The hydrogen-bonding patterns of 3-phenyl­propyl­ammonium benzoate and 3-phenyl­propyl­ammonium 3-iodo­benzoate: generation of chiral crystals from achiral mol­ecules

The crystal structures and hydrogen-bonding patterns of 3-phenyl­propyl­ammonium benzoate, C₉H₁₄N⁺·C₇H₅O₂⁻, (I), and 3-phenyl­propyl­ammonium 3-iodo­benzoate, C₉H₁₄N⁺·C₇H₄IO₂⁻, (II), are reported and compared. The addition of the I atom on the anion in (II) produces a different hydrogen-bonding pattern to that of (I). In addition, the supra­molecular heterosynthon of (II) produces a chiral crystal packing not observed in (I). Compound (I) packs in a centrosymmetric fashion and forms achiral one-dimensional hydrogen-bonded columns through charge-assisted N—H...O hydrogen bonds. Compound (II) packs in a chiral space group and forms helical one-dimensional hydrogen-bonded columns with 2₁ symmetry, consisting of repeating R₄³(10) hydrogen-bonded rings that are commonly observed in ammonium carboxyl­ate salts con­tain­ing chiral mol­ecules. This hydrogen-bond pattern, which has been observed repeatedly in ammonium carboxyl­ate salts, thus provides a means of producing chiral crystal structures from achiral mol­ecules.

S1. Comment

Supramolecular heterosynthons are defined as intermolecular interactions that exist between different but compatible functional groups (Walsh et al., 2003; Bis & Zaworotko, 2005; Bis et al., 2006). If one wishes to combine two or more molecules in the solid state, heterosynthons increase the number of possible combinations when compared to homosynthons, which only occur between the same functional group. Examples of neutral heterosynthons are the carboxylic acid–pyridine and carboxylic acid–amide dimers (Aakerōy & Schultheiss, 2007).

One of the aims of supramolecular chemistry is to identify and exploit those heterosynthons that behave predictably in the solid state. Desiraju and others have called the phenomenon of predictability `synthon robustness', with respect to those synthons that occur repeatedly in crystal structures (Banerjee, Mondal et al., 2006). If the intermolecular interaction is between charged species, the electrostatic attractive force strengthens the heterosynthon and a greater robustness is expected (Banerjee, Saha et al., 2006). Robustness of a heterosynthon refers to how a desired synthon changes under the influence of steric or electronic effects of functional groups on the molecules interacting in the crystal structures. To this end, we have investigated the heterosynthon formed between carboxylic acids and amines. More specifically, the compounds we have used all transfer the carboxylic acid proton to the amine to form ammonium carboxylate salts (Lemmerer et al., 2008a,b,c).

A data analysis of (R—NH₃⁺).(R'—CO₂^-) ammonium carboxylate salt structures in the Cambridge Structural Database (CSD, Ver. 5.29, November 2007 release; Allen, 2002) revealed the three most frequently occurring heterosynthons described using graph set notation (Bernstein et al., 1995): one-dimensional columns of R³₄(10) hydrogen-bonded rings (75/126), one-dimensional columns of alternating R²₄(8) and R⁴₄(12) hydrogen-bonded rings (26/126) and two-dimensional layers built up with R⁵₆(16) hydrogen-bonded rings (19/126) (Lemmerer et al., 2008b). The one-dimensional columns of R³₄(10) rings are also called type-II columns by Kinbara et al. (1996) and are shown schematically in Fig. 1. In fact, this motif occurs even more frequently with increasing robustness if the cation containing the ammonium group is chiral, such as 1-phenylethylammonium. In those ammonium carboxylate salts, the type-II heterosynthon is formed in 69 out of 83 structures located in the CSD. This paper describes an attempt to determine if the type-II motif occurs in a related salt using achiral 3-phenylpropylammonium as the cation and benzoate and 3-iodobenzoate as the anion.

The molecular structure and atomic numbering scheme of (I) are shown in Fig. 2(a). The asymmetric unit consists of one 3-phenylpropylammonium cation and one benzoate anion. The propylammonium chain is parallel to the aromatic ring, with the mean deviation of a least-squares plane less than 0.209 (1) Å. The ammonium group forms three charge-assisted N—H···O hydrogen bonds to the benzoate group. H atoms H1A and H1B form a 12-membered hydrogen-bonded ring, R⁴₄(12), connecting two cations and two anions. This ring is parallel to the ab plane. Adjacent R⁴₄(12) rings are joined through a hydrogen bond from H1C to O2 in the direction of the crystallographic c axis (Fig. 3). This means that O2 functions as a bifurcated hydrogen-bond acceptor. Ultimately, this results in one-dimensional hydrogen-bonded columns made up of four cations and four anions. Compound (I) does not form the type-II column. Adjacent columns are connected via a C—H···π interaction from the cation of adjacent columns (C14—H14A···Cg; d = 2.64 Å, D = 3.563 (2) Å, θ = 155°) [Cg is the centroid of the benzoate ring C1–C6 at (1-x,1-y,1-z)].

