti­histamine, anti­ulcer, anti­cancer, fungicidal, and anthelmintical drugs (Horton et al., 2003). The benzimidazole rings and/or their substitutents have a propensity to inter­calate in DNA (Perin et al., 2014) and to form π-aromatic inter­actions with protein residues. For example, inter­actions with a phenyl­alanine residue accompany binding of benzimidazolone inhibitors in the active site of the BRPF1 bromo­domain (Demont et al., 2014). π–π and C—H···π inter­actions play a role in the binding of benzimidazole-based hepatitus C virus inhibitors (Patel et al., 2008); anti­anxiety drugs (Hayashi et al., 2009); multi-target EGFR, VEGFR-2 and PDGFR kinase inhibitors (Li et al., 2011); and serotonin receptor antagonists (de la Fuente et al., 2010). Furan-substituted benzimidazole derivatives are of particular inter­est. The 2-furan substituent binds in a deep hydro­phobic pocket of hepatitis C virus NS5B polymerase, leading to greater activity than the corresponding pyridyl derivative (Patel et al., 2008). 2-(Furan-2-yl)-1H-benzimidazole (trade name fuberidazole) is a potent fungicide (Matolcsy et al., 1989; MacBean, 2013). Furan and thio­phene also exhibit DNA inter­calating abilities (Trent et al., 1996; Chai et al., 2014; Mallena et al., 2004; Laughton et al., 1996).

In addition to their biochemical importance, benzimidazoles have been studied because of their potential use as proton-transfer agents in polymeric electrolyte membranes (Pangon et al., 2011; Chirachanchai et al., 2011), proton-conducting solids (Rachocki et al., 2014), and in crystal engineering water-free proton-transfer systems (Totsatitpaisan et al., 2008). Of particular inter­est is the structural reorganization that occurs upon protonation (Munch et al., 2001). Benzimidazole itself crystallizes in two forms, each exhibiting N—H···N hydrogen-bonded chains. However, the more thermodynamically stable α form (orthorhombic, Pna2₁) exhibits C—H···π inter­actions with an H···benzene-centroid distance of 2.64 Å (Dik-Edixhoven et al., 1973; Escande & Galigné, 1974; Stibrany et al., 2001), whereas the β form (orthorhombic, Pccn) exhibits π–π stacking with an inter­planar distance of 3.418 (8) Å (Krawczyk & Gdaniec, 2005). An examination of reported solid-state structures of 2-substituted and 1,2-disubstituted benzimidazoles reveals that both C—H···π and π–π aromatic inter­actions are common (for examples, see: Geiger et al., 2014; Geiger & Isaac, 2014; El Ghozlani et al., 2014; Yeong et al., 2013; Fathima et al., 2013; Krishnamurthy et al., 2013).

Although C—H···π and π–π aromatic inter­actions play an important role in biochemical systems (McGaughey et al., 1998) and in organic reactions (Nishio, 2005) and these inter­actions are especially common for benzimidazole and furan substrates, there is little in the literature regarding the optimal benzimidazole and/or furan geometries of the inter­acting moeties or the strengths of the inter­actions. We report herein the structures of 2-(furan-2-yl)-1-[(furan-2-yl)methyl]-1H-benzimidazole, (I), its hydro­chloride monohydrate salt, 2-(furan-2-yl)-1-[(furan-2-yl)methyl]-1H-benzimidazol-3-ium chloride monohydrate, (II), and the hydro­bromide salt 5,6-di­methyl-2-(furan-2-yl)-1-(furan-2-yl­methyl)-1H-benzimidazol-3-ium bromide, (III). In addition to complementing the previously reported structural studies on 1,3-difurfurylbenzimidizolium chloride monohydrate (Akkurt et al., 2009) and 2-(furan-2-yl)-1,3-bis­(furan-2-yl­methyl)-1H-benzimidazol-3-ium chloride monohydrate (Geiger et al., 2012), they provide an opportunity for exploring the preferred 2-furan-substituted benzimidazole stacking and C—H···π(furan) inter­actions. Toward that end, we have calculated inter­action energies using density functional (DFT) theory. Our results are compared to those reported for other aromatic systems (Sherrill et al., 2009; Ran & Wong, 2006; Grimme, 2008; Takahashi et al., 2010; Sánchez-García & Jansen, 2012).

S2. Experimental

S2.1. Synthesis and crystallization

S2.1.1. Preparation of 2-(furan-2-yl)-1-(furan-2-yl­methyl)-1H-benzimidazole, (I), and the hydro­chloride monohydrate salt, (II)

A solution of o-phenyl­enedi­amine (0.5000 g, 4.6 mmol) and 2-furaldehyde (0.84 ml) in ethanol (50 ml) was stirred for 2 h at room temperature. The solvent was removed by rotary evaporation and the product was isolated by silica-gel column chromatography (ethyl acetate–hexane, 1:2 v/v) (yield 80%). ¹H NMR (CDCl₃, 400 MHz): δ 8.62 (1H, d), 8.03 (1H, d), 7.82 (1H, d), 7.71 (1H, m), 7.50 (2H, m), 7.34 (1H, d), 6.78 (1H, d), 6.46 (1H, d), 6.32 (1H, m), 5.88 (2H, s). ¹³C NMR (CDCl₃): δ 149.2, 146.9, 144.0, 137.4, 132.6, 130.6, 127.3, 126.4, 119.8, 113.6, 113.4, 112.8, 110.5, 46.5.

Single crystals of (I) suitable for X-ray analysis were obtained by slow diffusion of hexane into an ethanol solution. Single crystals of (II) were obtained in the same way, except a few drops of concentrated HCl were added to the ethanol solution.

S2.1.2. Preparation of the hydro­bromide salt of 2-(furan-2-yl)-1-(furan-2-yl­methyl)-5,6-di­methyl-1H-benzimidazol-3-ium bromide

A solution of 4,5-di­methyl-1,2-phenyl­enedi­amine (0.5440 g, 4.0 mmol) and 2-furaldehyde (0.67 ml) in ethanol (30 ml) was stirred at room temperature under nitro­gen for 24 h. The solvent was removed and the product was purified by silica-gel column chromatography (ethyl acetate–hexane, 1:2 v/v). ¹H NMR (CDCl₃, 400 MHz): δ 7.62 (1H, d), 7.54 (1H, s), 7.33 (1H, d), 7.29 (1H, s), 7.14 (1H, d), 6.58 (1H, m), 6.28 (1H, d), 6.20 (1H, m), 5.59 (2H, s), 2.36 (3H, s), 2.40 (3H, s). ¹³C NMR (CDCl₃): δ 150.0, 145.8, 143.6, 143.0, 142.5, 141.8, 134.0, 132.2, 131.8, 120.0, 112.0, 111.8, 110.3, 110.0, 108.0, 41.8, 20.4, 20.0.

Single crystals of (III) suitable for X-ray analysis were obtained by slow diffusion of hexane into an ethanol solution containing a few drops of concentrated HBr.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. For (I), (II) and (III), all H atoms were located in difference Fourier maps. Except for the methyl H atoms of (III), H atoms bonded to C atoms were refined using a riding model, with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C). The methyl H atoms were refined using a riding model, with C—H = 0.98 Å and U_iso(H) = 1.5U_eq(C). All H atoms bonded to N or O atoms were refined freely, including isotropic displacement parameters.

In the early stages of the refinement of (I), it was discovered that the 2-(furan-2-yl)benzimidazole moiety exhibited approximately twofold disorder, pivoting on the methyl­ene group of the furan-2-yl­methyl substituent. The disorder was modeled using the metrics of the major component. For the minor component, similarity restraints were used for the bond distances and anisotropic displacement parameters were constrained to those of the major component. The occupancies refined to 0.7358 (19):0.2642 (19).

Compounds (II) and (III) exhibited approximately twofold disorder in the 2-furan substituent. For each, the minor component was modeled using the metrics of the major component. Similarity restraints were used for the bond distances of the minor components. For (II), anisotropic displacement parameters of the disordered methyl­furan units were restrained to be more isotropic. For (III), the anisotropic displacement parameters were constrained to those of the major component. The occupancies refined to 0.59 (2):0.41 (2) for (II) and to 0.608 (9):0.392 (9) for (III).

S2.3. Computations

All calculations were performed using the Spartan '14 (Wavefunction, 2014) package. All results refer to systems in the gas phase. Energy-minimized structures were obtained using M06-2X density functionals (Zhao & Truhlar, 2008) with a 6-311+G(d,p) basis set. In the calculation of inter­action energies, M06, M06-2X, and B3LYP functionals were used along with a series of basis sets in an effort to choose a combination of functional and basis set that gave good values with a minimum of computational expense. With the exception of the B3LYP functional which gave an unfavorable inter­action energy when corrected for BSSE, all of the combinations examined gave similar results. The poor results obtained for inter­action energies using the B3LYP functional has been observed for other systems involving dispersion or hydrogen-bonding inter­actions (Walker et al., 2013). The M06-2X/6-31+G(d) combination of functional and basis set has been shown to reproduce inter­action energies obtained using a more rigorous approach at a reduced computational cost (Wheeler & Bloom, 2014; Wheeler & Houk, 2008; Wheeler et al., 2010; Wells et al., 2013; Walker et al., 2013). Inter­action energies were corrected for basis set superposition energy (BSSE) using the counterpoise (CP) method. Because bond distances involving H atoms that are obtained from X-ray analysis are systematically short, calculations employed the crystal coordinates for nonhydrogen atoms and optimized [M06-2X/6-31+G(d)] coordinates for hydrogen atoms. For (II) and (III), the hydrogen halide and water of hydration were not included in the calculation.

S3. Results and discussion

The molecular structure of (I) is shown in Fig. 1. The approximately twofold rotational disorder observed for the 2-(furan-2-yl)benzimidazole ring system has precedence (Geiger & Isaac, 2014). The benzimidazole is almost planar with the largest deviation for atom C5 [0.033 (4) Å] in the major component and for atom C54 [0.034 (14) Å] in the minor component. The plane of the furan substituent is canted 12.7 (3)° from that of the benzimidazole ring system in the major component and by 15.2 (8)° in the minor component.

