research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 74| Part 9| September 2018| Pages 1276-1280
https://doi.org/10.1107/S2056989018011404

A structural study of 2,4-di­methyl­aniline derivatives

CROSSMARK_Color_square_no_text.svg
Samuel C. Penner,a Maryam Kalvandia and Jamie S. Ritcha*

aDepartment of Chemistry, The University of Winnipeg, Winnipeg MB R3B 2E9, Canada
*Correspondence e-mail: j.ritch@uwinnipeg.ca

Edited by A. J. Lough, University of Toronto, Canada (Received 23 July 2018; accepted 9 August 2018; online 21 August 2018)

Crystallographic studies of nitro­gen-containing small mol­ecules aid in the elucidation of their structure–activity relationships and modes of aggregation. In this study, two previously synthesized mol­ecules are crystallographically characterized for the first time. Reaction of 2,4-di­methyl­aniline with N-bromo­succinimide affords the ortho-brominated derivative 2-bromo-4,6-di­methyl­aniline (1; C8H10BrN), which sublimates in vacuo to afford crystals featuring hydrogen-bonded chains as well as Type I halogen–halogen inter­actions. Conversely, alkyl­ation of two equivalents of 2,4-di­methyl­aniline with 1,2-di­bromo­ethane affords a separable mixture of N,N′-bis­(2,4-di­methyl­phen­yl)piperazine (2; C20H26N2), which was crystallographically characterized, as well as N,N′-bis­(2,4-di­methyl­phen­yl)ethyl­enedi­amine (3).

CCDC references: 1861254; 1861253

Similar articles

1. Chemical context

Anilines are important building blocks for value-added chemicals such as indoles, which feature prominently in therapeutic agents (Humphrey & Kuethe, 2006[Humphrey, G. R. & Kuethe, J. T. (2006). Chem. Rev. 106, 2875-2911.]). Polyaniline, formed by oxidative coupling of aniline, is a valuable conductive polymer used in advanced materials research (Kang et al., 1998[Kang, E. T., Neoh, K. G. & Tan, K. L. (1998). Prog. Polym. Sci. 23, 277-324.]). As they are prone to engage in hydrogen bonding, anilines have also been utilized in crystal engineering studies (Mukherjee et al., 2014[Mukherjee, A., Dixit, K., Sarma, S. P. & Desiraju, G. R. (2014). IUCrJ, 1, 228-239.]). The piperazine functional group is present in a number of active pharmaceutical ingredients. In particular, the widely used anti­fungal agent itracona­zole (Grant & Clissold, 1989[Grant, S. M. & Clissold, S. P. (1989). Drugs, 37, 310-344.]), and anti­bacterial ciprofloxacin (Hooper & Wolfson, 1991[Hooper, D. C. & Wolfson, J. S. (1991). N. Eng. J. Med. 324, 384-394.]) feature piperazine structural units with aryl-group substitution. We have an inter­est in constructing N-heterocyclic carbenes (NHCs) and NHC-derived ligands, which often feature N-aryl groups derived from substituted anilines. Halogenated NHCs can be utilized to fine-tune the steric and electronic properties of transition metal catalysts. It has been demonstated that the presence of fluorine on an aryl group of an NHC ligand influences the E/Z selectivity of a ruthenium cross-metathesis catalyst (Xu et al., 2017[Xu, C., Liu, Z., Torker, S., Shen, X., Xu, D. & Hoveyda, A. H. (2017). J. Am. Chem. Soc. 139, 15640-15643.]). In our efforts to prepare NHC ligands, anilines and N,N′-di­aryldi­amines are commonly used starting materials or synthetic inter­mediates.

In this study, we report the crystallographic characterization of two compounds derived from 2,4-di­methyl­aniline: 2-bromo-4,6-di­methyl­aniline (1) and N,N′-bis­(2,4-di­methyl­phen­yl)piperazine (2). Though available from many commercial suppliers, the crystal structure of 2-bromo-4,6-di­methyl­aniline (1) has not been previously disclosed. Only a few reports of compound 2 can be found in the literature. An early publication (Tikhomirova, 1971[Tikhomirova, R. G. (1971). Zh. Org. Khim. 7, 1480-1483.]) describes the reaction of 2-(2,4-di­methyl­anilino)ethanol with pyridinium chloride, which generates a mixture of 2,4-di­methyl­aniline and the piperazine 2, which was characterized only by elemental analysis, melting point, and boiling point. More recently, piperazine 2 was obtained as a trace by-product in the production of 2-(2,4-di­methyl­anilino)ethanol via palladium-mediated hydrogen autotransfer between 2,4-di­methyl­aniline and ethyl­ene glycol (Llabres-Campaner et al., 2017[Llabres-Campaner, P. J., Ballesteros-Garrido, R., Ballesteros, R. & Abarca, B. (2017). Tetrahedron, 73, 5552-5561.]), and characterized by NMR and IR spectroscopy in addition to high resolution mass spectrometry. No X-ray structural data for compound 2 have been previously disclosed.