The molecular structure and atomic numbering scheme of the asymmetric unit of (II) are shown in Fig. 2(b). The molecular geometries of the propylammonium cation and 3-iodobenzoate anion are similar to (I). The ammonium group forms three charge-asisted hydrogen bonds to form a ring, graph set notation R³₄(10), consisting of two ammonium cations and two carboxylate anions, one involving both O atoms, O1 and O2, and the second involving only the O1 atom (see Fig. 1). This hydrogen-bonded pattern has translational symmetry via a twofold screw axis inherent in the space group and is repeated along the a axis [6.9616 (2) Å]. All three ammonium H atoms are used to form the ring and O2 acts as a bifurcated hydrogen-bond acceptor. Compound (II) thus forms the type-II hydrogen-bonded column with two cations and two anions (Fig. 4). The columns are connected by a pair of C—H···π interactions through both H atoms on the benzylic position to the aromatic ring of adjacent cations [C14A—H14A···Cgⁱ: d = 2.73 Å, D = 3.550 (3) Å, θ = 141°; C14B—H14B···Cgⁱⁱ: d = 2.70 Å, D =3.522 (3) Å, θ = 141°] (Fig. 5) [Cgⁱ and Cgⁱⁱ are the centroids of the m-iodobenzoate ring C1–C6 at (1/2+x,1/2-y,1-z) and at (-1/2+x,1/2-y,1-z), respectively]. Adjacent columns are further stabilized by a C3—I1···O1ⁱⁱⁱ [iii is equivalent position (1-x,1/2+y,3/2-z)] halogen bond (Ramasubbu et al., 1986; Corradi et al., 2000; Aakerōy et al., 2007) with d(I1···O1) = 3.050 (2) Å, θ (C3—I1···O1) = 165.04 (8)° along the [011] and [01-1] directions to create a chicken-wire shaped mesh of columns (Fig. 5).

Both compounds (I) and (II) do not contain a cation or anion that is chiral and the type-II synthon is not formed in (I). However, the I atom attached to the anion in (II) causes the type-II column to be formed and crystallizes in the chiral spacegroup P2₁2₁2₁. In supramolecular chemistry, the creation of chiral crystals from constituents that do not possess a chirality centre is a much studied phenomenon (Mateos-Timoneda et al., 2004). Chiral helices are created when the molecules interact to create an arrangement with 2₁ symmetry (Tanaka et al., 2007). The type-II supramolecular heterosynthon of (II) is such a `helical' generating interaction (Koshima, 2000).

Related literature

For related literature, see: Aakerōy & Schultheiss (2007); Aakerōy et al., 2007; Allen (2002); Banerjee et al. (2006a, 2006b); Bernstein et al. (1995); Bis & Zaworotko (2005); Bis et al. (2006); Corradi et al., 2000; Kinbara et al. (1996); Koshima (2000); Lemmerer et al. (2008a, 2008b); Mateos-Timoneda, Crego-Calama & Reinhoudt (2004); Ramasubbu et al., 1986; Tanaka et al. (2007); Walsh et al. (2003).

S2. Experimental

All chemicals were purchased from commercial sources and used as received. (I) was prepared by slowly evaporating a solution of 3-phenylpropylamine (0.100 g, 0.704 mmol) and benzoic acid (0.0904 g, 0.704 mmol) dissolved in 5 ml methanol. (II) was prepared by slowly evaporating a solution of 3-phenylpropylamine (0.100 g, 0.704 mmol) and m-iodobenzoic acid (0.183 g, 0.704 mmol) in 10 ml methanol.

S3. Refinement

For all compounds, all C—H atoms were refined using a riding model, with a distance of 0.95 Å (Ar—H) and 0.99 Å (CH₂), and U_iso(H) = 1.2U_eq(C). N—H atoms on the ammonium group were located in the difference Fourier map and their coordinates refined freely with U_iso(H) =1.5U_eq(N).