As seen in Fig. 2, the extended structure exhibits chains parallel to the c axis. There are two sets of stacking inter­actions involving molecules related by inversion centers. The first, hereafter referred to as (Ia) and shown in the center of Fig. 2, exhibits a π–π aromatic inter­action between furan substituents. In the descriptions that follow, Fn, MeFn, Im and Bz refer to furan, furan-2-yl­methyl, imidazole and benzene rings, respectively. The Cg(Fn)···Cg(Fn)ⁱ distance is 3.631 (3) Å (for symmetry codes, see Fig. 2). The pair of molecules also displays two C10—H10···π(MeFn) aromatic inter­actions [H10···Cg(MeFn)ⁱ = 3.27 Å and C10—H10···Cg(MeFn)ⁱ = 121°]. In the minor contributor to the disorder model, the corresponding inter­actions are Cg(Bz)···Cg(Bz)ⁱ = 3.542 (7) Å, with two C54—H54···π(MeFn) inter­actions [H54···Cg(MeFn)ⁱ = 2.95 Å and C54—H54···Cg(MeFn)ⁱ = 130°]. The second stacking inter­action, shown at the sides of Fig. 2 and hereafter referred to as (Ib), involves symmetry-related benzimidazole moieties, which are laterally (i.e. along the minor molecular axis) shifted from one another. The inter­molecular Cg(Im)···Cg(Bz) distance is 3.9601 (5) Å. Projections showing the stacking of the rings are shown in Fig. 3. Two additional (shorter) C—H···π inter­actions between chains join (Ia) to (Ib) to form the extended network [H3···Cg(Fn)^v = 2.96 Å and C3—H3···Cg(Fn)^v = 137°; H14ⁱ···Cg(Bz)^iv = 2.96 Å and C14ⁱ—H14ⁱ···Cg(Bz)^iv = 144°].

Fig. 4 shows the molecular structure of (II). Protonation of the imidazole results in only minor structural changes. The protonated benzimidazole is essentially planar, with the maximum deviation being for atom C7 [0.016 (3) Å]. The major and minor contributors to the disordered 2-furan substituent form angles of 2.7 (13) and 31.2 (15)°, respectively, to the benzimidazole mean plane. The extended structure of (II) is shown in Fig. 5. The packing of the ions is dominated by hydrogen bonding involving the protonated amine, water, and chloride ion, resulting in chains that run parallel to the a axis (Table 2). The benzimidazole cations are stacked in a shifted head-to-head arrangement (see Fig. 3) with primary stacking inter­actions involving the benzimidazole rings of one molecule with the 2-furan substituent and imidazole ring of another molecule translated along the a axis. The inter­molecular Cg(Im)···Cg(Bz)ⁱ distance is 3.7615 (5) Å and the Cg(Im)···Cg(Fn)ⁱⁱ distance is 3.7631 (4) Å (for symmetry codes, see Fig. 5).

The molecular structure of (III) is shown in Fig. 6. The corresponding bond distances and angles agree well with those found for (II). The greatest deviation from planarity in the benzimidazole ring system occurs for atom C7 [0.0104 (16) Å]. The plane of the 2-furan substituent is canted from the that of benzimidazole by 5(2) and 5(4)° for the major and minor contributors to the disorder, respectively. Fig. 7 shows a packing diagram for (III). N—H···Br hydrogen bonding involves discrete cation–anion pairs (Table 3). Benzimidazolium cations related by inversion centers are π-stacked and have a slipped head-to-tail arrangment of the benzimidazole moiety (see Fig. 3). Atom C7 is located roughly over Cg(Bz) with C7···Cg(Bz)ⁱ = 3.443 (2) Å.

As a result of the approximately twofold disorder exhibited by the benzimidazole ring system in (I), in addition to the π(Fn)–π(Fn) stacking, π(Bz)–π(Bz) stacking [Cg(Bz)···Cg(Bz)ⁱ = 3.542 (7) Å] and π(Bz)–π(Fn) stacking [Cg(Bz)···Cg(Fn)ⁱ = 3.543 (7) Å] inter­actions involving the minor contributors to the disorder are present. The three compounds reported thus provide an opportunity to explore π(Fn)···π(Fn), π(Bz)···π(Bz), and π(Fn)···π(Bz) inter­actions. Density functional theory (DFT) calculations were performed using the atomic coordinates of heavy atoms obtained in the crystallographic analysis and optimized H-atom positions. The results are shown in Table 4.

In an effort to deconvolute the C—H···π and π–π inter­action energies for (Ia), calculations were also performed on pairs of molecules in which the 1-(furan-2-yl­methyl) substituent was replaced by an H atom. Assuming that the difference in inter­action energies corresponds to the two Fn–Fn C—H···π inter­actions present in (Ia), the value obtained for each C—H···π inter­action is -9.4 kJ mol^-1. An independent calculation involving two furan molecules in the orientation observed in (Ia) yields a BSSE-corrected value of -7.7 kJ mol^-1. These values agree well with the -9.8 kJ mol^-1 obtained for an optimized ethyne–furan inter­action energy (Sánchez-García & Jansen, 2012). A similar analysis using the minor contributor to the disorder in (Ia) yields a value of -8.8 kJ mol^-1 for the Bz–Bz C—H···π inter­action, which is in good agrement with the value of -9.4 kJ mol^-1 reported for the inter­action energy of a `T-shaped' benzene dimer (Sherrill et al., 2009).

The results suggest that π(Fn)–π(Fn) is more favorable than π(Bz)–π(Bz) or π(Fn)–π(Bz) and support the proposition that noncovalent inter­actions involving aromatic rings have an electrostatic component (Wheeler & Bloom, 2014). In benzimidazole, the presence of the imidazole `substitutent' on the benzene ring results in an unsymmetrical electron distribution with the bridgehead C atoms exhibiting postive character. Further evidence comes from inter­action (Ib), in which the molecular dipoles of paired molecules are aligned to provide favorable electrostatic inter­action. [The calculated dipole moment, M06-2X/6-311+G(d,p), in the energy-minimized structure is 3.6 Debye.]

The inter­action energies for the benzimidazoles in the orientations found in (II) and (III) were calculated using optimized H-atom coordinates and removal of the hydrogen chloride and water for (II), and removal of the hydrogen bromide for (III). The results suggest that an increase in the number of aromatic rings involved in the inter­action results in a more favorable inter­action. This observation is consistent with that found for a series of polynuclear aromatic molecules where the inter­action energies for sandwiched pairs of benzene, napthalene, anthracene and tetra­cene were found to be -11, -28, -48 and -68 kJ mol^-1, respectively (Grimme, 2008). For comparison, the N—H···OH₂ hydrogen-bond energy was found to be 125.6 and 122.4 kJ mol^-1 using the M06-2X and B3LYP functionals, respectively, with a 6-31+G(d) basis set.

A comparison of the inter­action energies of (Ia), (Ib), (II) and (III) suggests that the strength of the inter­action depends on the relative orientation of the molecules with respect to shift along the molecular axes. In order to further explore the effect of orientation of the paired 2-(furan-2-yl)benzimidazole molecules with respect to each other, three parameters were examined, viz. inter­planar spacing, shift (along the major molecular axis) and lateral shift (along the minor molecular axis). Fig. 8(a) shows a plot of the relative energy for pairs of molecules as a function of the inter­planar spacing, Fig. 8(b) shows the effect of slip distance on the energy of the pairs of molecules, and the effect of lateral shift on the energy is shown in Fig. 8(c). Unsubstituted benzimidazole crystallizes in at least two different forms in which molecules are joined in hydrogen-bonded chains. In the thermodynamically more stable α crystalline form of benzimidazole (Pna2₁), pairs of molecules exhibit C—H···Cg(Bz) = 2.639 (16) Å π inter­actions (Stibrany et al., 2001). In the β form (Pccn), pairs of molecules related by inversion centers display a Cg(Im)···Cg(Im) = 3.4838 (11) Å distance, with a shift along the major axis of 0.59 Å, and a lateral shift of zero (Krawczyk & Gdaniec, 2005).

Although there has been much computational work in the area of noncovalent inter­actions, most studies have involved artificial systems (Wheeler & Bloom, 2014). A notable exception is the determination of inter­action energies between cytosine and aspartic or glutamic acids (Wells et al., 2013). The results reported herein are for a real system that is of inherent inter­est in diverse areas of inquiry. The calculated inter­action energies of the 2-(furanyl)-1-(furan-2-yl­methyl)-substituted benzimidazoles are strongly correlated with inter­planar spacing and relative orientation of the inter­acting molecules. Although the π–π inter­action energy is less favorable in (Ia) than in (Ib), the additional inter­actions between the furan rings may help stabilize (Ia), leading to an overall more favorable inter­action.

Related literature

For related literature, see: Akkurt et al. (2009); Chai et al. (2014); Chirachanchai et al. (2011); Demont et al. (2014); Dik-Edixhoven, Schenk & Van Der Meer (1973); El Ghozlani, Rakib, Medaghri-Alaoui, Saadi & El Ammari (2014); Escande & Galigné (1974); Fathima et al. (2013); Fuente et al. (2010); Geiger & Isaac (2014); Geiger et al. (2012); Geiger, Donohoe & Geiger (2014); Grimme (2008); Hayashi et al. (2009); Horton et al. (2003); Krawczyk & Gdaniec (2005); Krishnamurthy et al. (2013); López-Rodríguez, Benhamú, Morcillo, Tejeda, Orensanz, Alfaro & Martín (1999); Laughton et al. (1996); Li et al. (2011); MacBean (2013); Mallena et al. (2004); Matolcsy et al. (1989); McGaughey et al. (1998); Munch et al. (2001); Nishio (2005); Pangon et al. (2011); Patel et al. (2008); Perin et al. (2014); Rachocki et al. (2014); Ran & Wong (2006); Sánchez-García & Jansen (2012); Sherrill et al. (2009); Stibrany et al. (2001); Takahashi et al. (2010); Totsatitpaisan et al. (2008); Trent et al. (1996); Varala et al. (2007); Walker et al. (2013); Wavefunction (2014); Wells et al. (2013); Wheeler & Bloom (2014); Wheeler & Houk (2008); Wheeler et al. (2010); Yeong et al. (2013); Zhao & Truhlar (2008).