[Scheme 1]

2. Structural commentary

The solid-state structure of 1 obtained by slow sublimation is depicted in Fig. 1[link]. Two independent mol­ecules are present in the asymmetric unit, which are hydrogen bonded (Table 1[link]) to each other [d(N⋯N) = 3.172 (5) Å] within the P21/c space group. The two independent mol­ecules exhibit C—Br and C—N bond lengths that are equal within experimental error [1.910 (3)–1.912 (3) Å and 1.394 (4)–1.394 (5) Å, respectively]. The angle between the two mean planes passing through the aromatic rings of the two independent molecules is 80.6 (2)°. The hydrogen atoms on each nitro­gen centre that are not involved in the chains formed by the N—H⋯N interactions are oriented towards the ortho bromine atoms on the aromatic rings. These intra­molecular hydrogen bonds feature donor-acceptor distances of 3.082 (4) and 3.094 (4) Å.

Table 1
Hydrogen-bond geometry (Å, °) for 1[link]

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N1—H1A⋯N2 0.80 (4) 2.44 (4) 3.172 (5) 154 (3)
N1—H1B⋯Br1 0.79 (4) 2.68 (4) 3.094 (4) 115 (4)
N2—H2A⋯N1i 0.81 (4) 2.43 (4) 3.155 (5) 149 (4)
N2—H2B⋯Br2 0.75 (4) 2.70 (4) 3.082 (4) 114 (3)
Symmetry code: (i) x, y+1, z.
[Figure 1]
Figure 1
Displacement ellipsoid plot (50% probability) of the asymmetric unit of compound 1.

X-ray diffraction analysis of 2 revealed a solvent-free structure in the P21 space group (Fig. 2[link]). The asymmetric unit contains one pseudo-Ci symmetric mol­ecule. The central N2C4 ring exhibits a chair conformation. Compound 2 represents the first crystallographically characterized di­aryl­piperazine with methyl groups on the aromatic substituents. The aromatic rings are twisted relative to the N2C4 mean plane, forming angles of 46.8 (1) and 56.9 (1)° for C5–C10 and C13–C18, respectively.

[Figure 2]
Figure 2
Displacement ellipsoid plot (50% probability) of the asymmetric unit of compound 2. Hydrogen atoms are omitted for clarity.

3. Supra­molecular features

Each amino group in compound 1 provides one donor and one acceptor site for the hydrogen-bond inter­actions (Table 1[link]), and chains are observed to form by translation along the crystallographic b axis (Fig. 3[link]). Additionally, the bromine atoms from one of the two independent mol­ecules exhibit weak van der Waals inter­actions to the equivalent sites on adjacent chains, related by an inversion centre (Fig. 4[link]). The distance for this inter­action is 3.537 (1) Å (sum of van der Waals radii for bromine: 3.70 Å; Bondi, 1964[Bondi, A. (1964). J. Phys. Chem. 68, 441-451.]). As the two C—Br⋯Br bond angles are equal (ca 153 °), this classifies as a Type I halogen–halogen inter­action (Cavallo et al., 2016[Cavallo, G., Metrangolo, P., Milani, R., Pilati, T., Priimagi, A., Resnati, G. & Terraneo, G. (2016). Chem. Rev. 116, 2478-2601.]). This type is generally accepted as a dispersion inter­action, as opposed to Type II inter­actions which are weakly electrostatic in nature and require R—X⋯X angles of 90 and 180°. No π–π inter­actions are present in the structure. No significant inter­molecular inter­actions are observed in the crystal packing motif of 2 (Fig. 5[link]).

[Figure 3]
Figure 3
Packing diagram for compound 1. Carbon-bound hydrogen atoms are omitted for clarity.
[Figure 4]
Figure 4
Type I bromine-bromine inter­action in the packing of compound 1. Carbon-bound hydrogen atoms are omitted for clarity.
[Figure 5]
Figure 5
Packing diagram for compound 2. Hydrogen atoms are omitted for clarity.

4. Database survey

The packing motif of compound 1 makes an inter­esting contrast to the structure of the less substituted analogue 2-bromo­aniline, which crystallizes from the melt in the trigonal P31 space group (Nayak et al., 2009[Nayak, S. K., Prathapa, S. J. & Guru Row, T. N. (2009). J. Mol. Struct. 935, 156-160.]). Helical arrangements are formed with each mol­ecule involved in inter­molecular N—H⋯N hydrogen bonds [D⋯A distance of 3.162 (6) Å] and a weaker bromine⋯bromine inter­action (Br⋯Br distance of 3.637 (1) Å), both observed along the 31 screw axes, and with additional intra­molecular N–H⋯Br inter­actions. In the case of the more sterically hindered deriv­ative 1, this arrangement is not feasible and chains are instead adopted.

Most of the crystallographically characterized di­aryl­piperazines feature the chair conformation; a few have been determined in the twist-boat form (Wirth et al., 2012[Wirth, S., Barth, F. & Lorenz, I.-P. (2012). Dalton Trans. 41, 2176-2186.]). Whereas the phenyl groups of piperazine 2 are twisted relative to the N2C4 mean plane, the structure of the less substituted N,N′-di­phenyl­piperazine, which crystallizes in the Pbca space group, exhibits phenyl groups closer to being in conjugation with the nitro­gen lone pairs (Wirth et al., 2012[Wirth, S., Barth, F. & Lorenz, I.-P. (2012). Dalton Trans. 41, 2176-2186.]; Safko & Pike, 2012[Safko, J. P. & Pike, R. D. (2012). J. Chem. Crystallogr. 42, 981-987.]). The sum of the bond angles around nitro­gen is quite similar between the two structures (2: 338–341°; N,N′-di­phenyl­piperazine: 343°), though the N–Car­yl bond lengths are slightly shortened in the phenyl-substituted analogue [2: 1.426 (3)–1.431 (3) Å; N,N′-di­phenyl­piperazine: 1.4157 (15) Å], indicating that resonance delocalization is a perhaps a minor effect, if present, while packing effects likely dominate. The structures of 2 and the phenyl analogue are overlaid in Fig. 6[link] for visual comparison.