Computing details

For both compounds, data collection: COLLECT (Nonius, 2000); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2003).

Figures

	Fig. 1. The type-II supramolecular heterosynthon that is commonly observed in ammonium carboxylate salts.
	Fig. 2. The asymmetric units of (a) (I) and (b) (II). Displacement ellipsoids are shown at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 3. The hydrogen-bonding pattern of (I). H atoms not involved in hydrogen bonding are omitted for clarity. Atoms marked with superscript i and ii are at the symmetry positions (-x+3/2, -y+1/2, z) and (-x+3/2, y, z+1/2) respectively.
	Fig. 4. The type II hydrogen bonding pattern of (II), generating a 21 helical pattern. H atoms not involved in hydrogen bonding are omitted for clarity. Atoms marked with the superscripts i and ii are at the symmetry positions (x-1/2, -y+3/2, -z+1) and (x+1/2, -y+3/2, -z+1), respectively.
	Fig. 5. The packing diagram of (I), showing the two C—H···π interactions and C—I···O halogen bonds that connect adjacent helical columns. H atoms not involved in hydrogen bonding are omitted for clarity. Atoms marked with the superscripts i, ii, iii and iv are at the symmetry positions (x+1/2, -y+1/2, -z+1), (x+1/2, -y+1/2, -z+1), (-x+1, y-1/2, -z+3/2) and (x, y-1, z), respectively.

(I) 3-phenylpropylammonium benzoate

Crystal data

C9H14N^+·C7H5O2^−	F(000) = 1104
Mr = 257.32	Dx = 1.214 Mg m^−3 Dm = 0 Mg m^−3 Dm measured by not measured
Orthorhombic, Pccn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ab 2ac	Cell parameters from 2678 reflections
a = 16.2963 (2) Å	θ = 2.5–27.2°
b = 23.3235 (5) Å	µ = 0.08 mm^−1
c = 7.4094 (7) Å	T = 173 K
V = 2816.2 (3) Å^3	Block, colourless
Z = 8	0.5 × 0.13 × 0.10 mm

Data collection

Nonius KappaCCD area-detector diffractometer	3401 independent reflections
Radiation source: fine-focus sealed tube	2087 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.107
0.8° ϕ and ω scans	θmax = 28°, θmin = 1.5°
Absorption correction: integration Bruker XPREP (Bruker, 1999)	h = −21→21
Tmin = 0.966, Tmax = 0.992	k = −30→27
16169 measured reflections	l = −9→9

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)] = 0.049	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.133	H atoms treated by a mixture of independent and constrained refinement
S = 0.92	w = 1/[σ^2(Fo^2) + (0.0693P)^2] where P = (Fo^2 + 2Fc^2)/3
3401 reflections	(Δ/σ)max < 0.001
181 parameters	Δρmax = 0.20 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

Experimental. Numerical integration absorption corrections based on indexed crystal faces were applied using the XPREP routine (Bruker, 2004)

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.