Computing details

For all compounds, data collection: APEX2 (Bruker, 2013); cell refinement: APEX2 (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009) and Mercury (Macrae et al., 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. Perspective view of (I), showing the atom-labeling scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level. Only the major contributor to the disorder model is shown.
	Fig. 2. Partial packing diagram for (I), showing the chains running parallel to the c axis, resulting in two types of head-to-tail stacking, denoted types (Ia) and (Ib). Only the major contributor to the disorder model and H atoms involved in C—H···π interactions are shown. [Symmetry codes: (i) -x+1, -y, -z+1; (ii) x, y, z+1; (iii) -x+1, -y, -z; (iv) x+1/2, -y+1/2, z+1/2; (v) -x+3/2, y+1/2, -z+1/2; (vi) -x+3/2, y+1/2, -z+3/2.]
	Fig. 3. Projections representing the stacking interactions observed in (I), (II) and (III). The furan ring of the methylfuran substitutent is not shown. Only the major contributors to the disorder models are represented.
	Fig. 4. Perspective view of (II), showing the atom-labeling scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level. Only the major contributor to the disorder model is shown.
	Fig. 5. Partial packing diagram of (II), showing the head-to-head stacking and the hydrogen-bonding network, resulting in chains parallel to the a axis. H atoms not involved in hydrogen bonding have been omitted and only the major contributor to the disorder model is shown. [Symmetry codes: (i) x-1, y, z; (ii) x+1, y, z.]
	Fig. 6. Perspective view of (III), showing the atom-labeling scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level. Only the major contributor to the disorder model is shown.
	Fig. 7. Packing diagram of (III), displaying the N—H···Br hydrogen bonding and the head-to-tail stacking between inversion-center-related molecules. Only the H atoms involved in hydrogen bonding and the major contributor to the disorder model are shown. [Symmetry codes: (i) -x, -y+2, -z; (ii) -x, -y+1, -z; (iii) x, y-1, z; (iv) x, y-2, z+1; (v) -x, -y+1, -z+1; (vi) x, y, z+1; (vii) -x, -y+2, -z+1.]
	Fig. 8. The effect of (a) the interplanar spacing, (b) the shift along the major molecular axis and (c) the lateral shift along the minor molecular axis on the relative interaction energy for the head-to-head (blue) and head-to-tail (red) alignments of 2-(furan-2-yl)benzimidazole.

(I) 2-(Furan-2-yl)-1-[(furan-2-yl)methyl]-1H-benzimidazole

Crystal data

C16H12N2O2	F(000) = 552
Mr = 264.28	Dx = 1.381 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 9.3916 (17) Å	Cell parameters from 2501 reflections
b = 12.398 (2) Å	θ = 2.5–24.7°
c = 11.313 (2) Å	µ = 0.09 mm^−1
β = 105.216 (6)°	T = 200 K
V = 1271.1 (4) Å^3	Prism, clear orange
Z = 4	0.60 × 0.40 × 0.40 mm

Data collection

Bruker SMART X2S benchtop diffractometer	2241 independent reflections
Radiation source: sealed microfocus tube	1764 reflections with I > 2σ(I)
Doubly curved silicon crystal monochromator	Rint = 0.029
Detector resolution: 8.3330 pixels mm^-1	θmax = 25.1°, θmin = 2.5°
ω scans	h = −11→11
Absorption correction: multi-scan (SADABS; Bruker, 2013)	k = −13→14
Tmin = 0.89, Tmax = 0.96	l = −12→13
8001 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.104	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0363P)^2 + 0.3973P] where P = (Fo^2 + 2Fc^2)/3
2241 reflections	(Δ/σ)max < 0.001
227 parameters	Δρmax = 0.13 e Å^−3
25 restraints	Δρmin = −0.18 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.4237 (3)	0.0890 (2)	0.0903 (2)	0.0313 (6)	0.7358 (19)
C2	0.5574 (3)	0.13910 (19)	0.1462 (2)	0.0309 (5)	0.7358 (19)
C3	0.6003 (3)	0.2294 (3)	0.0950 (3)	0.0360 (8)	0.7358 (19)
H3	0.6925	0.2628	0.1315	0.043*	0.7358 (19)
C4	0.5096 (3)	0.2704 (4)	−0.0082 (4)	0.0407 (9)	0.7358 (19)
H4	0.5386	0.3338	−0.0431	0.049*	0.7358 (19)
C5	0.3736 (5)	0.2221 (5)	−0.0656 (5)	0.0518 (12)	0.7358 (19)
H5	0.3108	0.2541	−0.1366	0.062*	0.7358 (19)
C6	0.3298 (5)	0.1249 (4)	−0.0170 (3)	0.0428 (9)	0.7358 (19)
H6	0.2416	0.0877	−0.0563	0.051*	0.7358 (19)
N1	0.4129 (3)	0.0010 (2)	0.1649 (2)	0.0320 (6)	0.7358 (19)
N2	0.6273 (4)	0.0834 (4)	0.2537 (3)	0.0313 (8)	0.7358 (19)
C7	0.5371 (2)	0.00446 (18)	0.2610 (2)	0.0307 (5)	0.7358 (19)
O1	0.4764 (3)	−0.1518 (3)	0.3722 (4)	0.0472 (7)	0.7358 (19)
C8	0.5664 (3)	−0.0645 (2)	0.3674 (2)	0.0328 (6)	0.7358 (19)
C9	0.6695 (4)	−0.0567 (3)	0.4774 (4)	0.0377 (9)	0.7358 (19)
H9	0.7458	−0.0044	0.4997	0.045*	0.7358 (19)
C10	0.6407 (5)	−0.1420 (3)	0.5523 (4)	0.0402 (9)	0.7358 (19)
H10	0.6946	−0.1582	0.6338	0.048*	0.7358 (19)
C11	0.5240 (9)	−0.1943 (5)	0.4860 (7)	0.0473 (13)	0.7358 (19)
H11	0.4794	−0.2541	0.5146	0.057*	0.7358 (19)
C12	0.2886 (18)	−0.0743 (12)	0.1348 (13)	0.0354 (9)	0.7358 (19)
H12A	0.3242	−0.146	0.1685	0.043*	0.7358 (19)
H12B	0.2551	−0.0816	0.0446	0.043*	0.7358 (19)
C51	0.4865 (8)	−0.0782 (6)	0.3159 (7)	0.0313 (6)	0.2642 (19)
C52	0.6127 (7)	−0.0162 (6)	0.3668 (7)	0.0309 (5)	0.2642 (19)
C53	0.7059 (13)	−0.0359 (11)	0.4784 (12)	0.0360 (8)	0.2642 (19)
H53	0.7913	0.0069	0.5103	0.043*	0.2642 (19)
C54	0.6709 (16)	−0.1194 (11)	0.5417 (14)	0.0407 (9)	0.2642 (19)
H54	0.7316	−0.1331	0.6217	0.049*	0.2642 (19)
C55	0.549 (3)	−0.188 (2)	0.495 (2)	0.0518 (12)	0.2642 (19)
H55	0.5323	−0.2486	0.5408	0.062*	0.2642 (19)
C56	0.4458 (16)	−0.1633 (14)	0.3744 (17)	0.0428 (9)	0.2642 (19)
H56	0.3589	−0.204	0.3409	0.051*	0.2642 (19)
N51	0.4169 (9)	−0.0312 (6)	0.2055 (8)	0.0320 (6)	0.2642 (19)
N52	0.6201 (14)	0.0689 (13)	0.2877 (10)	0.0313 (8)	0.2642 (19)
C57	0.5035 (7)	0.0567 (5)	0.1939 (6)	0.0307 (5)	0.2642 (19)
O51	0.3306 (11)	0.1447 (7)	0.0109 (8)	0.0472 (7)	0.2642 (19)
C58	0.4687 (10)	0.1333 (6)	0.0957 (8)	0.0328 (6)	0.2642 (19)
C59	0.5548 (11)	0.2130 (9)	0.0688 (10)	0.0377 (9)	0.2642 (19)
H59	0.6546	0.228	0.1105	0.045*	0.2642 (19)
C60	0.4665 (14)	0.2697 (12)	−0.0338 (12)	0.0402 (9)	0.2642 (19)
H60	0.4958	0.3303	−0.073	0.048*	0.2642 (19)
C61	0.3392 (18)	0.2234 (12)	−0.0636 (16)	0.0473 (13)	0.2642 (19)
H61	0.2609	0.2441	−0.1317	0.057*	0.2642 (19)
C62	0.282 (5)	−0.074 (3)	0.124 (4)	0.0354 (9)	0.2642 (19)
H62A	0.2887	−0.1534	0.1167	0.043*	0.2642 (19)
H62B	0.2649	−0.0419	0.0412	0.043*	0.2642 (19)
O2	0.09722 (14)	0.05435 (11)	0.14736 (13)	0.0475 (4)
C13	0.15930 (19)	−0.04412 (14)	0.18073 (17)	0.0363 (4)
C14	0.0869 (2)	−0.09514 (17)	0.2515 (2)	0.0524 (6)
H14	0.1083	−0.1648	0.2866	0.063*
C15	−0.0283 (2)	−0.02500 (18)	0.2642 (2)	0.0523 (6)
H15	−0.0984	−0.0387	0.3095	0.063*
C16	−0.0184 (2)	0.06288 (18)	0.2007 (2)	0.0518 (6)
H16	−0.0821	0.1235	0.1929	0.062*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0307 (14)	0.0315 (13)	0.0322 (13)	0.0019 (10)	0.0090 (11)	−0.0040 (11)
C2	0.0256 (12)	0.0325 (12)	0.0358 (14)	0.0017 (10)	0.0103 (11)	−0.0059 (11)
C3	0.0304 (17)	0.0412 (17)	0.0378 (18)	−0.0001 (13)	0.0116 (12)	−0.0004 (13)
C4	0.036 (2)	0.0445 (16)	0.043 (2)	−0.0006 (17)	0.0141 (15)	0.0064 (16)
C5	0.044 (3)	0.076 (2)	0.0336 (19)	0.015 (2)	0.0089 (18)	0.0186 (17)
C6	0.0360 (15)	0.053 (2)	0.039 (2)	−0.0008 (14)	0.0088 (15)	−0.0106 (14)
N1	0.0262 (9)	0.0336 (17)	0.0364 (19)	−0.0030 (11)	0.0084 (12)	−0.0043 (11)
N2	0.0277 (9)	0.0330 (16)	0.034 (2)	−0.0002 (9)	0.0094 (14)	−0.0006 (16)
C7	0.0290 (12)	0.0301 (13)	0.0350 (15)	0.0041 (10)	0.0120 (11)	−0.0026 (10)
O1	0.0460 (18)	0.0394 (13)	0.0553 (13)	−0.0010 (12)	0.0117 (14)	0.0083 (11)
C8	0.0329 (15)	0.0284 (13)	0.0400 (15)	0.0031 (12)	0.0149 (12)	−0.0008 (12)
C9	0.036 (2)	0.038 (2)	0.0403 (16)	0.0031 (14)	0.0124 (15)	0.0018 (16)
C10	0.051 (3)	0.036 (2)	0.0351 (17)	0.0127 (16)	0.0151 (15)	0.0097 (14)
C11	0.060 (4)	0.0326 (18)	0.054 (3)	0.0104 (18)	0.024 (2)	0.0148 (17)
C12	0.0337 (18)	0.0358 (10)	0.038 (3)	−0.0079 (10)	0.0110 (19)	−0.0081 (14)
C51	0.0307 (14)	0.0315 (13)	0.0322 (13)	0.0019 (10)	0.0090 (11)	−0.0040 (11)
C52	0.0256 (12)	0.0325 (12)	0.0358 (14)	0.0017 (10)	0.0103 (11)	−0.0059 (11)
C53	0.0304 (17)	0.0412 (17)	0.0378 (18)	−0.0001 (13)	0.0116 (12)	−0.0004 (13)
C54	0.036 (2)	0.0445 (16)	0.043 (2)	−0.0006 (17)	0.0141 (15)	0.0064 (16)
C55	0.044 (3)	0.076 (2)	0.0336 (19)	0.015 (2)	0.0089 (18)	0.0186 (17)
C56	0.0360 (15)	0.053 (2)	0.039 (2)	−0.0008 (14)	0.0088 (15)	−0.0106 (14)
N51	0.0262 (9)	0.0336 (17)	0.0364 (19)	−0.0030 (11)	0.0084 (12)	−0.0043 (11)
N52	0.0277 (9)	0.0330 (16)	0.034 (2)	−0.0002 (9)	0.0094 (14)	−0.0006 (16)
C57	0.0290 (12)	0.0301 (13)	0.0350 (15)	0.0041 (10)	0.0120 (11)	−0.0026 (10)
O51	0.0460 (18)	0.0394 (13)	0.0553 (13)	−0.0010 (12)	0.0117 (14)	0.0083 (11)
C58	0.0329 (15)	0.0284 (13)	0.0400 (15)	0.0031 (12)	0.0149 (12)	−0.0008 (12)
C59	0.036 (2)	0.038 (2)	0.0403 (16)	0.0031 (14)	0.0124 (15)	0.0018 (16)
C60	0.051 (3)	0.036 (2)	0.0351 (17)	0.0127 (16)	0.0151 (15)	0.0097 (14)
C61	0.060 (4)	0.0326 (18)	0.054 (3)	0.0104 (18)	0.024 (2)	0.0148 (17)
C62	0.0337 (18)	0.0358 (10)	0.038 (3)	−0.0079 (10)	0.0110 (19)	−0.0081 (14)
O2	0.0410 (7)	0.0499 (8)	0.0540 (9)	0.0063 (6)	0.0166 (6)	0.0032 (7)
C13	0.0321 (9)	0.0355 (10)	0.0415 (11)	−0.0061 (8)	0.0097 (8)	−0.0100 (8)
C14	0.0510 (12)	0.0448 (11)	0.0702 (15)	−0.0059 (10)	0.0315 (11)	−0.0008 (11)
C15	0.0391 (11)	0.0655 (14)	0.0593 (14)	−0.0064 (10)	0.0254 (10)	−0.0095 (12)
C16	0.0355 (11)	0.0649 (14)	0.0571 (14)	0.0103 (10)	0.0161 (10)	−0.0053 (12)