[Figure 6]
Figure 6
Structure of compound 2 overlaid with N,N′-di­phenyl­piperazine (CCDC refcode WAQNUZ01).

5. Synthesis and crystallization

We prepared compound 1 by electrophilic aromatic bromination of the parent aniline, as reported previously for related compounds (Das et al., 2007[Das, B., Venkateswarlu, K., Majhi, A., Siddaiah, V. & Reddy, K. R. (2007). J. Mol. Catal. A: Chem. 267, 30-33.]). The resultant red-brown solid was reasonably pure by 1H NMR, however it was easily sublimated to afford very pure colourless material, leaving behind oily reddish-brown impurities.

The piperazine compound 2 was unexpectedly obtained as a by-product during the synthesis of N,N′-bis­(2,4-di­methyl­phen­yl)ethyl­enedi­amine (3) via a condensation reaction. Compound 3 is evidently able to compete with 2,4-di­methyl­aniline as a nucleophile towards 1,2-di­bromo­ethane, once formed. Both desired main product 3 and by-product 2 were isolated after separation by column chromatography.

Synthetic protocols were conducted under ambient conditions using ACS-grade solvents. All chemicals were obtained from commercial sources and used as received. NMR spectra were collected using a Bruker 400 MHz Avance III spectrometer. 1H and 13C resonances are referenced to residual CHCl3 or CDCl3, respectively, using the reported values relative to SiMe4 (Fulmer et al., 2010[Fulmer, G. R., Miller, A. J. M., Sherden, N. H., Gottlieb, H. E., Nudelman, A., Stoltz, B. M., Bercaw, J. E. & Goldberg, K. I. (2010). Organometallics, 29, 2176-2179.]).

5.1. Preparation of 2-bromo-4,6-di­methyl­aniline (1)

A 100 mL round-bottom flask equipped with a magnetic stir bar was charged with N-bromo­succinimide (3.4896 g, 19.607 mmol), ammonium acetate (0.1583 g, 2.054 mmol), and aceto­nitrile (60 mL). The reagent 2,4-di­methyl­aniline (2.4297 g, 20.050 mmol) was added slowly, by pipette. The resulting mixture was left to stir at room temperature for 90 min. The solvent was removed under vacuum to produce a reddish-brown solid. Water (45 mL) and di­chloro­methane (45 mL) were added, and the mixture was transferred to a separatory funnel. The organic layer was separated and washed with water (3 × 30 mL), saturated sodium thio­sulfate (30 mL), and brine (30 mL). After drying the organic layer with magnesium sulfate, the mixture was filtered and the volatiles removed under vacuum to afford a brown crystalline solid (3.2723 g, 83.42%). 1H NMR (CDCl3, 400 MHz): δ 7.15 (s, 1H), 7.14 (s, 1H), 3.93 (s, 2H), 2.22 (s, 3H), 2.21 (s, 3H). The procedure was based on one reported for similar aniline derivatives (Das et al., 2007). The product can be purified by sublimation under static vacuum with heating to 308 K for 3 d. Large X-ray quality crystals of the product were obtained by slow sublimation under ambient conditions in a capped glass vial containing the crude product, over a period of months.

5.2. Preparation of N,N′-bis­(2,4-di­methyl­phen­yl)piperazine (2) and N,N′-bis­(2,4-di­methyl­phen­yl)ethyl­enedi­amine (3)

A 100 mL round-bottom flask equipped with a magnetic stir bar was charged with 2,4-di­methyl­aniline (9.21 mL, 74.5 mmol), 1,2-di­bromo­ethane (3.21 mL, 37.3 mmol), and N,N′-diiso­propyl­ethyl­amine (12.98 mL, 74.5 mmol), and fitted with a reflux condenser and drying tube. The mixture was heated to 403 K for 4 h, then cooled to room temperature affording a red solid mass. To this was added H2O (50 mL) before extraction with CH2Cl2 (30 mL). The organic phase was washed with H2O (50 mL), and to the combined aqueous extracts was added 1 M NaOH(aq) (40 mL), and this mixture was extracted with CH2Cl2 (50 mL). The combined organic extracts were washed with H2O (30 mL) and brine (30 mL), dried over MgSO4, deca­nted into a round-bottom flask, and dried under vacuum to afford a dark orange–red liquid. Addition of hexa­nes (40 mL) resulted in the precipitation of crystalline material. The solid material was redissolved by warming the hexa­nes, and the resultant clear red solution was stored overnight at 238 K. The mother liquor was deca­nted and the remaining solid material was washed with cold hexa­nes (3 × 3 mL) and dried under vacuum to afford a beige solid (5.4730 g). NMR data indicated that the product was a 90:10 mol% mixture of 1,2-di­amine 3 and piperazine 2, obtained with a 69% yield of products based on 1,2-di­bromo­ethane. Separation of the compounds was achieved by silica gel flash chromatography. Elution of 1.3223 g of a mixture with CH2Cl2 afforded piperazine 2 as a pale-tan crystalline solid (Rf = 0.75, 124.0 mg, 60% recovery) and di­amine 3 as a pale-yellow solid (Rf = 0.21, 851.4 mg, 84% recovery). The 1H and 13C chemical shifts and assignments for di­amine in CDCl3 differed from the reported values (Türkmen & Çetinkaya, 2006[Türkmen, H. & Çetinkaya, B. (2006). J. Organomet. Chem. 691, 3749-3759.]). Di­amine 3: 1H NMR (CDCl3): δ 6.96 (d, 3JHH = 8.1 Hz, 2H, aromatic 5-H), 6.91 (s, 2H, aromatic 3-H), 6.61 (d, 3JHH = 8.1 Hz, 2H, aromatic 6-H), 3.61 (br s, 2H, NH), 3.47 (s, 4H, CH2), 2.25 (s, 6H, aromatic 4-CH3), 2.11 (s, 6H, aromatic 2-CH3). 13C{1H} NMR (CDCl3): δ 144.0 (s), 131.3 (s), 127.6 (s), 126.8 (s), 122.8 (s), 110.4 (s), 43.8 (s, CH2), 20.5 (s), 17.7 (s). Piperazine 2: 1H NMR (CDCl3): δ 7.03 (s, 2H, aromatic CH), 7.01 (s, 4H, aromatic CH), 3.04 (s, 8H, CH2), 2.33 (s, 6H, CH3), 2.30 (s, 6H, CH3). 13C{1H} NMR (CDCl3): δ 149.5 (s), 132.9 (s), 132.8 (s), 132.0 (s), 127.2 (s), 119.3 (s), 52.8 (s), 20.9 (s), 18.0 (s). The procedure was based on that used for the fluoro analogue (Day et al., 2011[Day, G. S., Pan, B., Kellenberger, D. L., Foxman, B. M. & Thomas, C. M. (2011). Chem. Commun. 47, 3634-3636.]). Crystals of piperazine 2 were grown by slow evaporation of a toluene solution of the compound, at room temperature.

6. Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 2[link]. The N—H protons of compound 1 were located in the difference map and refined freely. The piperazine 2 crystallized in the non-centric group P21; no heavy atoms are present in the structure, therefore the Flack parameter was not calculated. Carbon-bound hydrogen atoms were placed in calculated positions (C—H = 0.95–0.99 Å) and refined according to a riding model, with fixed Uiso values of 1.2 times (CH and CH2 groups) and 1.5 times (CH3 groups) the parent atom.

Table 2
Experimental details

  C8H10BrN C20H26N2
Crystal data
Mr 200.08 294.43
Crystal system, space group Monoclinic, P21/c Monoclinic, P21
Temperature (K) 150 150
a, b, c (Å) 16.4359 (10), 5.1917 (3), 20.5792 (11) 7.6563 (2), 13.2685 (4), 8.3688 (2)
β (°) 110.748 (4) 96.968 (2)
V (Å3) 1642.15 (17) 843.89 (4)
Z 8 2
Radiation type Mo Kα Mo Kα
μ (mm−1) 4.93 0.07
Crystal size (mm) 0.28 × 0.15 × 0.08 0.28 × 0.15 × 0.08
 
Data collection
Diffractometer Bruker APEXII CCD Bruker APEXII CCD
Absorption correction Numerical (SADABS; Bruker, 2015[Bruker (2015). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Numerical (SADABS; Bruker, 2015[Bruker (2015). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.542, 0.746 0.894, 0.954
No. of measured, independent and observed [I > 2σ(I)] reflections 17969, 2903, 2170 13424, 3289, 2588
Rint 0.052 0.074
(sin θ/λ)max (Å−1) 0.595 0.625
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.030, 0.069, 1.00 0.040, 0.095, 1.05
No. of reflections 2903 3289
No. of parameters 201 203
No. of restraints 0 1
H-atom treatment H atoms treated by a mixture of independent and constrained refinement H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.45, −0.38 0.20, −0.19
Computer programs: APEX2 and SAINT (Bruker, 2015[Bruker (2015). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]) and OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]).

Supporting information

CCDC references: 1861254; 1861253

Crystal structure: contains datablocks 1, 2. DOI: https://doi.org/10.1107/S2056989018011404/lh5879sup1.cif

Structure factors: contains datablock 1. DOI: https://doi.org/10.1107/S2056989018011404/lh58791sup2.hkl

Structure factors: contains datablock 2. DOI: https://doi.org/10.1107/S2056989018011404/lh58792sup3.hkl

checkCIF report


Computing details top

For both structures, data collection: APEX2 (Bruker, 2015); cell refinement: SAINT (Bruker, 2015); data reduction: SAINT (Bruker, 2015); program(s) used to solve structure: ShelXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

2-Bromo-4,6-dimethylaniline (1) top
Crystal data top
C8H10BrNF(000) = 800
Mr = 200.08Dx = 1.619 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 16.4359 (10) ÅCell parameters from 6401 reflections
b = 5.1917 (3) Åθ = 2.7–27.3°
c = 20.5792 (11) ŵ = 4.93 mm−1
β = 110.748 (4)°T = 150 K
V = 1642.15 (17) Å3Prism, colourless
Z = 80.28 × 0.15 × 0.08 mm
Data collection top
Bruker APEXII CCD
diffractometer		2170 reflections with I > 2σ(I)
φ and ω scansRint = 0.052
Absorption correction: numerical
(SADABS; Bruker, 2015)		θmax = 25.0°, θmin = 2.7°
Tmin = 0.542, Tmax = 0.746h = −19→19
17969 measured reflectionsk = −6→6
2903 independent reflectionsl = −24→24
Refinement top
Refinement on F2Primary atom site location: dual
Least-squares matrix: fullHydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.030H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.069 w = 1/[σ2(Fo2) + (0.0241P)2 + 3.2572P]
where P = (Fo2 + 2Fc2)/3
S = 1.00(Δ/σ)max = 0.001
2903 reflectionsΔρmax = 0.45 e Å−3
201 parametersΔρmin = −0.38 e Å−3
0 restraints
Special details top