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

	x	y	z	Uiso*/Ueq
C1	0.99456 (8)	0.31588 (6)	0.3237 (2)	0.0301 (3)
C2	1.03846 (11)	0.28071 (7)	0.2094 (2)	0.0442 (4)
H2	1.0106	0.2533	0.1371	0.053*
C3	1.12350 (11)	0.28525 (9)	0.1996 (3)	0.0553 (5)
H3	1.1535	0.2608	0.1211	0.066*
C4	1.16402 (10)	0.32493 (8)	0.3033 (3)	0.0519 (5)
H4	1.222	0.3281	0.2959	0.062*
C5	1.12083 (9)	0.35996 (8)	0.4174 (3)	0.0432 (4)
H5	1.149	0.3873	0.4895	0.052*
C6	1.03601 (8)	0.35556 (6)	0.4280 (2)	0.0327 (4)
H6	1.0063	0.3799	0.5073	0.039*
C7	0.90259 (9)	0.31122 (7)	0.3358 (2)	0.0364 (4)
O1	0.86679 (7)	0.27816 (5)	0.22473 (17)	0.0495 (4)
O2	0.86628 (6)	0.33945 (6)	0.45306 (19)	0.0537 (4)
C8	0.46545 (8)	0.45621 (6)	0.3142 (2)	0.0291 (3)
C9	0.40954 (9)	0.42320 (7)	0.4095 (2)	0.0368 (4)
H9	0.4278	0.3902	0.473	0.044*
C10	0.32695 (9)	0.43799 (7)	0.4129 (3)	0.0452 (5)
H10	0.2894	0.4155	0.4807	0.054*
C11	0.29918 (10)	0.48494 (8)	0.3189 (2)	0.0473 (5)
H11	0.2425	0.4944	0.3196	0.057*
C12	0.35409 (10)	0.51819 (8)	0.2236 (2)	0.0469 (5)
H12	0.3354	0.5509	0.1591	0.056*
C13	0.43689 (9)	0.50383 (7)	0.2221 (2)	0.0379 (4)
H13	0.4745	0.5271	0.1569	0.046*
C14	0.55635 (8)	0.44305 (6)	0.3100 (2)	0.0298 (3)
H14A	0.5852	0.472	0.3843	0.036*
H14B	0.576	0.4474	0.1843	0.036*
C15	0.58070 (8)	0.38398 (6)	0.3765 (2)	0.0298 (3)
H15A	0.5631	0.3791	0.5035	0.036*
H15B	0.553	0.3543	0.3029	0.036*
C16	0.67285 (8)	0.37657 (6)	0.3632 (2)	0.0296 (3)
H16A	0.6909	0.3863	0.2394	0.036*
H16B	0.7	0.4034	0.4477	0.036*
N1	0.69841 (8)	0.31729 (5)	0.4060 (2)	0.0330 (3)
H1A	0.7596 (11)	0.3168 (7)	0.410 (2)	0.05*
H1B	0.6783 (10)	0.2894 (8)	0.313 (2)	0.05*
H1C	0.6771 (10)	0.3059 (8)	0.518 (3)	0.05*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0300 (7)	0.0292 (7)	0.0310 (9)	−0.0031 (6)	−0.0039 (6)	0.0047 (7)
C2	0.0531 (10)	0.0387 (9)	0.0409 (10)	0.0002 (8)	−0.0039 (8)	−0.0074 (8)
C3	0.0520 (11)	0.0578 (11)	0.0560 (12)	0.0174 (9)	0.0140 (9)	−0.0075 (10)
C4	0.0303 (8)	0.0628 (12)	0.0625 (13)	0.0045 (8)	0.0067 (8)	0.0016 (11)
C5	0.0302 (8)	0.0478 (9)	0.0517 (11)	−0.0079 (7)	0.0009 (7)	−0.0037 (9)
C6	0.0273 (7)	0.0338 (8)	0.0371 (9)	−0.0024 (6)	0.0020 (6)	−0.0021 (7)
C7	0.0305 (8)	0.0394 (9)	0.0392 (10)	−0.0077 (7)	−0.0079 (7)	0.0109 (8)
O1	0.0485 (7)	0.0482 (7)	0.0519 (8)	−0.0211 (5)	−0.0226 (6)	0.0121 (6)
O2	0.0244 (6)	0.0705 (9)	0.0663 (9)	−0.0034 (5)	0.0005 (6)	−0.0071 (8)
C8	0.0236 (7)	0.0322 (7)	0.0315 (8)	0.0017 (5)	−0.0028 (6)	−0.0064 (7)
C9	0.0247 (7)	0.0344 (8)	0.0512 (11)	−0.0007 (6)	−0.0002 (7)	0.0010 (8)
C10	0.0239 (7)	0.0476 (10)	0.0642 (13)	−0.0027 (7)	−0.0005 (7)	−0.0068 (9)
C11	0.0274 (8)	0.0572 (11)	0.0572 (12)	0.0105 (7)	−0.0083 (8)	−0.0127 (10)
C12	0.0450 (10)	0.0502 (10)	0.0457 (11)	0.0215 (8)	−0.0083 (8)	−0.0012 (9)
C13	0.0378 (8)	0.0402 (9)	0.0357 (9)	0.0072 (7)	−0.0001 (7)	0.0009 (8)
C14	0.0217 (6)	0.0341 (8)	0.0336 (9)	−0.0010 (5)	0.0000 (6)	−0.0013 (7)
C15	0.0206 (6)	0.0339 (7)	0.0348 (9)	−0.0004 (6)	0.0014 (6)	0.0025 (7)
C16	0.0204 (6)	0.0308 (7)	0.0376 (9)	−0.0008 (6)	0.0021 (6)	0.0008 (7)
N1	0.0243 (6)	0.0322 (7)	0.0425 (8)	0.0019 (5)	0.0077 (6)	−0.0005 (7)

Geometric parameters (Å, º)