Geometric parameters (Å, º)

C1—C6	1.374 (5)	C52—N52	1.397 (15)
C1—C2	1.395 (4)	C53—C54	1.348 (13)
C1—N1	1.399 (4)	C53—H53	0.95
C2—C3	1.369 (4)	C54—C55	1.412 (19)
C2—N2	1.403 (4)	C54—H54	0.95
C3—C4	1.351 (5)	C55—C56	1.482 (18)
C3—H3	0.95	C55—H55	0.95
C4—C5	1.406 (6)	C56—H56	0.95
C4—H4	0.95	N51—C57	1.387 (9)
C5—C6	1.429 (7)	N51—C62	1.46 (4)
C5—H5	0.95	N52—C57	1.318 (12)
C6—H6	0.95	C57—C58	1.433 (11)
N1—C7	1.371 (3)	O51—C61	1.306 (14)
N1—C12	1.464 (15)	O51—C58	1.404 (12)
N2—C7	1.311 (4)	C58—C59	1.361 (12)
C7—C8	1.443 (4)	C59—C60	1.422 (13)
O1—C11	1.354 (6)	C59—H59	0.95
O1—C8	1.383 (4)	C60—C61	1.289 (18)
C8—C9	1.365 (5)	C60—H60	0.95
C9—C10	1.425 (4)	C61—H61	0.95
C9—H9	0.95	C62—C13	1.51 (5)
C10—C11	1.324 (7)	C62—H62A	0.99
C10—H10	0.95	C62—H62B	0.99
C11—H11	0.95	O2—C13	1.363 (2)
C12—C13	1.489 (19)	O2—C16	1.378 (2)
C12—H12A	0.99	C13—C14	1.337 (3)
C12—H12B	0.99	C14—C15	1.424 (3)
C51—C56	1.352 (14)	C14—H14	0.95
C51—N51	1.378 (11)	C15—C16	1.322 (3)
C51—C52	1.403 (9)	C15—H15	0.95
C52—C53	1.357 (13)	C16—H16	0.95
C6—C1—C2	123.3 (3)	C52—C53—H53	121.8
C6—C1—N1	130.9 (3)	C53—C54—C55	123.4 (14)
C2—C1—N1	105.8 (2)	C53—C54—H54	118.3
C3—C2—C1	120.2 (3)	C55—C54—H54	118.3
C3—C2—N2	130.3 (3)	C54—C55—C56	119.4 (15)
C1—C2—N2	109.6 (2)	C54—C55—H55	120.3
C4—C3—C2	119.0 (3)	C56—C55—H55	120.3
C4—C3—H3	120.5	C51—C56—C55	114.2 (13)
C2—C3—H3	120.5	C51—C56—H56	122.9
C3—C4—C5	121.9 (4)	C55—C56—H56	122.9
C3—C4—H4	119.0	C51—N51—C57	105.5 (7)
C5—C4—H4	119.0	C51—N51—C62	123.2 (18)
C4—C5—C6	120.0 (4)	C57—N51—C62	131.3 (19)
C4—C5—H5	120.0	C57—N52—C52	105.0 (9)
C6—C5—H5	120.0	N52—C57—N51	113.5 (9)
C1—C6—C5	115.5 (4)	N52—C57—C58	121.4 (8)
C1—C6—H6	122.3	N51—C57—C58	125.1 (7)
C5—C6—H6	122.3	C61—O51—C58	108.2 (10)
C7—N1—C1	105.8 (2)	C59—C58—O51	105.7 (8)
C7—N1—C12	131.7 (6)	C59—C58—C57	128.8 (9)
C1—N1—C12	122.5 (6)	O51—C58—C57	125.3 (8)
C7—N2—C2	105.0 (3)	C58—C59—C60	106.7 (9)
N2—C7—N1	113.7 (3)	C58—C59—H59	126.7
N2—C7—C8	120.7 (3)	C60—C59—H59	126.7
N1—C7—C8	125.4 (2)	C61—C60—C59	107.2 (12)
C11—O1—C8	106.8 (3)	C61—C60—H60	126.4
C9—C8—O1	108.4 (3)	C59—C60—H60	126.4
C9—C8—C7	130.7 (3)	C60—C61—O51	112.0 (14)
O1—C8—C7	120.8 (3)	C60—C61—H61	124.0
C8—C9—C10	106.8 (3)	O51—C61—H61	124.0
C8—C9—H9	126.6	N51—C62—C13	106 (3)
C10—C9—H9	126.6	N51—C62—H62A	110.6
C11—C10—C9	106.6 (4)	C13—C62—H62A	110.6
C11—C10—H10	126.7	N51—C62—H62B	110.6
C9—C10—H10	126.7	C13—C62—H62B	110.6
C10—C11—O1	111.5 (4)	H62A—C62—H62B	108.7
C10—C11—H11	124.3	C13—O2—C16	106.05 (15)
O1—C11—H11	124.3	C14—C13—O2	110.00 (16)
N1—C12—C13	115.6 (10)	C14—C13—C12	132.8 (6)
N1—C12—H12A	108.4	O2—C13—C12	117.2 (6)
C13—C12—H12A	108.4	C14—C13—C62	134.8 (17)
N1—C12—H12B	108.4	O2—C13—C62	115.0 (16)
C13—C12—H12B	108.4	C13—C14—C15	106.88 (19)
H12A—C12—H12B	107.4	C13—C14—H14	126.6
C56—C51—N51	130.2 (10)	C15—C14—H14	126.6
C56—C51—C52	122.9 (9)	C16—C15—C14	106.55 (18)
N51—C51—C52	106.8 (6)	C16—C15—H15	126.7
C53—C52—N52	127.2 (9)	C14—C15—H15	126.7
C53—C52—C51	123.5 (8)	C15—C16—O2	110.52 (18)
N52—C52—C51	109.3 (7)	C15—C16—H16	124.7
C54—C53—C52	116.4 (11)	O2—C16—H16	124.7
C54—C53—H53	121.8
C6—C1—C2—C3	0.6 (4)	N51—C51—C56—C55	−177.9 (17)
N1—C1—C2—C3	−179.7 (3)	C52—C51—C56—C55	−2 (2)
C6—C1—C2—N2	−180.0 (3)	C54—C55—C56—C51	4 (3)
N1—C1—C2—N2	−0.3 (3)	C56—C51—N51—C57	176.7 (12)
C1—C2—C3—C4	1.7 (5)	C52—C51—N51—C57	0.1 (9)
N2—C2—C3—C4	−177.5 (4)	C56—C51—N51—C62	−5 (3)
C2—C3—C4—C5	−1.0 (6)	C52—C51—N51—C62	179 (2)
C3—C4—C5—C6	−2.0 (7)	C53—C52—N52—C57	−177.4 (10)
C2—C1—C6—C5	−3.4 (4)	C51—C52—N52—C57	−0.4 (12)
N1—C1—C6—C5	177.0 (3)	C52—N52—C57—N51	0.5 (13)
C4—C5—C6—C1	4.0 (6)	C52—N52—C57—C58	176.5 (7)
C6—C1—N1—C7	−179.2 (3)	C51—N51—C57—N52	−0.4 (12)
C2—C1—N1—C7	1.2 (3)	C62—N51—C57—N52	−179 (3)
C6—C1—N1—C12	1.4 (9)	C51—N51—C57—C58	−176.3 (6)
C2—C1—N1—C12	−178.2 (8)	C62—N51—C57—C58	5 (3)
C3—C2—N2—C7	178.6 (3)	C61—O51—C58—C59	2.7 (13)
C1—C2—N2—C7	−0.7 (4)	C61—O51—C58—C57	178.8 (10)
C2—N2—C7—N1	1.5 (4)	N52—C57—C58—C59	13.6 (15)
C2—N2—C7—C8	−174.0 (2)	N51—C57—C58—C59	−170.8 (10)
C1—N1—C7—N2	−1.7 (4)	N52—C57—C58—O51	−161.6 (10)
C12—N1—C7—N2	177.5 (10)	N51—C57—C58—O51	13.9 (12)
C1—N1—C7—C8	173.5 (2)	O51—C58—C59—C60	−1.1 (12)
C12—N1—C7—C8	−7.2 (10)	C57—C58—C59—C60	−177.1 (9)
C11—O1—C8—C9	1.3 (6)	C58—C59—C60—C61	−0.8 (16)
C11—O1—C8—C7	−174.8 (5)	C59—C60—C61—O51	2.6 (19)
N2—C7—C8—C9	8.8 (5)	C58—O51—C61—C60	−3.4 (17)
N1—C7—C8—C9	−166.2 (3)	C51—N51—C62—C13	76 (3)
N2—C7—C8—O1	−176.0 (3)	C57—N51—C62—C13	−106 (3)
N1—C7—C8—O1	9.0 (4)	C16—O2—C13—C14	−0.1 (2)
O1—C8—C9—C10	−0.3 (4)	C16—O2—C13—C12	−180.0 (6)
C7—C8—C9—C10	175.3 (3)	C16—O2—C13—C62	175.5 (16)
C8—C9—C10—C11	−0.8 (6)	N1—C12—C13—C14	−123.9 (8)
C9—C10—C11—O1	1.7 (8)	N1—C12—C13—O2	56.0 (11)
C8—O1—C11—C10	−1.9 (8)	N1—C12—C13—C62	120.30
C7—N1—C12—C13	92.5 (11)	N51—C62—C13—C14	−98 (3)
C1—N1—C12—C13	−88.3 (10)	N51—C62—C13—O2	88 (2)
C56—C51—C52—C53	0.4 (16)	N51—C62—C13—C12	−30.30
N51—C51—C52—C53	177.3 (10)	O2—C13—C14—C15	0.0 (2)
C56—C51—C52—N52	−176.7 (12)	C12—C13—C14—C15	179.9 (7)
N51—C51—C52—N52	0.2 (10)	C62—C13—C14—C15	−174 (2)
N52—C52—C53—C54	175.8 (13)	C13—C14—C15—C16	0.1 (2)
C51—C52—C53—C54	−0.8 (18)	C14—C15—C16—O2	−0.2 (2)
C52—C53—C54—C55	3 (3)	C13—O2—C16—C15	0.2 (2)
C53—C54—C55—C56	−4 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C12—H12A···O1	0.99	2.37	2.959 (15)	117
C62—H62B···O51	0.99	2.44	3.08 (5)	122
C6—H6···C15^i	0.95	2.77	3.635 (5)	152
C5—H5···N2^ii	0.95	2.73	3.587 (6)	151