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

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.97945 (2)0.20330 (8)0.56141 (2)0.03211 (12)
N10.8334 (2)0.6135 (7)0.52086 (17)0.0268 (7)
H1A0.815 (2)0.756 (8)0.5140 (19)0.020 (11)*
H1B0.871 (3)0.593 (8)0.505 (2)0.035 (13)*
C10.8515 (2)0.5157 (6)0.58759 (17)0.0194 (7)
C20.9120 (2)0.3209 (7)0.61459 (17)0.0214 (8)
C30.9268 (2)0.2078 (7)0.67863 (17)0.0228 (8)
H30.9688100.0746700.6948150.027*
C40.8800 (2)0.2901 (7)0.71895 (17)0.0222 (7)
C50.8196 (2)0.4857 (7)0.69261 (17)0.0216 (8)
H50.7871500.5436730.7199260.026*
C60.8041 (2)0.6005 (7)0.62857 (18)0.0208 (8)
C70.8930 (2)0.1658 (8)0.78885 (19)0.0315 (9)
H7A0.881827−0.0196290.7824700.047*
H7B0.8526110.2426540.8087430.047*
H7C0.9529530.1941960.8203560.047*
C80.7372 (2)0.8172 (7)0.60306 (18)0.0232 (8)
H8A0.7665000.9756650.5975820.035*
H8B0.7087090.8458030.6370080.035*
H8C0.6934200.7689350.5582450.035*
Br20.73280 (2)0.70006 (8)0.33028 (2)0.03345 (12)
N20.7421 (2)1.1155 (7)0.43964 (19)0.0262 (7)
H2A0.745 (3)1.262 (8)0.454 (2)0.026 (12)*
H2B0.771 (3)1.104 (8)0.419 (2)0.024 (12)*
C90.6585 (2)1.0176 (7)0.40744 (17)0.0217 (8)
C100.6405 (2)0.8241 (7)0.35792 (17)0.0220 (8)
C110.5595 (2)0.7119 (7)0.32828 (17)0.0254 (8)
H110.5504930.5800420.2944490.030*
C120.4915 (2)0.7929 (7)0.34820 (18)0.0264 (8)
C130.5085 (2)0.9868 (7)0.39782 (17)0.0237 (8)
H130.4624541.0435600.4120550.028*
C140.5893 (2)1.1007 (7)0.42741 (17)0.0218 (8)
C150.4027 (2)0.6683 (8)0.3184 (2)0.0364 (10)
H15B0.3711370.7405380.2723030.055*
H15C0.3700390.7016680.3491320.055*
H15A0.4095490.4821290.3143860.055*
C160.6042 (2)1.3165 (6)0.48222 (16)0.0191 (7)
H16C0.6525701.2688410.5244840.029*
H16A0.5512921.3396290.4932380.029*
H16B0.6180511.4777730.4636840.029*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0301 (2)0.0367 (2)0.0358 (2)0.00185 (18)0.01951 (18)−0.00371 (18)
N10.0294 (19)0.0256 (19)0.0247 (17)−0.0004 (16)0.0088 (16)0.0017 (15)
C10.0179 (18)0.0172 (18)0.0196 (18)−0.0040 (14)0.0024 (15)0.0002 (14)
C20.0168 (17)0.0228 (19)0.0256 (19)−0.0034 (16)0.0089 (15)−0.0073 (16)
C30.0155 (16)0.0221 (18)0.0278 (19)0.0014 (15)0.0041 (15)0.0003 (16)
C40.0169 (17)0.0249 (18)0.0232 (18)−0.0065 (16)0.0053 (14)−0.0025 (16)
C50.0162 (17)0.0264 (19)0.0228 (18)−0.0023 (15)0.0078 (15)−0.0085 (16)
C60.0161 (17)0.0178 (17)0.0258 (19)−0.0015 (15)0.0042 (15)−0.0035 (16)
C70.029 (2)0.037 (2)0.030 (2)−0.0012 (18)0.0115 (17)0.0041 (18)
C80.0238 (18)0.0161 (17)0.0259 (18)−0.0007 (16)0.0040 (15)−0.0055 (16)
Br20.0361 (2)0.0404 (2)0.0305 (2)0.00730 (19)0.02002 (18)0.00411 (18)
N20.0225 (18)0.0237 (19)0.0312 (19)−0.0051 (15)0.0081 (16)−0.0007 (16)
C90.0233 (19)0.0205 (19)0.0193 (18)0.0011 (15)0.0050 (15)0.0071 (15)
C100.027 (2)0.0234 (19)0.0193 (17)0.0047 (16)0.0126 (15)0.0056 (16)
C110.031 (2)0.0235 (19)0.0196 (17)−0.0008 (17)0.0069 (16)−0.0017 (16)
C120.0242 (19)0.0282 (19)0.0230 (18)0.0005 (17)0.0037 (15)0.0060 (17)
C130.0226 (19)0.027 (2)0.0226 (19)0.0063 (16)0.0097 (15)0.0062 (16)
C140.0257 (19)0.0193 (17)0.0185 (17)0.0037 (15)0.0052 (15)0.0030 (15)
C150.029 (2)0.042 (3)0.033 (2)−0.0064 (19)0.0049 (18)0.000 (2)