C1—C2	1.379 (2)	C10—C11	1.375 (2)
C1—C6	1.382 (2)	C10—H10	0.95
C1—C7	1.5054 (19)	C11—C12	1.378 (2)
C2—C3	1.392 (2)	C11—H11	0.95
C2—H2	0.95	C12—C13	1.390 (2)
C3—C4	1.372 (3)	C12—H12	0.95
C3—H3	0.95	C13—H13	0.95
C4—C5	1.370 (2)	C14—C15	1.516 (2)
C4—H4	0.95	C14—H14A	0.99
C5—C6	1.3884 (19)	C14—H14B	0.99
C5—H5	0.95	C15—C16	1.5148 (17)
C6—H6	0.95	C15—H15A	0.99
C7—O2	1.241 (2)	C15—H15B	0.99
C7—O1	1.2695 (19)	C16—N1	1.4786 (18)
C8—C13	1.384 (2)	C16—H16A	0.99
C8—C9	1.386 (2)	C16—H16B	0.99
C8—C14	1.5131 (18)	N1—H1A	0.997 (18)
C9—C10	1.390 (2)	N1—H1B	1.005 (18)
C9—H9	0.95	N1—H1C	0.939 (19)
C2—C1—C6	119.22 (14)	C12—C11—H11	120.2
C2—C1—C7	120.65 (14)	C11—C12—C13	119.91 (16)
C6—C1—C7	120.12 (14)	C11—C12—H12	120
C1—C2—C3	120.20 (16)	C13—C12—H12	120
C1—C2—H2	119.9	C8—C13—C12	121.04 (15)
C3—C2—H2	119.9	C8—C13—H13	119.5
C4—C3—C2	120.10 (16)	C12—C13—H13	119.5
C4—C3—H3	119.9	C8—C14—C15	115.71 (12)
C2—C3—H3	119.9	C8—C14—H14A	108.4
C5—C4—C3	120.03 (16)	C15—C14—H14A	108.4
C5—C4—H4	120	C8—C14—H14B	108.4
C3—C4—H4	120	C15—C14—H14B	108.4
C4—C5—C6	120.12 (16)	H14A—C14—H14B	107.4
C4—C5—H5	119.9	C16—C15—C14	110.00 (11)
C6—C5—H5	119.9	C16—C15—H15A	109.7
C1—C6—C5	120.32 (14)	C14—C15—H15A	109.7
C1—C6—H6	119.8	C16—C15—H15B	109.7
C5—C6—H6	119.8	C14—C15—H15B	109.7
O2—C7—O1	123.86 (15)	H15A—C15—H15B	108.2
O2—C7—C1	118.56 (14)	N1—C16—C15	111.84 (12)
O1—C7—C1	117.58 (15)	N1—C16—H16A	109.2
C13—C8—C9	118.41 (13)	C15—C16—H16A	109.2
C13—C8—C14	118.80 (13)	N1—C16—H16B	109.2
C9—C8—C14	122.78 (13)	C15—C16—H16B	109.2
C8—C9—C10	120.54 (15)	H16A—C16—H16B	107.9
C8—C9—H9	119.7	C16—N1—H1A	107.5 (10)
C10—C9—H9	119.7	C16—N1—H1B	111.4 (10)
C11—C10—C9	120.49 (16)	H1A—N1—H1B	109.9 (13)
C11—C10—H10	119.8	C16—N1—H1C	110.5 (11)
C9—C10—H10	119.8	H1A—N1—H1C	109.8 (14)
C10—C11—C12	119.60 (15)	H1B—N1—H1C	107.7 (14)
C10—C11—H11	120.2
C6—C1—C2—C3	0.0 (2)	C13—C8—C9—C10	−0.4 (2)
C7—C1—C2—C3	−179.81 (15)	C14—C8—C9—C10	178.30 (15)
C1—C2—C3—C4	−0.3 (3)	C8—C9—C10—C11	1.3 (3)
C2—C3—C4—C5	0.4 (3)	C9—C10—C11—C12	−1.3 (3)
C3—C4—C5—C6	−0.3 (3)	C10—C11—C12—C13	0.5 (3)
C2—C1—C6—C5	0.1 (2)	C9—C8—C13—C12	−0.4 (2)
C7—C1—C6—C5	179.93 (14)	C14—C8—C13—C12	−179.20 (14)
C4—C5—C6—C1	0.0 (3)	C11—C12—C13—C8	0.4 (3)
C2—C1—C7—O2	172.78 (15)	C13—C8—C14—C15	−166.73 (14)
C6—C1—C7—O2	−7.1 (2)	C9—C8—C14—C15	14.6 (2)
C2—C1—C7—O1	−6.9 (2)	C8—C14—C15—C16	179.49 (12)
C6—C1—C7—O1	173.23 (14)	C14—C15—C16—N1	−173.21 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2	1.00 (2)	1.85 (2)	2.806 (2)	161 (2)
N1—H1B···O1^i	1.01 (2)	1.86 (2)	2.809 (2)	157 (2)
N1—H1C···O1^ii	0.94 (2)	1.81 (2)	2.746 (2)	175 (2)

Symmetry codes: (i) −x+3/2, −y+1/2, z; (ii) −x+3/2, y, z+1/2.