Symmetry codes: (i) −x, −y, −z; (ii) x−1/2, −y+1/2, z−1/2.

(II) 2-(Furan-2-yl)-1-[(furan-2-yl)methyl]-1H-benzimidazol-3-ium chloride monohydrate

Crystal data

C16H13N2O2^+·Cl^−·H2O	F(000) = 664
Mr = 318.75	Dx = 1.366 Mg m^−3
Monoclinic, Cc	Mo Kα radiation, λ = 0.71073 Å
a = 4.8700 (7) Å	Cell parameters from 50 reflections
b = 18.694 (3) Å	θ = 5.4–19.0°
c = 17.196 (3) Å	µ = 0.26 mm^−1
β = 98.050 (5)°	T = 200 K
V = 1550.1 (4) Å^3	Plate, colorless
Z = 4	0.60 × 0.50 × 0.20 mm

Data collection

Bruker SMART X2S benchtop diffractometer	2685 independent reflections
Radiation source: sealed microfocus tube	2420 reflections with I > 2σ(I)
Doubly curved silicon crystal monochromator	Rint = 0.067
Detector resolution: 8.3330 pixels mm^-1	θmax = 25.0°, θmin = 2.5°
ω scans	h = −5→5
Absorption correction: multi-scan (SADABS; Bruker, 2013)	k = −22→22
Tmin = 0.86, Tmax = 0.95	l = −20→20
7314 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.037	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.094	w = 1/[σ^2(Fo^2) + (0.0276P)^2 + 0.1149P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max < 0.001
2685 reflections	Δρmax = 0.15 e Å^−3
257 parameters	Δρmin = −0.21 e Å^−3
92 restraints	Absolute structure: Flack x determined using 1034 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.10 (5)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Cl1	0.74733 (17)	0.86438 (5)	0.26747 (6)	0.0453 (3)
OW	0.2918 (8)	0.92226 (19)	0.35666 (17)	0.0482 (8)
HWA	0.414 (10)	0.908 (2)	0.332 (3)	0.045 (13)*
HWB	0.124 (14)	0.912 (3)	0.329 (4)	0.08 (2)*
C1	0.5263 (7)	0.77492 (18)	0.5832 (2)	0.0304 (8)
C2	0.5470 (7)	0.79754 (19)	0.5078 (2)	0.0303 (8)
C3	0.7223 (8)	0.7640 (2)	0.4619 (2)	0.0360 (9)
H3	0.7367	0.7796	0.4101	0.043*
C4	0.8741 (8)	0.7070 (2)	0.4956 (2)	0.0408 (9)
H4	0.998	0.6829	0.4665	0.049*
C5	0.8500 (9)	0.6837 (2)	0.5719 (2)	0.0441 (10)
H5	0.9571	0.6439	0.5929	0.053*
C6	0.6752 (8)	0.7169 (2)	0.6172 (2)	0.0366 (9)
H6	0.6578	0.7009	0.6687	0.044*
N1	0.3381 (6)	0.82077 (16)	0.61275 (16)	0.0316 (7)
N2	0.3724 (7)	0.85629 (16)	0.49294 (18)	0.0324 (7)
H2	0.326 (12)	0.882 (3)	0.447 (3)	0.072 (16)*
C7	0.2529 (8)	0.86929 (19)	0.5563 (2)	0.0315 (8)
C8	0.065 (5)	0.9291 (11)	0.5572 (11)	0.033 (6)	0.59 (2)
C9	−0.013 (3)	0.9784 (8)	0.5015 (7)	0.057 (3)	0.59 (2)
H9	0.0401	0.9806	0.4505	0.068*	0.59 (2)
C10	−0.187 (3)	1.0257 (7)	0.5339 (7)	0.051 (3)	0.59 (2)
H10	−0.2682	1.0675	0.509	0.061*	0.59 (2)
C11	−0.222 (3)	1.0030 (7)	0.6054 (8)	0.043 (3)	0.59 (2)
H11	−0.3422	1.0236	0.6383	0.052*	0.59 (2)
O1	−0.053 (2)	0.9442 (5)	0.6227 (5)	0.046 (3)	0.59 (2)
C58	0.064 (9)	0.925 (2)	0.5647 (16)	0.047 (11)	0.41 (2)
C59	0.025 (4)	0.9630 (9)	0.6278 (10)	0.037 (4)	0.41 (2)
H59	0.1087	0.9551	0.6804	0.044*	0.41 (2)
C60	−0.164 (4)	1.0167 (11)	0.6013 (11)	0.048 (6)	0.41 (2)
H60	−0.2185	1.0549	0.6323	0.058*	0.41 (2)
C61	−0.260 (4)	1.0054 (9)	0.5230 (10)	0.045 (4)	0.41 (2)
H61	−0.4105	1.0289	0.4922	0.053*	0.41 (2)
O51	−0.090 (2)	0.9530 (6)	0.4981 (6)	0.042 (3)	0.41 (2)
C12	0.2683 (8)	0.8158 (2)	0.6934 (2)	0.0341 (8)
H12A	0.2391	0.765	0.7063	0.041*
H12B	0.0932	0.8418	0.6964	0.041*
C13	0.4924 (8)	0.8463 (2)	0.7516 (2)	0.0343 (8)
C14	0.6815 (9)	0.8176 (2)	0.8064 (2)	0.0416 (10)
H14	0.7041	0.7683	0.8191	0.05*
C15	0.8431 (10)	0.8756 (2)	0.8422 (2)	0.0478 (11)
H15	0.9926	0.8724	0.8839	0.057*
C16	0.7443 (10)	0.9350 (2)	0.8059 (3)	0.0552 (12)
H16	0.8157	0.9817	0.8172	0.066*
O2	0.5235 (6)	0.91873 (15)	0.74977 (17)	0.0494 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0534 (6)	0.0446 (5)	0.0392 (5)	−0.0003 (5)	0.0113 (4)	−0.0066 (4)
OW	0.050 (2)	0.062 (2)	0.0336 (15)	0.0073 (16)	0.0077 (15)	0.0064 (13)
C1	0.0337 (19)	0.0279 (17)	0.0297 (18)	−0.0005 (15)	0.0051 (15)	−0.0040 (14)
C2	0.031 (2)	0.0292 (18)	0.0296 (17)	−0.0018 (15)	0.0020 (15)	−0.0040 (14)
C3	0.042 (2)	0.038 (2)	0.0282 (19)	−0.0018 (17)	0.0074 (16)	−0.0055 (16)
C4	0.043 (2)	0.039 (2)	0.041 (2)	0.0114 (18)	0.0098 (18)	−0.0109 (17)
C5	0.050 (2)	0.036 (2)	0.044 (2)	0.0141 (18)	−0.0003 (18)	0.0002 (17)
C6	0.048 (2)	0.033 (2)	0.0276 (19)	0.0055 (17)	0.0021 (16)	0.0000 (14)
N1	0.0362 (17)	0.0330 (18)	0.0265 (14)	0.0011 (14)	0.0076 (13)	−0.0017 (12)
N2	0.0361 (17)	0.0340 (17)	0.0266 (16)	0.0038 (13)	0.0028 (14)	0.0023 (13)
C7	0.032 (2)	0.0320 (19)	0.0296 (18)	−0.0012 (15)	0.0029 (16)	−0.0029 (15)
C8	0.035 (8)	0.028 (7)	0.036 (6)	0.003 (4)	0.006 (4)	−0.003 (4)
C9	0.066 (6)	0.063 (6)	0.045 (4)	0.018 (5)	0.023 (4)	0.009 (4)
C10	0.059 (6)	0.043 (5)	0.053 (5)	0.021 (5)	0.018 (4)	0.011 (4)