C160.0192 (17)0.0139 (17)0.0210 (17)0.0037 (15)0.0031 (14)0.0038 (15)
Geometric parameters (Å, º) top
Br1—C21.912 (3)Br2—C101.910 (3)
N1—H1A0.80 (4)N2—H2A0.81 (4)
N1—H1B0.79 (4)N2—H2B0.75 (4)
N1—C11.394 (4)N2—C91.394 (5)
C1—C21.390 (5)C9—C101.386 (5)
C1—C61.406 (5)C9—C141.407 (5)
C2—C31.383 (5)C10—C111.382 (5)
C3—H30.9500C11—H110.9500
C3—C41.384 (5)C11—C121.385 (5)
C4—C51.389 (5)C12—C131.390 (5)
C4—C71.521 (5)C12—C151.513 (5)
C5—H50.9500C13—H130.9500
C5—C61.386 (5)C13—C141.382 (5)
C6—C81.531 (5)C14—C161.546 (5)
C7—H7A0.9800C15—H15B0.9800
C7—H7B0.9800C15—H15C0.9800
C7—H7C0.9800C15—H15A0.9800
C8—H8A0.9800C16—H16C0.9800
C8—H8B0.9800C16—H16A0.9800
C8—H8C0.9800C16—H16B0.9800
H1A—N1—H1B111 (4)H2A—N2—H2B108 (4)
C1—N1—H1A117 (3)C9—N2—H2A116 (3)
C1—N1—H1B115 (3)C9—N2—H2B115 (3)
N1—C1—C6120.5 (3)N2—C9—C14120.8 (3)
C2—C1—N1122.1 (3)C10—C9—N2122.1 (3)
C2—C1—C6117.3 (3)C10—C9—C14117.0 (3)
C1—C2—Br1118.8 (3)C9—C10—Br2118.6 (3)
C3—C2—Br1117.9 (3)C11—C10—Br2118.0 (3)
C3—C2—C1123.3 (3)C11—C10—C9123.4 (3)
C2—C3—H3120.2C10—C11—H11120.2
C2—C3—C4119.5 (3)C10—C11—C12119.6 (3)
C4—C3—H3120.2C12—C11—H11120.2
C3—C4—C5117.7 (3)C11—C12—C13117.7 (3)
C3—C4—C7121.0 (3)C11—C12—C15120.9 (3)
C5—C4—C7121.4 (3)C13—C12—C15121.4 (3)
C4—C5—H5118.3C12—C13—H13118.5
C6—C5—C4123.4 (3)C14—C13—C12123.0 (3)
C6—C5—H5118.3C14—C13—H13118.5
C1—C6—C8120.5 (3)C9—C14—C16120.0 (3)
C5—C6—C1118.8 (3)C13—C14—C9119.3 (3)
C5—C6—C8120.7 (3)C13—C14—C16120.7 (3)
C4—C7—H7A109.5C12—C15—H15B109.5
C4—C7—H7B109.5C12—C15—H15C109.5
C4—C7—H7C109.5C12—C15—H15A109.5
H7A—C7—H7B109.5H15B—C15—H15C109.5
H7A—C7—H7C109.5H15B—C15—H15A109.5
H7B—C7—H7C109.5H15C—C15—H15A109.5
C6—C8—H8A109.5C14—C16—H16C109.5
C6—C8—H8B109.5C14—C16—H16A109.5
C6—C8—H8C109.5C14—C16—H16B109.5
H8A—C8—H8B109.5H16C—C16—H16A109.5
H8A—C8—H8C109.5H16C—C16—H16B109.5
H8B—C8—H8C109.5H16A—C16—H16B109.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···N20.80 (4)2.44 (4)3.172 (5)154 (3)
N1—H1B···Br10.79 (4)2.68 (4)3.094 (4)115 (4)
N2—H2A···N1i0.81 (4)2.43 (4)3.155 (5)149 (4)
N2—H2B···Br20.75 (4)2.70 (4)3.082 (4)114 (3)
Symmetry code: (i) x, y+1, z.
1,4-Bis(2,4-dimethylphenyl)piperazine (2) top
Crystal data top
C20H26N2F(000) = 320
Mr = 294.43Dx = 1.159 Mg m−3
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
a = 7.6563 (2) ÅCell parameters from 4924 reflections
b = 13.2685 (4) Åθ = 2.5–31.6°
c = 8.3688 (2) ŵ = 0.07 mm−1
β = 96.968 (2)°T = 150 K
V = 843.89 (4) Å3Block, clear colourless
Z = 20.28 × 0.15 × 0.08 mm
Data collection top
Bruker APEXII CCD
diffractometer		2588 reflections with I > 2σ(I)
φ and ω scansRint = 0.074
Absorption correction: numerical
(SADABS; Bruker, 2015)		θmax = 26.4°, θmin = 2.9°
Tmin = 0.894, Tmax = 0.954h = −9→9
13424 measured reflectionsk = −16→16
3289 independent reflectionsl = −10→10
Refinement top
Refinement on F2Primary atom site location: dual
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.040H-atom parameters constrained
wR(F2) = 0.095 w = 1/[σ2(Fo2) + (0.0509P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.001
3289 reflectionsΔρmax = 0.20 e Å−3
203 parametersΔρmin = −0.19 e Å−3
1 restraint
Special details top