(II) 3-phenylpropylammonium 3-iodobenzoate

Crystal data

C9H14N^+·C7H4IO2^−	F(000) = 760
Mr = 383.21	Dx = 1.603 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 23461 reflections
a = 6.9616 (2) Å	θ = 0.4–28.3°
b = 12.8517 (3) Å	µ = 2.02 mm^−1
c = 17.7512 (3) Å	T = 173 K
V = 1588.17 (6) Å^3	Block, colourless
Z = 4	0.38 × 0.11 × 0.1 mm

Data collection

Nonius KappaCCD area-detector diffractometer	3826 independent reflections
Radiation source: fine-focus sealed tube	3554 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.044
0.8° ϕ and ω scans	θmax = 28°, θmin = 2.8°
Absorption correction: integration Bruker XPREP (Bruker, 1999)	h = −9→9
Tmin = 0.594, Tmax = 0.845	k = −16→16
22976 measured reflections	l = −23→21

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.023	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.051	w = 1/[σ^2(Fo^2) + (0.0219P)^2 + 0.5355P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max = 0.001
3826 reflections	Δρmax = 0.59 e Å^−3
190 parameters	Δρmin = −0.74 e Å^−3
0 restraints	Absolute structure: Flack (1983); 1625 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.023 (18)

Special details

Experimental. Numerical integration absorption corrections based on indexed crystal faces were applied using the XPREP routine (Bruker, 2004)

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.