C11	0.044 (5)	0.037 (5)	0.054 (5)	0.013 (4)	0.021 (4)	0.002 (4)
O1	0.052 (5)	0.047 (4)	0.040 (3)	0.010 (3)	0.015 (3)	0.006 (3)
C58	0.045 (12)	0.043 (12)	0.052 (13)	0.003 (6)	0.007 (7)	−0.002 (6)
C59	0.037 (6)	0.037 (6)	0.034 (5)	0.003 (5)	−0.002 (4)	0.000 (5)
C60	0.051 (8)	0.044 (8)	0.054 (7)	0.009 (6)	0.020 (5)	−0.002 (5)
C61	0.041 (6)	0.039 (6)	0.052 (6)	0.001 (5)	−0.001 (4)	0.005 (5)
O51	0.043 (5)	0.043 (5)	0.040 (4)	−0.001 (4)	0.008 (3)	−0.004 (4)
C12	0.038 (2)	0.038 (2)	0.0291 (17)	−0.0003 (16)	0.0128 (16)	0.0011 (15)
C13	0.045 (2)	0.0337 (19)	0.0262 (17)	−0.0008 (17)	0.0119 (17)	−0.0013 (16)
C14	0.054 (2)	0.040 (2)	0.0299 (19)	0.0019 (19)	0.0041 (18)	0.0034 (17)
C15	0.053 (3)	0.055 (3)	0.033 (2)	−0.001 (2)	−0.0035 (19)	−0.0038 (19)
C16	0.074 (3)	0.045 (3)	0.044 (2)	−0.015 (2)	−0.003 (2)	−0.008 (2)
O2	0.068 (2)	0.0327 (15)	0.0434 (15)	−0.0012 (14)	−0.0047 (15)	−0.0011 (12)

Geometric parameters (Å, º)

OW—HWA	0.82 (5)	C10—C11	1.333 (13)
OW—HWB	0.90 (7)	C10—H10	0.95
C1—C2	1.380 (5)	C11—O1	1.383 (12)
C1—C6	1.389 (5)	C11—H11	0.95
C1—N1	1.401 (4)	C58—C59	1.34 (2)
C2—C3	1.391 (5)	C58—O51	1.38 (2)
C2—N2	1.391 (5)	C59—C60	1.395 (19)
C3—C4	1.378 (6)	C59—H59	0.95
C3—H3	0.95	C60—C61	1.379 (18)
C4—C5	1.403 (6)	C60—H60	0.95
C4—H4	0.95	C61—O51	1.386 (16)
C5—C6	1.379 (6)	C61—H61	0.95
C5—H5	0.95	C12—C13	1.489 (5)
C6—H6	0.95	C12—H12A	0.99
N1—C7	1.350 (5)	C12—H12B	0.99
N1—C12	1.476 (4)	C13—C14	1.335 (5)
N2—C7	1.328 (5)	C13—O2	1.363 (4)
N2—H2	0.92 (6)	C14—C15	1.428 (6)
C7—C58	1.41 (2)	C14—H14	0.95
C7—C8	1.447 (13)	C15—C16	1.330 (6)
C8—C9	1.34 (2)	C15—H15	0.95
C8—O1	1.363 (19)	C16—O2	1.375 (5)
C9—C10	1.395 (13)	C16—H16	0.95
C9—H9	0.95
HWA—OW—HWB	109 (5)	C9—C10—H10	125.4
C2—C1—C6	122.2 (3)	C10—C11—O1	107.6 (10)
C2—C1—N1	106.9 (3)	C10—C11—H11	126.2
C6—C1—N1	130.9 (3)	O1—C11—H11	126.2
C1—C2—C3	121.8 (3)	C8—O1—C11	107.0 (10)
C1—C2—N2	107.0 (3)	C59—C58—O51	110.2 (16)
C3—C2—N2	131.3 (3)	C59—C58—C7	130 (2)
C4—C3—C2	116.5 (4)	O51—C58—C7	118.9 (19)
C4—C3—H3	121.7	C58—C59—C60	106.4 (16)
C2—C3—H3	121.7	C58—C59—H59	126.8
C3—C4—C5	121.5 (3)	C60—C59—H59	126.8
C3—C4—H4	119.2	C61—C60—C59	109.0 (16)
C5—C4—H4	119.2	C61—C60—H60	125.5
C6—C5—C4	121.9 (4)	C59—C60—H60	125.5
C6—C5—H5	119.1	C60—C61—O51	106.0 (14)
C4—C5—H5	119.1	C60—C61—H61	127.0
C5—C6—C1	116.1 (4)	O51—C61—H61	127.0
C5—C6—H6	121.9	C58—O51—C61	107.0 (13)
C1—C6—H6	121.9	N1—C12—C13	111.4 (3)
C7—N1—C1	107.5 (3)	N1—C12—H12A	109.4
C7—N1—C12	129.0 (3)	C13—C12—H12A	109.4
C1—N1—C12	123.4 (3)	N1—C12—H12B	109.4
C7—N2—C2	108.7 (3)	C13—C12—H12B	109.4
C7—N2—H2	122 (4)	H12A—C12—H12B	108.0
C2—N2—H2	129 (4)	C14—C13—O2	110.4 (3)
N2—C7—N1	109.9 (3)	C14—C13—C12	133.6 (4)
N2—C7—C58	125.9 (14)	O2—C13—C12	116.0 (3)
N1—C7—C58	124.1 (15)	C13—C14—C15	106.4 (4)
N2—C7—C8	120.0 (9)	C13—C14—H14	126.8
N1—C7—C8	130.1 (9)	C15—C14—H14	126.8
C9—C8—O1	109.8 (10)	C16—C15—C14	106.9 (4)
C9—C8—C7	129.7 (16)	C16—C15—H15	126.6
O1—C8—C7	120.5 (15)	C14—C15—H15	126.6
C8—C9—C10	106.0 (11)	C15—C16—O2	110.0 (4)
C8—C9—H9	127.0	C15—C16—H16	125.0
C10—C9—H9	127.0	O2—C16—H16	125.0
C11—C10—C9	109.3 (10)	C13—O2—C16	106.3 (3)
C11—C10—H10	125.4
C6—C1—C2—C3	−1.0 (5)	O1—C8—C9—C10	0 (2)
N1—C1—C2—C3	178.8 (3)	C7—C8—C9—C10	−177 (2)
C6—C1—C2—N2	−179.9 (3)	C8—C9—C10—C11	−2.9 (19)
N1—C1—C2—N2	0.0 (4)	C9—C10—C11—O1	5.0 (16)
C1—C2—C3—C4	0.1 (5)	C9—C8—O1—C11	3 (2)
N2—C2—C3—C4	178.6 (4)	C7—C8—O1—C11	−179.4 (18)
C2—C3—C4—C5	0.7 (6)	C10—C11—O1—C8	−5.2 (19)
C3—C4—C5—C6	−0.5 (7)	N2—C7—C58—C59	−146 (4)
C4—C5—C6—C1	−0.5 (6)	N1—C7—C58—C59	34 (6)
C2—C1—C6—C5	1.2 (6)	C8—C7—C58—C59	−140.30
N1—C1—C6—C5	−178.6 (4)	N2—C7—C58—O51	25 (5)
C2—C1—N1—C7	−0.5 (4)	N1—C7—C58—O51	−155 (3)
C6—C1—N1—C7	179.3 (4)	C8—C7—C58—O51	30.30
C2—C1—N1—C12	−177.5 (3)	O51—C58—C59—C60	1 (4)
C6—C1—N1—C12	2.3 (6)	C7—C58—C59—C60	173 (4)
C1—C2—N2—C7	0.5 (4)	C58—C59—C60—C61	6 (3)
C3—C2—N2—C7	−178.2 (4)	C59—C60—C61—O51	−11 (2)
C2—N2—C7—N1	−0.9 (4)	C59—C58—O51—C61	−8 (4)
C2—N2—C7—C58	179 (3)	C7—C58—O51—C61	179 (3)
C2—N2—C7—C8	178.6 (13)	C60—C61—O51—C58	11 (3)
C1—N1—C7—N2	0.8 (4)	C7—N1—C12—C13	−99.5 (4)
C12—N1—C7—N2	177.6 (3)	C1—N1—C12—C13	76.9 (4)
C1—N1—C7—C58	−179 (2)	N1—C12—C13—C14	−108.2 (5)
C12—N1—C7—C58	−3 (3)	N1—C12—C13—O2	70.0 (4)
C1—N1—C7—C8	−178.5 (15)	O2—C13—C14—C15	0.3 (4)
C12—N1—C7—C8	−1.7 (16)	C12—C13—C14—C15	178.6 (4)
N2—C7—C8—C9	−1 (3)	C13—C14—C15—C16	−1.0 (5)
N1—C7—C8—C9	177.9 (19)	C14—C15—C16—O2	1.3 (6)
C58—C7—C8—C9	−180.30	C14—C13—O2—C16	0.5 (4)
N2—C7—C8—O1	−178.0 (15)	C12—C13—O2—C16	−178.2 (3)
N1—C7—C8—O1	1 (3)	C15—C16—O2—C13	−1.1 (5)
C58—C7—C8—O1	10.30