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

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.8569 (2)0.56722 (15)0.4969 (3)0.0224 (5)
N20.6207 (2)0.45272 (16)0.6642 (3)0.0220 (5)
C10.9201 (3)0.4876 (2)0.6112 (3)0.0246 (6)
H1A1.0400680.5044630.6620980.029*
H1B0.9262700.4230480.5528780.029*
C20.7987 (3)0.4762 (2)0.7399 (3)0.0259 (6)
H2A0.8417060.4213800.8148450.031*
H2B0.7971170.5394670.8024110.031*
C30.6774 (3)0.5442 (2)0.4243 (3)0.0258 (6)
H3A0.6768460.4802190.3634290.031*
H3B0.6344240.5984450.3482340.031*
C40.5577 (3)0.5352 (2)0.5544 (4)0.0268 (6)
H4A0.5573860.5992820.6149190.032*
H4B0.4358570.5211200.5053480.032*
C50.4986 (3)0.41979 (19)0.7690 (3)0.0222 (6)
C60.3523 (3)0.3616 (2)0.7052 (3)0.0209 (6)
C70.2394 (3)0.3254 (2)0.8102 (3)0.0234 (6)
H70.1405470.2864760.7672760.028*
C80.2643 (3)0.3435 (2)0.9749 (3)0.0252 (6)
C90.4095 (3)0.4009 (2)1.0347 (4)0.0302 (7)
H90.4305690.4145411.1468140.036*
C100.5236 (3)0.4385 (2)0.9336 (3)0.0275 (6)
H100.6212910.4780730.9775450.033*
C110.3192 (3)0.3355 (2)0.5289 (3)0.0264 (6)
H11A0.2547470.2716610.5154050.040*
H11B0.4318920.3288480.4853780.040*
H11C0.2495300.3890400.4711080.040*
C120.1416 (4)0.3004 (2)1.0852 (4)0.0350 (7)
H12A0.0247840.2906611.0251180.052*
H12B0.1329780.3469971.1747350.052*
H12C0.1873030.2354161.1275010.052*
C130.9794 (3)0.59108 (19)0.3864 (3)0.0212 (6)
C141.1194 (3)0.65758 (19)0.4351 (3)0.0216 (6)
C151.2329 (3)0.6837 (2)0.3236 (3)0.0231 (6)
H151.3255130.7298480.3554210.028*
C161.2165 (3)0.64531 (19)0.1680 (4)0.0251 (6)
C171.0792 (3)0.5787 (2)0.1236 (3)0.0275 (6)
H171.0650470.5507020.0182990.033*
C180.9624 (3)0.5526 (2)0.2311 (3)0.0274 (6)
H180.8688670.5073380.1977030.033*
C191.1465 (3)0.7012 (2)0.6018 (4)0.0296 (7)
H19A1.2101570.6526300.6754870.044*
H19B1.0320380.7159460.6376380.044*
H19C1.2150950.7635450.6010500.044*
C201.3401 (3)0.6774 (2)0.0498 (4)0.0307 (7)
H20A1.2909040.736048−0.0111670.046*
H20B1.3548090.621855−0.0245760.046*
H20C1.4545900.6951660.1083460.046*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0194 (10)0.0218 (12)0.0258 (12)0.0019 (8)0.0017 (9)0.0032 (10)
N20.0184 (10)0.0228 (12)0.0238 (12)0.0004 (8)−0.0005 (9)0.0036 (10)
C10.0180 (11)0.0238 (13)0.0311 (17)0.0023 (10)−0.0007 (10)0.0038 (12)
C20.0213 (11)0.0271 (15)0.0284 (16)−0.0012 (10)−0.0010 (10)0.0042 (13)
C30.0204 (12)0.0288 (14)0.0276 (15)0.0024 (10)0.0003 (10)0.0061 (12)
C40.0188 (12)0.0265 (14)0.0344 (17)0.0025 (10)0.0011 (11)0.0062 (13)
C50.0200 (12)0.0220 (14)0.0244 (16)0.0035 (9)0.0015 (10)0.0031 (11)
C60.0198 (12)0.0211 (13)0.0213 (14)0.0044 (9)0.0004 (10)0.0006 (11)
C70.0195 (12)0.0223 (14)0.0276 (16)−0.0006 (10)0.0000 (10)−0.0009 (12)
C80.0258 (12)0.0217 (14)0.0287 (16)0.0004 (10)0.0060 (11)−0.0009 (12)
C90.0348 (14)0.0343 (16)0.0214 (15)−0.0017 (12)0.0031 (12)−0.0067 (13)
C100.0266 (13)0.0244 (14)0.0306 (16)−0.0053 (11)0.0003 (11)−0.0030 (12)
C110.0222 (12)0.0295 (15)0.0269 (16)−0.0016 (11)0.0004 (11)−0.0008 (13)
C120.0395 (15)0.0368 (18)0.0297 (18)−0.0049 (12)0.0085 (13)−0.0013 (14)
C130.0171 (11)0.0190 (13)0.0271 (16)0.0027 (9)0.0012 (10)0.0026 (11)
C140.0192 (11)0.0221 (14)0.0227 (15)0.0038 (10)−0.0010 (10)0.0013 (11)