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

	x	y	z	Uiso*/Ueq
C1	0.1344 (3)	0.94392 (19)	0.67079 (13)	0.0207 (5)
C2	0.2661 (3)	1.01649 (18)	0.69766 (14)	0.0222 (5)
H2	0.3968	1.0133	0.6825	0.027*
C3	0.2048 (4)	1.09372 (19)	0.74692 (14)	0.0236 (5)
C4	0.0139 (4)	1.0998 (2)	0.76971 (15)	0.0293 (6)
H4	−0.0275	1.1539	0.8023	0.035*
C5	−0.1143 (4)	1.0259 (2)	0.74415 (15)	0.0312 (6)
H5	−0.2441	1.0279	0.7606	0.037*
C6	−0.0554 (3)	0.9485 (2)	0.69468 (14)	0.0257 (5)
H6	−0.1454	0.8985	0.6771	0.031*
C7	0.2006 (4)	0.86126 (18)	0.61550 (14)	0.0221 (5)
O1	0.3768 (3)	0.84991 (14)	0.60588 (10)	0.0286 (4)
O2	0.0719 (2)	0.80881 (14)	0.58230 (10)	0.0300 (4)
I1	0.40354 (2)	1.200055 (13)	0.792448 (10)	0.03146 (6)
C8	0.2291 (4)	0.26298 (19)	0.48336 (14)	0.0221 (5)
C9	0.2343 (4)	0.2586 (2)	0.40536 (15)	0.0303 (6)
H9	0.2383	0.3214	0.3772	0.036*
C10	0.2336 (4)	0.1634 (2)	0.36767 (16)	0.0344 (6)
H10	0.2363	0.1618	0.3142	0.041*
C11	0.2289 (4)	0.0719 (2)	0.40755 (17)	0.0322 (6)
H11	0.2288	0.0071	0.3818	0.039*
C12	0.2242 (4)	0.0746 (2)	0.48556 (16)	0.0305 (6)
H12	0.2211	0.0116	0.5135	0.037*
C13	0.2243 (4)	0.1693 (2)	0.52254 (15)	0.0268 (6)
H13	0.2209	0.1704	0.576	0.032*
C14	0.2270 (4)	0.36355 (19)	0.52730 (15)	0.0242 (5)
H14A	0.3416	0.3649	0.5603	0.029*
H14B	0.1124	0.3636	0.5603	0.029*
C15	0.2251 (4)	0.46302 (18)	0.48080 (14)	0.0236 (5)
H15A	0.343	0.4664	0.4497	0.028*
H15B	0.1132	0.4622	0.4464	0.028*
C16	0.2143 (4)	0.55823 (19)	0.53091 (15)	0.0262 (5)
H16A	0.0987	0.5535	0.5632	0.031*
H16B	0.3284	0.5601	0.5642	0.031*
N1	0.2059 (4)	0.65606 (17)	0.48579 (13)	0.0228 (4)
H1A	0.185 (5)	0.712 (2)	0.5114 (18)	0.034*
H1B	0.109 (5)	0.655 (2)	0.4555 (18)	0.034*
H1C	0.307 (5)	0.667 (2)	0.4616 (19)	0.034*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0230 (13)	0.0194 (11)	0.0197 (11)	0.0049 (9)	−0.0013 (9)	0.0013 (9)
C2	0.0210 (11)	0.0225 (12)	0.0233 (13)	0.0020 (9)	0.0015 (10)	0.0025 (10)
C3	0.0282 (13)	0.0177 (12)	0.0249 (13)	−0.0019 (11)	−0.0018 (11)	−0.0019 (10)
C4	0.0321 (14)	0.0289 (14)	0.0269 (14)	0.0050 (12)	0.0024 (11)	−0.0046 (11)
C5	0.0221 (13)	0.0397 (16)	0.0319 (13)	0.0017 (13)	0.0007 (13)	−0.0047 (11)
C6	0.0235 (13)	0.0276 (13)	0.0260 (13)	0.0009 (10)	−0.0018 (10)	−0.0014 (10)
C7	0.0266 (13)	0.0171 (12)	0.0227 (12)	0.0045 (10)	0.0000 (11)	0.0022 (9)
O1	0.0227 (9)	0.0284 (9)	0.0348 (10)	0.0065 (8)	0.0045 (8)	−0.0023 (8)
O2	0.0270 (9)	0.0271 (9)	0.0358 (9)	0.0038 (9)	−0.0034 (8)	−0.0107 (8)
I1	0.03126 (8)	0.02426 (8)	0.03885 (9)	−0.00373 (8)	0.00276 (8)	−0.00771 (7)
C8	0.0188 (12)	0.0220 (12)	0.0254 (13)	0.0009 (10)	−0.0012 (10)	−0.0001 (10)
C9	0.0382 (16)	0.0252 (13)	0.0275 (14)	0.0056 (12)	−0.0003 (12)	−0.0013 (11)
C10	0.0427 (16)	0.0321 (15)	0.0284 (14)	0.0071 (13)	0.0014 (13)	−0.0052 (11)
C11	0.0307 (14)	0.0234 (14)	0.0425 (16)	0.0004 (11)	0.0019 (13)	−0.0069 (12)
C12	0.0275 (14)	0.0228 (13)	0.0413 (16)	0.0011 (11)	0.0009 (12)	0.0062 (11)
C13	0.0255 (13)	0.0263 (13)	0.0287 (13)	0.0021 (10)	0.0011 (11)	0.0025 (10)
C14	0.0250 (13)	0.0240 (13)	0.0234 (12)	0.0004 (10)	−0.0007 (10)	−0.0010 (10)
C15	0.0235 (12)	0.0200 (12)	0.0272 (13)	0.0006 (10)	0.0008 (11)	−0.0013 (10)
C16	0.0282 (13)	0.0228 (13)	0.0274 (13)	0.0001 (11)	−0.0008 (11)	−0.0022 (10)
N1	0.0210 (11)	0.0190 (10)	0.0283 (12)	−0.0009 (9)	0.0014 (10)	−0.0052 (9)

Geometric parameters (Å, º)