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
OW—HWA···Cl1	0.82 (5)	2.24 (5)	3.066 (4)	178 (5)
OW—HWB···Cl1^i	0.90 (7)	2.18 (7)	3.068 (4)	169 (5)
N2—H2···OW	0.92 (6)	1.72 (6)	2.628 (4)	170 (6)

Symmetry code: (i) x−1, y, z.

(III) 2-(Furan-2-yl)-1-[(furan-2-yl)methyl]-1H-benzimidazol-3-ium bromide

Crystal data

C18H17N2O2^+·Br^−	Z = 2
Mr = 373.24	F(000) = 380
Triclinic, P1	Dx = 1.509 Mg m^−3
a = 9.1903 (10) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.619 (1) Å	Cell parameters from 5609 reflections
c = 9.7443 (11) Å	θ = 2.3–25.1°
α = 93.132 (3)°	µ = 2.51 mm^−1
β = 101.859 (3)°	T = 200 K
γ = 101.684 (3)°	Block, clear colourless
V = 821.38 (16) Å^3	0.50 × 0.40 × 0.30 mm

Data collection

Bruker SMART X2S benchtop diffractometer	2915 independent reflections
Radiation source: sealed microfocus tube	2374 reflections with I > 2σ(I)
Doubly curved silicon crystal monochromator	Rint = 0.043
Detector resolution: 8.3330 pixels mm^-1	θmax = 25.3°, θmin = 2.8°
ω scans	h = −11→10
Absorption correction: multi-scan (SADABS; Bruker, 2013)	k = −11→11
Tmin = 0.35, Tmax = 0.52	l = −11→11
9745 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.028	Hydrogen site location: mixed
wR(F^2) = 0.063	H atoms treated by a mixture of independent and constrained refinement
S = 0.96	w = 1/[σ^2(Fo^2) + (0.031P)^2] where P = (Fo^2 + 2Fc^2)/3
2915 reflections	(Δ/σ)max < 0.001
230 parameters	Δρmax = 0.42 e Å^−3
60 restraints	Δρmin = −0.36 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Br1	−0.45113 (3)	0.72114 (3)	−0.16112 (3)	0.03975 (11)
C1	0.0686 (3)	0.9254 (3)	0.1692 (2)	0.0323 (6)
C2	−0.0871 (3)	0.8790 (3)	0.1222 (2)	0.0343 (6)
C3	−0.1870 (3)	0.9395 (3)	0.1830 (3)	0.0381 (6)
H3	−0.294	0.9076	0.1499	0.046*
C4	−0.1283 (3)	1.0461 (3)	0.2918 (3)	0.0395 (6)
C5	0.0321 (3)	1.0948 (3)	0.3390 (2)	0.0375 (6)
C6	0.1314 (3)	1.0349 (2)	0.2784 (2)	0.0334 (6)
H6	0.2386	1.067	0.3099	0.04*
C41	−0.2351 (3)	1.1085 (3)	0.3622 (3)	0.0561 (8)
H41A	−0.3404	1.059	0.3201	0.084*
H41B	−0.2224	1.2102	0.3492	0.084*
H41C	−0.212	1.0968	0.4631	0.084*
C51	0.0955 (3)	1.2117 (3)	0.4575 (3)	0.0525 (7)
H51A	0.2066	1.2385	0.4709	0.079*
H51B	0.0693	1.1781	0.5443	0.079*
H51C	0.0521	1.2948	0.4346	0.079*
N1	0.1365 (2)	0.8433 (2)	0.08661 (19)	0.0291 (4)
N2	−0.1107 (2)	0.7715 (2)	0.0146 (2)	0.0325 (5)
H2	−0.196 (3)	0.732 (3)	−0.038 (3)	0.053 (9)*
C7	0.0234 (3)	0.7504 (3)	−0.0045 (2)	0.0327 (6)
C8	0.0324 (18)	0.646 (5)	−0.104 (6)	0.0340 (12)	0.608 (9)
C9	−0.0760 (10)	0.5518 (13)	−0.1971 (13)	0.0369 (17)	0.608 (9)
H9	−0.1826	0.5457	−0.2113	0.044*	0.608 (9)
C10	−0.0061 (9)	0.4639 (7)	−0.2696 (7)	0.0423 (18)	0.608 (9)
H10	−0.0536	0.3887	−0.3421	0.051*	0.608 (9)
C11	0.1434 (9)	0.5106 (7)	−0.2131 (8)	0.0432 (14)	0.608 (9)
H11	0.2206	0.471	−0.2414	0.052*	0.608 (9)
O1	0.1724 (6)	0.6211 (5)	−0.1104 (5)	0.0436 (12)	0.608 (9)
C80	0.038 (3)	0.637 (8)	−0.108 (9)	0.0340 (12)	0.392 (9)
C90	0.1551 (15)	0.5888 (16)	−0.1413 (14)	0.0369 (17)	0.392 (9)
H90	0.2603	0.6237	−0.1003	0.044*	0.392 (9)
C100	0.0914 (14)	0.4766 (11)	−0.2488 (11)	0.0423 (18)	0.392 (9)
H100	0.1449	0.4201	−0.2941	0.051*	0.392 (9)
C110	−0.0588 (14)	0.4651 (14)	−0.2748 (15)	0.0432 (14)	0.392 (9)
H110	−0.1295	0.3972	−0.3438	0.052*	0.392 (9)
O100	−0.0994 (10)	0.5620 (15)	−0.1910 (15)	0.0436 (12)	0.392 (9)
C12	0.3037 (2)	0.8655 (3)	0.1013 (2)	0.0328 (6)
H12A	0.3504	0.9683	0.1259	0.039*
H12B	0.3249	0.8365	0.0097	0.039*
C13	0.3753 (2)	0.7831 (3)	0.2112 (2)	0.0322 (6)
C14	0.4401 (3)	0.6718 (3)	0.2068 (3)	0.0401 (6)
H14	0.4527	0.6216	0.1248	0.048*
C15	0.4869 (3)	0.6425 (3)	0.3486 (3)	0.0485 (7)
H15	0.5367	0.5687	0.3796	0.058*
C16	0.4478 (3)	0.7376 (3)	0.4292 (3)	0.0536 (8)
H16	0.4655	0.7425	0.529	0.064*
O2	0.3781 (2)	0.8282 (2)	0.34799 (18)	0.0497 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.02943 (14)	0.05026 (19)	0.03929 (16)	0.00953 (11)	0.00565 (11)	0.00671 (12)
C1	0.0347 (13)	0.0352 (15)	0.0328 (14)	0.0118 (11)	0.0137 (11)	0.0137 (12)
C2	0.0359 (13)	0.0415 (16)	0.0287 (13)	0.0129 (12)	0.0074 (11)	0.0138 (12)
C3	0.0340 (13)	0.0568 (19)	0.0322 (14)	0.0238 (13)	0.0100 (11)	0.0174 (14)
C4	0.0460 (15)	0.0521 (18)	0.0322 (14)	0.0263 (13)	0.0158 (12)	0.0196 (14)
C5	0.0491 (15)	0.0403 (16)	0.0288 (14)	0.0168 (13)	0.0118 (12)	0.0145 (12)
C6	0.0350 (13)	0.0345 (15)	0.0320 (14)	0.0081 (11)	0.0086 (11)	0.0077 (12)
C41	0.0598 (18)	0.079 (2)	0.0457 (17)	0.0405 (17)	0.0216 (15)	0.0137 (16)
C51	0.0652 (19)	0.0507 (19)	0.0482 (17)	0.0225 (15)	0.0184 (15)	0.0035 (15)
N1	0.0270 (10)	0.0337 (12)	0.0272 (11)	0.0072 (9)	0.0062 (9)	0.0066 (9)
N2	0.0243 (11)	0.0449 (14)	0.0277 (11)	0.0083 (10)	0.0033 (9)	0.0062 (10)
C7	0.0366 (13)	0.0369 (15)	0.0268 (13)	0.0101 (11)	0.0081 (11)	0.0113 (12)
C8	0.0400 (18)	0.033 (5)	0.032 (3)	0.0082 (19)	0.010 (2)	0.010 (2)
C9	0.024 (3)	0.043 (4)	0.041 (3)	0.003 (2)	0.002 (2)	0.009 (3)
C10	0.047 (5)	0.040 (2)	0.036 (2)	0.004 (4)	0.006 (4)	−0.0031 (18)
C11	0.045 (4)	0.042 (3)	0.043 (3)	0.009 (2)	0.015 (3)	−0.005 (2)
O1	0.034 (2)	0.048 (3)	0.048 (2)	0.0078 (17)	0.0115 (17)	−0.0059 (16)
C80	0.0400 (18)	0.033 (5)	0.032 (3)	0.0082 (19)	0.010 (2)	0.010 (2)
C90	0.024 (3)	0.043 (4)	0.041 (3)	0.003 (2)	0.002 (2)	0.009 (3)
C100	0.047 (5)	0.040 (2)	0.036 (2)	0.004 (4)	0.006 (4)	−0.0031 (18)
C110	0.045 (4)	0.042 (3)	0.043 (3)	0.009 (2)	0.015 (3)	−0.005 (2)
O100	0.034 (2)	0.048 (3)	0.048 (2)	0.0078 (17)	0.0115 (17)	−0.0059 (16)
C12	0.0253 (12)	0.0394 (15)	0.0339 (14)	0.0040 (11)	0.0100 (11)	0.0052 (12)
C13	0.0260 (12)	0.0419 (16)	0.0280 (13)	0.0070 (11)	0.0058 (10)	−0.0001 (12)
C14	0.0397 (14)	0.0473 (17)	0.0350 (15)	0.0157 (13)	0.0067 (12)	0.0015 (13)
C15	0.0437 (15)	0.059 (2)	0.0469 (17)	0.0229 (14)	0.0053 (14)	0.0119 (15)
C16	0.0535 (17)	0.081 (2)	0.0333 (15)	0.0348 (17)	0.0047 (14)	0.0123 (16)
O2	0.0548 (11)	0.0684 (13)	0.0329 (10)	0.0340 (10)	0.0060 (9)	0.0014 (10)