C150.0208 (12)0.0207 (13)0.0264 (16)−0.0017 (10)−0.0025 (11)0.0002 (11)
C160.0241 (13)0.0235 (14)0.0270 (16)0.0029 (10)−0.0003 (11)0.0027 (12)
C170.0301 (14)0.0291 (15)0.0227 (15)−0.0014 (11)0.0006 (11)−0.0064 (12)
C180.0228 (12)0.0275 (15)0.0308 (17)−0.0056 (11)−0.0012 (11)−0.0030 (12)
C190.0266 (12)0.0358 (17)0.0261 (16)−0.0042 (11)0.0026 (11)−0.0036 (13)
C200.0318 (14)0.0351 (17)0.0259 (17)−0.0037 (12)0.0065 (12)−0.0024 (13)
Geometric parameters (Å, º) top
N1—C11.466 (3)C9—C101.381 (4)
N1—C31.466 (3)C10—H100.9500
N1—C131.431 (3)C11—H11A0.9800
N2—C21.465 (3)C11—H11B0.9800
N2—C41.472 (3)C11—H11C0.9800
N2—C51.426 (3)C12—H12A0.9800
C1—H1A0.9900C12—H12B0.9800
C1—H1B0.9900C12—H12C0.9800
C1—C21.514 (4)C13—C141.410 (3)
C2—H2A0.9900C13—C181.388 (4)
C2—H2B0.9900C14—C151.393 (4)
C3—H3A0.9900C14—C191.502 (4)
C3—H3B0.9900C15—H150.9500
C3—C41.511 (4)C15—C161.390 (4)
C4—H4A0.9900C16—C171.390 (4)
C4—H4B0.9900C16—C201.511 (4)
C5—C61.411 (3)C17—H170.9500
C5—C101.390 (4)C17—C181.387 (4)
C6—C71.391 (4)C18—H180.9500
C6—C111.507 (4)C19—H19A0.9800
C7—H70.9500C19—H19B0.9800
C7—C81.389 (4)C19—H19C0.9800
C8—C91.390 (4)C20—H20A0.9800
C8—C121.508 (4)C20—H20B0.9800
C9—H90.9500C20—H20C0.9800
C3—N1—C1109.8 (2)C5—C10—H10119.3
C13—N1—C1112.98 (18)C9—C10—C5121.4 (2)
C13—N1—C3115.7 (2)C9—C10—H10119.3
C2—N2—C4109.2 (2)C6—C11—H11A109.5
C5—N2—C2116.4 (2)C6—C11—H11B109.5
C5—N2—C4114.96 (19)C6—C11—H11C109.5
N1—C1—H1A109.5H11A—C11—H11B109.5
N1—C1—H1B109.5H11A—C11—H11C109.5
N1—C1—C2110.71 (19)H11B—C11—H11C109.5
H1A—C1—H1B108.1C8—C12—H12A109.5
C2—C1—H1A109.5C8—C12—H12B109.5
C2—C1—H1B109.5C8—C12—H12C109.5
N2—C2—C1109.4 (2)H12A—C12—H12B109.5
N2—C2—H2A109.8H12A—C12—H12C109.5
N2—C2—H2B109.8H12B—C12—H12C109.5
C1—C2—H2A109.8C14—C13—N1119.1 (2)
C1—C2—H2B109.8C18—C13—N1122.0 (2)
H2A—C2—H2B108.2C18—C13—C14118.9 (2)
N1—C3—H3A109.7C13—C14—C19121.6 (2)
N1—C3—H3B109.7C15—C14—C13118.4 (2)
N1—C3—C4109.7 (2)C15—C14—C19119.9 (2)
H3A—C3—H3B108.2C14—C15—H15118.6
C4—C3—H3A109.7C16—C15—C14122.9 (2)
C4—C3—H3B109.7C16—C15—H15118.6
N2—C4—C3109.1 (2)C15—C16—C20121.2 (2)
N2—C4—H4A109.9C17—C16—C15117.6 (3)
N2—C4—H4B109.9C17—C16—C20121.2 (3)
C3—C4—H4A109.9C16—C17—H17119.6
C3—C4—H4B109.9C18—C17—C16120.8 (3)
H4A—C4—H4B108.3C18—C17—H17119.6
C6—C5—N2119.0 (2)C13—C18—H18119.3
C10—C5—N2122.2 (2)C17—C18—C13121.4 (2)
C10—C5—C6118.7 (2)C17—C18—H18119.3
C5—C6—C11121.8 (2)C14—C19—H19A109.5
C7—C6—C5118.4 (2)C14—C19—H19B109.5
C7—C6—C11119.7 (2)C14—C19—H19C109.5
C6—C7—H7118.5H19A—C19—H19B109.5
C8—C7—C6123.1 (2)H19A—C19—H19C109.5
C8—C7—H7118.5H19B—C19—H19C109.5
C7—C8—C9117.4 (2)C16—C20—H20A109.5
C7—C8—C12121.4 (2)C16—C20—H20B109.5
C9—C8—C12121.2 (3)C16—C20—H20C109.5
C8—C9—H9119.5H20A—C20—H20B109.5
C10—C9—C8121.0 (3)H20A—C20—H20C109.5
C10—C9—H9119.5H20B—C20—H20C109.5
 

Acknowledgements

Dr David Herbert (Department of Chemistry, University of Manitoba) is thanked for access to a single-crystal X-ray diffractometer.

Funding information

Funding for this research was provided by: The University of Winnipeg.

References

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ISSN: 2056-9890
Volume 74| Part 9| September 2018| Pages 1276-1280
https://doi.org/10.1107/S2056989018011404
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