C1—C6	1.389 (4)	C10—C11	1.372 (4)
C1—C2	1.392 (3)	C10—H10	0.95
C1—C7	1.518 (3)	C11—C12	1.386 (4)
C2—C3	1.390 (4)	C11—H11	0.95
C2—H2	0.95	C12—C13	1.382 (4)
C3—C4	1.391 (4)	C12—H12	0.95
C3—I1	2.106 (3)	C13—H13	0.95
C4—C5	1.380 (4)	C14—C15	1.522 (3)
C4—H4	0.95	C14—H14A	0.99
C5—C6	1.388 (4)	C14—H14B	0.99
C5—H5	0.95	C15—C16	1.515 (3)
C6—H6	0.95	C15—H15A	0.99
C7—O1	1.247 (3)	C15—H15B	0.99
C7—O2	1.267 (3)	C16—N1	1.492 (3)
C8—C9	1.386 (4)	C16—H16A	0.99
C8—C13	1.391 (4)	C16—H16B	0.99
C8—C14	1.510 (3)	N1—H1A	0.86 (3)
C9—C10	1.395 (4)	N1—H1B	0.87 (4)
C9—H9	0.95	N1—H1C	0.84 (4)
C6—C1—C2	119.6 (2)	C12—C11—H11	120.2
C6—C1—C7	121.1 (2)	C13—C12—C11	119.8 (3)
C2—C1—C7	119.4 (2)	C13—C12—H12	120.1
C3—C2—C1	119.5 (2)	C11—C12—H12	120.1
C3—C2—H2	120.3	C12—C13—C8	121.6 (2)
C1—C2—H2	120.3	C12—C13—H13	119.2
C2—C3—C4	121.1 (2)	C8—C13—H13	119.2
C2—C3—I1	120.22 (19)	C8—C14—C15	116.0 (2)
C4—C3—I1	118.66 (19)	C8—C14—H14A	108.3
C5—C4—C3	118.9 (3)	C15—C14—H14A	108.3
C5—C4—H4	120.5	C8—C14—H14B	108.3
C3—C4—H4	120.5	C15—C14—H14B	108.3
C4—C5—C6	120.6 (3)	H14A—C14—H14B	107.4
C4—C5—H5	119.7	C16—C15—C14	111.1 (2)
C6—C5—H5	119.7	C16—C15—H15A	109.4
C5—C6—C1	120.3 (3)	C14—C15—H15A	109.4
C5—C6—H6	119.9	C16—C15—H15B	109.4
C1—C6—H6	119.8	C14—C15—H15B	109.4
O1—C7—O2	124.7 (2)	H15A—C15—H15B	108
O1—C7—C1	118.0 (2)	N1—C16—C15	111.6 (2)
O2—C7—C1	117.3 (2)	N1—C16—H16A	109.3
C9—C8—C13	117.7 (2)	C15—C16—H16A	109.3
C9—C8—C14	123.4 (2)	N1—C16—H16B	109.3
C13—C8—C14	118.9 (2)	C15—C16—H16B	109.3
C8—C9—C10	120.9 (3)	H16A—C16—H16B	108
C8—C9—H9	119.5	C16—N1—H1A	115 (2)
C10—C9—H9	119.5	C16—N1—H1B	111 (2)
C11—C10—C9	120.3 (3)	H1A—N1—H1B	102 (3)
C11—C10—H10	119.9	C16—N1—H1C	112 (2)
C9—C10—H10	119.9	H1A—N1—H1C	106 (3)
C10—C11—C12	119.6 (3)	H1B—N1—H1C	110 (3)
C10—C11—H11	120.2
C6—C1—C2—C3	−1.2 (4)	C2—C1—C7—O2	−167.8 (2)
C7—C1—C2—C3	178.5 (2)	C13—C8—C9—C10	0.3 (4)
C1—C2—C3—C4	−0.1 (4)	C14—C8—C9—C10	−179.2 (3)
C1—C2—C3—I1	177.07 (18)	C8—C9—C10—C11	−0.4 (5)
C2—C3—C4—C5	1.7 (4)	C9—C10—C11—C12	0.2 (5)
I1—C3—C4—C5	−175.5 (2)	C10—C11—C12—C13	0.0 (4)
C3—C4—C5—C6	−1.9 (4)	C11—C12—C13—C8	−0.1 (4)
C4—C5—C6—C1	0.6 (4)	C9—C8—C13—C12	−0.1 (4)
C2—C1—C6—C5	1.0 (4)	C14—C8—C13—C12	179.5 (2)
C7—C1—C6—C5	−178.8 (2)	C9—C8—C14—C15	1.7 (4)
C6—C1—C7—O1	−168.2 (2)	C13—C8—C14—C15	−177.8 (2)
C2—C1—C7—O1	12.1 (3)	C8—C14—C15—C16	177.5 (2)
C6—C1—C7—O2	11.9 (3)	C14—C15—C16—N1	−178.2 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2	0.86 (3)	1.94 (3)	2.767 (3)	161 (3)
N1—H1B···O1^i	0.87 (4)	1.95 (4)	2.811 (3)	175 (3)
N1—H1C···O2^ii	0.84 (4)	2.03 (4)	2.856 (3)	172 (3)

Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (ii) x+1/2, −y+3/2, −z+1.