Geometric parameters (Å, º)

C1—C2	1.380 (3)	C9—C10	1.403 (10)
C1—C6	1.397 (3)	C9—H9	0.95
C1—N1	1.413 (3)	C10—C11	1.344 (7)
C2—N2	1.383 (3)	C10—H10	0.95
C2—C3	1.391 (3)	C11—O1	1.364 (8)
C3—C4	1.374 (4)	C11—H11	0.95
C3—H3	0.95	C80—C90	1.342 (16)
C4—C5	1.423 (3)	C80—O100	1.389 (17)
C4—C41	1.504 (3)	C90—C100	1.405 (12)
C5—C6	1.382 (3)	C90—H90	0.95
C5—C51	1.501 (4)	C100—C110	1.332 (10)
C6—H6	0.95	C100—H100	0.95
C41—H41A	0.98	C110—O100	1.362 (13)
C41—H41B	0.98	C110—H110	0.95
C41—H41C	0.98	C12—C13	1.491 (3)
C51—H51A	0.98	C12—H12A	0.99
C51—H51B	0.98	C12—H12B	0.99
C51—H51C	0.98	C13—C14	1.329 (3)
N1—C7	1.351 (3)	C13—O2	1.372 (3)
N1—C12	1.483 (3)	C14—C15	1.422 (3)
N2—C7	1.337 (3)	C14—H14	0.95
N2—H2	0.84 (3)	C15—C16	1.324 (4)
C7—C8	1.384 (10)	C15—H15	0.95
C7—C80	1.488 (15)	C16—O2	1.375 (3)
C8—C9	1.345 (12)	C16—H16	0.95
C8—O1	1.368 (12)
C2—C1—C6	121.4 (2)	O1—C8—C7	118.8 (11)
C2—C1—N1	106.8 (2)	C8—C9—C10	109.0 (7)
C6—C1—N1	131.8 (2)	C8—C9—H9	125.5
C1—C2—N2	106.8 (2)	C10—C9—H9	125.5
C1—C2—C3	120.9 (2)	C11—C10—C9	104.1 (7)
N2—C2—C3	132.3 (2)	C11—C10—H10	127.9
C4—C3—C2	118.9 (2)	C9—C10—H10	127.9
C4—C3—H3	120.5	C10—C11—O1	112.6 (6)
C2—C3—H3	120.5	C10—C11—H11	123.7
C3—C4—C5	120.1 (2)	O1—C11—H11	123.7
C3—C4—C41	119.4 (2)	C11—O1—C8	105.0 (6)
C5—C4—C41	120.4 (3)	C90—C80—O100	110.6 (11)
C6—C5—C4	121.0 (2)	C90—C80—C7	135.3 (17)
C6—C5—C51	119.2 (2)	O100—C80—C7	114.1 (16)
C4—C5—C51	119.9 (2)	C80—C90—C100	106.7 (10)
C5—C6—C1	117.7 (2)	C80—C90—H90	126.6
C5—C6—H6	121.1	C100—C90—H90	126.6
C1—C6—H6	121.1	C110—C100—C90	106.4 (12)
C4—C41—H41A	109.5	C110—C100—H100	126.8
C4—C41—H41B	109.5	C90—C100—H100	126.8
H41A—C41—H41B	109.5	C100—C110—O100	112.3 (12)
C4—C41—H41C	109.5	C100—C110—H110	123.9
H41A—C41—H41C	109.5	O100—C110—H110	123.9
H41B—C41—H41C	109.5	C110—O100—C80	103.9 (10)
C5—C51—H51A	109.5	N1—C12—C13	112.61 (17)
C5—C51—H51B	109.5	N1—C12—H12A	109.1
H51A—C51—H51B	109.5	C13—C12—H12A	109.1
C5—C51—H51C	109.5	N1—C12—H12B	109.1
H51A—C51—H51C	109.5	C13—C12—H12B	109.1
H51B—C51—H51C	109.5	H12A—C12—H12B	107.8
C7—N1—C1	107.74 (19)	C14—C13—O2	110.5 (2)
C7—N1—C12	129.1 (2)	C14—C13—C12	133.6 (2)
C1—N1—C12	123.12 (19)	O2—C13—C12	115.9 (2)
C7—N2—C2	109.6 (2)	C13—C14—C15	106.6 (2)
C7—N2—H2	124.6 (19)	C13—C14—H14	126.7
C2—N2—H2	125.3 (19)	C15—C14—H14	126.7
N2—C7—N1	109.0 (2)	C16—C15—C14	106.9 (2)
N2—C7—C8	121.5 (7)	C16—C15—H15	126.5
N1—C7—C8	129.4 (7)	C14—C15—H15	126.5
N2—C7—C80	123.4 (10)	C15—C16—O2	110.5 (2)
N1—C7—C80	127.6 (9)	C15—C16—H16	124.8
C9—C8—O1	109.3 (7)	O2—C16—H16	124.8
C9—C8—C7	131.7 (12)	C13—O2—C16	105.5 (2)
C6—C1—C2—N2	179.83 (19)	N2—C7—C8—O1	−174 (3)
N1—C1—C2—N2	0.2 (2)	N1—C7—C8—O1	5 (8)
C6—C1—C2—C3	−0.4 (3)	C80—C7—C8—O1	−30.100
N1—C1—C2—C3	179.99 (19)	O1—C8—C9—C10	−1 (6)
C1—C2—C3—C4	−0.5 (3)	C7—C8—C9—C10	−177 (6)
N2—C2—C3—C4	179.3 (2)	C8—C9—C10—C11	1 (3)
C2—C3—C4—C5	1.1 (3)	C9—C10—C11—O1	0.1 (8)
C2—C3—C4—C41	−177.6 (2)	C10—C11—O1—C8	−1 (3)
C3—C4—C5—C6	−1.0 (3)	C9—C8—O1—C11	1 (5)
C41—C4—C5—C6	177.7 (2)	C7—C8—O1—C11	178 (4)
C3—C4—C5—C51	179.8 (2)	N2—C7—C80—C90	−175 (9)
C41—C4—C5—C51	−1.5 (3)	N1—C7—C80—C90	2 (15)
C4—C5—C6—C1	0.2 (3)	C8—C7—C80—C90	150.100
C51—C5—C6—C1	179.4 (2)	N2—C7—C80—O100	5 (10)
C2—C1—C6—C5	0.5 (3)	N1—C7—C80—O100	−178 (4)
N1—C1—C6—C5	−180.0 (2)	C8—C7—C80—O100	−30.100
C2—C1—N1—C7	−0.8 (2)	O100—C80—C90—C100	−1 (9)
C6—C1—N1—C7	179.6 (2)	C7—C80—C90—C100	179 (10)
C2—C1—N1—C12	177.46 (17)	C80—C90—C100—C110	1 (5)
C6—C1—N1—C12	−2.1 (3)	C90—C100—C110—O100	−0.3 (15)
C1—C2—N2—C7	0.5 (2)	C100—C110—O100—C80	0 (5)
C3—C2—N2—C7	−179.3 (2)	C90—C80—O100—C110	1 (9)
C2—N2—C7—N1	−1.0 (2)	C7—C80—O100—C110	−179 (6)
C2—N2—C7—C8	179 (4)	C7—N1—C12—C13	−94.9 (3)
C2—N2—C7—C80	177 (5)	C1—N1—C12—C13	87.2 (2)
C1—N1—C7—N2	1.1 (2)	N1—C12—C13—C14	110.9 (3)
C12—N1—C7—N2	−177.01 (18)	N1—C12—C13—O2	−69.4 (3)
C1—N1—C7—C8	−178 (4)	O2—C13—C14—C15	0.3 (3)
C12—N1—C7—C8	4 (4)	C12—C13—C14—C15	−179.9 (2)
C1—N1—C7—C80	−177 (6)	C13—C14—C15—C16	−0.1 (3)
C12—N1—C7—C80	5 (6)	C14—C15—C16—O2	−0.1 (3)
N2—C7—C8—C9	1 (9)	C14—C13—O2—C16	−0.4 (3)
N1—C7—C8—C9	−180 (5)	C12—C13—O2—C16	179.81 (19)
C80—C7—C8—C9	140.100	C15—C16—O2—C13	0.3 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···Br1	0.84 (3)	2.38 (3)	3.170 (2)	155 (2)