organic compounds Experimental Acta Crystallographica Section E Structure Reports Online Crystal data ISSN 1600-5368 2,5-Bis{[( )-(S)-1-(4-bromophenyl)ethyl]iminomethyl}thiophene Angel Mendoza,a* Sylvain Bernès,b Guadalupe Hernández-Téllez,c Oscar Portillo-Morenoc and René Gutiérrezc a Centro de Quı́mica, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, 72570 Puebla, Puebla, Mexico, bDEP, Facultad de Ciencias Quı́micas, UANL, Guerrero y Progreso S/N, Col. Treviño 64570 Monterrey, NL, Mexico, and c Laboratorio de Sı́ntesis de Complejos, Facultad de Ciencias Quı́micas, Benemérita Universidad Autónoma de Puebla, PO Box 1067, 72001 Puebla, Puebla, Mexico Correspondence e-mail: angel.mendoza@correo.buap.mx Received 7 February 2014; accepted 18 February 2014 C22H20Br2N2S Mr = 504.27 Monoclinic, C2 a = 24.5329 (15) Å b = 5.9762 (5) Å c = 7.5944 (5) Å = 98.536 (6) V = 1101.11 (14) Å3 Z=2 Mo K radiation  = 3.79 mm 1 T = 298 K 0.52  0.15  0.06 mm Data collection Agilent Xcalibur (Atlas, Gemini) diffractometer Absorption correction: numerical (CrysAlis PRO; Agilent, 2013) Tmin = 0.400, Tmax = 0.815 6101 measured reflections 2107 independent reflections 1630 reflections with I > 2(I) Rint = 0.035 Refinement R[F 2 > 2(F 2)] = 0.036 wR(F 2) = 0.072 S = 1.03 2107 reflections 124 parameters 1 restraint H-atom parameters constrained
max = 0.20 e Å 3
min = 0.35 e Å 3 Absolute structure: Flack (1983), 914 Friedel pairs Absolute structure parameter: 0.011 (8) Key indicators: single-crystal X-ray study; T = 298 K; mean (C–C) = 0.007 Å; R factor = 0.036; wR factor = 0.072; data-to-parameter ratio = 17.0. The title compound, C22H20Br2N2S, was synthesized under solvent-free conditions. The molecule shows crystallographic C2 symmetry, with the S atom of the central thiophene ring lying on a twofold rotation axis. Furthermore, as a consequence of the (S,S) stereochemistry, the molecule has a twisted conformation. The dihedral angle between the thiophene and benzene rings is 72.7 (2) and that between the two benzene rings is 55.9 (2) . In the crystal, molecules are arranged in a chevron-like pattern, without any significant intermolecular interactions. Related literature For the solvent-free organic synthesis, see: Tanaka & Toda (2000). For the structure of a chiral bis-aldimine compound, see: Espinosa Leija et al. (2009). For structures of thiophenes substituted in positions 2 and 5 by imine functionalities, see: Bernès et al. (2013); Kudyakova et al. (2012). Acta Cryst. (2014). E70, o345 Data collection: CrysAlis PRO (Agilent, 2013); cell refinement: CrysAlis PRO; data reduction: CrysAlis RED (Agilent, 2013); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012). Support from VIEP-UAP (GUPJ-NAT12-G-2013) is acknowledged. Supporting information for this paper is available from the IUCr electronic archives (Reference: IS5340). References Agilent (2013). CrysAlis PRO and CrysAlis RED. Agilent Technologies Inc., Santa Clara, CA, USA. Bernès, S., Hernández-Téllez, G., Sharma, M., Portillo-Moreno, O. & Gutiérrez, R. (2013). Acta Cryst. E69, o1428. Espinosa Leija, A., Hernández, G., Cruz, S., Bernès, S. & Gutiérrez, R. (2009). Acta Cryst. E65, o1316. Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Flack, H. D. (1983). Acta Cryst. A39, 876–881. Kudyakova, Y. S., Burgart, Y. V., Slepukhin, P. A. & Saloutin, V. I. (2012). Mendeleev Commun. 22, 284–286. Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Tanaka, K. & Toda, F. (2000). Chem. Rev. 100, 1025–1074. doi:10.1107/S1600536814003651 Mendoza et al. o345 supporting information supporting information Acta Cryst. (2014). E70, o345 [doi:10.1107/S1600536814003651] 2,5-Bis{[(−)-(S)-1-(4-bromophenyl)ethyl]iminomethyl}thiophene Angel Mendoza, Sylvain Bernès, Guadalupe Hernández-Téllez, Oscar Portillo-Moreno and René Gutiérrez S1. Comment In continuation of our work focused on chiral bisimines (Espinosa Leija et al., 2009; Bernès et al., 2013), we have now synthesized the title compound under the solvent-free approach because of the cleaner, safer, and easier aspects to perform in the synthetic work. So, solvent-free conditions are becoming more popular and it is often claimed that the best solvent is no solvent. (Tanaka & Toda, 2000). The bis-aldimine compound shows an E configuration over every imine bond (Fig. 1). The molecule is an (S,S) diastereoisomer as expected by synthetic procedure. The asymmetric unit contains a half-molecule. The S atom of the molecule is located on a twofold rotation axis of the space group C2. and as a consequence the Br-aldimines groups are placed opposite to the central thiophene ring. Only some previous reports of 2,5-thiophene compounds with achiral or chiral substituents have showed C2 crystallographic symmetry like title compound (Kudyakova et al., 2012, space group C2/c; Bernès et al., 2013, space group P22121). The crystal packing does not feature any particular interactions (intra or intermolecular) and the supramolecular arrangement in the solid state shows a chevron-like pattern viewed along the b axis (Fig. 2). S2. Experimental Under solvent-free conditions, a mixture of 2,5-thiophenedicarboxaldehyde (100 mg, 0.71 mmol) and (S)-(–)-1-(4bromophenyl)ethylamine (285 mg, 1.42 mmol) in a 1:2 molar ratio were mixed at room temperature, giving a white solid. The crude was recrystallized from CH2Cl2, affording colorless crystals of the title compound. Yield 96%; m.p. 147–149 °C. Spectroscopic data: [a]D25 = +59.6 (c 1, CHCl3). IR (KBr): 1623 cm-1 (C=N). 1H NMR (400 MHz, CDCl3/TMS): δ = 1.51, 1.53 (d, 6H, CHCH3,), 4.44, 4.45, 4.47, 4.49(q, 2H, CH), 7.29–7.45 (m, 10 H, Ar), 8.36 (s, 2 H, HC=N). 13C NMR (100 MHz, CDCl3/TMS) δ = 25.1 (CCH3), 68.7 (CHCH3), 120.6 (Ar), 128.3 (Ar), 130.1 (Ar), 131.4 (Ar), 144.0 (Ar), 145.1 (Ar), 152. 7 (HC=N). MS—EI: m/z= 504 (M+). S3. Refinement The absolute configuration was determined using the anomalous dispersion of the Br atom, and was that expected from the synthesis, carried-out with an enantiomerically pure amine. All H atoms were placed in calculated positions, with C— H bond lengths fixed to 0.96 Å for the methyl group and 0.93 Å for aromatic CH groups. Isotropic displacement parameters were calculated as Uiso(H) = 1.5Ueq(carrier atom) for the methyl group and Uiso(H) = 1.2Ueq(carrier atom) otherwise. Acta Cryst. (2014). E70, o345 sup-1 supporting information Figure 1 The molecular structure of title compound, with atom labels and 30% probability displacement ellipsoids for non-H atoms. Figure 2 A packing diagram of the title compound, viewed along the b axis. 2,5-Bis{[(–)-(S)-1-(4-bromophenyl)ethyl]iminomethyl}thiophene Crystal data C22H20Br2N2S Mr = 504.27 Monoclinic, C2 Hall symbol: C 2y a = 24.5329 (15) Å b = 5.9762 (5) Å c = 7.5944 (5) Å β = 98.536 (6)° V = 1101.11 (14) Å3 Z=2 F(000) = 504 Dx = 1.521 Mg m−3 Melting point: 420 K Mo Kα radiation, λ = 0.71073 Å Cell parameters from 1609 reflections θ = 4.4–25.2° µ = 3.79 mm−1 T = 298 K Prism, colourless 0.52 × 0.15 × 0.06 mm Data collection Agilent Xcalibur (Atlas, Gemini) diffractometer Radiation source: Enhance (Mo) X-ray Source Graphite monochromator Detector resolution: 10.5564 pixels mm-1 ω scans Absorption correction: numerical (CrysAlis PRO; Agilent, 2013) Tmin = 0.400, Tmax = 0.815 Acta Cryst. (2014). E70, o345 6101 measured reflections 2107 independent reflections 1630 reflections with I > 2σ(I) Rint = 0.035 θmax = 26.1°, θmin = 3.0° h = −30→30 k = −7→7 l = −9→9 sup-2 supporting information Refinement Refinement on F2 Least-squares matrix: full R[F2 > 2σ(F2)] = 0.036 wR(F2) = 0.072 S = 1.03 2107 reflections 124 parameters 1 restraint 0 constraints Hydrogen site location: inferred from neighbouring sites H-atom parameters constrained w = 1/[σ2(Fo2) + (0.0288P)2 + 0.0296P] where P = (Fo2 + 2Fc2)/3 (Δ/σ)max < 0.001 Δρmax = 0.20 e Å−3 Δρmin = −0.35 e Å−3 Absolute structure: Flack (1983), 914 Friedel pairs Absolute structure parameter: 0.011 (8) 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. Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) Br1 S1 C9 C11 H11A H11B H11C C4 C1 C6 H6 N1 C5 H5 C2 H2 C3 H3 C7 H7 C8 H8 C10 H10 x y z Uiso*/Ueq 0.15628 (2) 0.5 0.47486 (16) 0.4216 (2) 0.4194 0.4595 0.4013 0.2306 (2) 0.33894 (18) 0.3243 (2) 0.3514 0.43094 (15) 0.2703 (2) 0.2613 0.2971 (2) 0.3056 0.2431 (2) 0.2157 0.3974 (2) 0.398 0.44434 (18) 0.4339 0.4853 (2) 0.4743 0.49000 (18) 0.2196 (2) 0.0181 (7) 0.4840 (10) 0.6248 0.4499 0.4929 0.4327 (11) 0.3489 (7) 0.5418 (9) 0.6457 0.2748 (6) 0.5823 (9) 0.711 0.1997 (9) 0.0688 0.2389 (11) 0.135 0.3024 (8) 0.1616 0.0769 (7) −0.038 −0.1907 (8) −0.3205 0.61658 (7) 0.5 0.6292 (5) 1.0744 (5) 1.0129 1.1175 1.173 0.7169 (6) 0.8651 (5) 0.7670 (6) 0.7513 0.8052 (5) 0.6921 (7) 0.6253 0.8837 (6) 0.9482 0.8092 (7) 0.8218 0.9485 (5) 1.0149 0.7709 (6) 0.8414 0.5728 (7) 0.625 0.1112 (4) 0.0472 (4) 0.0427 (10) 0.0657 (13) 0.099* 0.099* 0.099* 0.0639 (15) 0.0441 (11) 0.0569 (13) 0.068* 0.0452 (9) 0.0674 (16) 0.081* 0.0603 (13) 0.072* 0.0690 (14) 0.083* 0.0501 (12) 0.06* 0.0469 (12) 0.056* 0.0540 (13) 0.065* Acta Cryst. (2014). E70, o345 sup-3 supporting information Atomic displacement parameters (Å2) Br1 S1 C9 C11 C4 C1 C6 N1 C5 C2 C3 C7 C8 C10 U11 U22 U33 U12 U13 U23 0.0529 (4) 0.0553 (11) 0.043 (2) 0.058 (3) 0.044 (3) 0.044 (3) 0.052 (3) 0.042 (2) 0.063 (4) 0.064 (4) 0.051 (3) 0.051 (3) 0.039 (3) 0.057 (3) 0.2036 (8) 0.0347 (8) 0.038 (2) 0.085 (3) 0.106 (5) 0.053 (3) 0.062 (3) 0.052 (2) 0.084 (4) 0.067 (3) 0.094 (4) 0.060 (3) 0.051 (3) 0.035 (2) 0.0729 (4) 0.0547 (10) 0.047 (2) 0.053 (2) 0.042 (2) 0.037 (2) 0.056 (3) 0.0439 (19) 0.053 (3) 0.053 (3) 0.065 (3) 0.043 (2) 0.051 (3) 0.073 (3) 0.0279 (5) 0 0.001 (2) 0.009 (3) 0.005 (3) 0.001 (2) −0.002 (3) 0.0014 (17) 0.010 (3) −0.002 (3) −0.019 (3) 0.006 (2) 0.000 (2) −0.001 (2) −0.0044 (3) 0.0179 (8) 0.0052 (18) 0.005 (2) 0.006 (2) 0.012 (2) 0.007 (2) 0.0134 (17) 0.003 (3) 0.017 (2) 0.017 (3) 0.017 (2) 0.008 (2) 0.017 (3) −0.0229 (5) 0 0.005 (2) −0.003 (3) −0.009 (3) 0.002 (2) 0.016 (3) 0.0053 (16) 0.014 (3) 0.011 (3) −0.005 (3) 0.011 (2) 0.013 (2) 0.005 (2) Geometric parameters (Å, º) Br1—C4 S1—C9i S1—C9 C9—C8 C9—C10 C11—H11A C11—H11B C11—H11C C11—C7 C4—C5 C4—C3 C1—C6 C1—C2 1.899 (5) 1.724 (4) 1.724 (4) 1.442 (6) 1.356 (6) 0.96 0.96 0.96 1.509 (7) 1.356 (7) 1.365 (7) 1.391 (6) 1.383 (7) C1—C7 C6—H6 C6—C5 N1—C7 N1—C8 C5—H5 C2—H2 C2—C3 C3—H3 C7—H7 C8—H8 C10—C10i C10—H10 1.505 (6) 0.93 1.383 (7) 1.468 (5) 1.265 (5) 0.93 0.93 1.382 (7) 0.93 0.98 0.93 1.405 (10) 0.93 C9—S1—C9i C8—C9—S1 C10—C9—S1 C10—C9—C8 H11A—C11—H11B H11A—C11—H11C H11B—C11—H11C C7—C11—H11A C7—C11—H11B C7—C11—H11C C5—C4—Br1 C5—C4—C3 C3—C4—Br1 C6—C1—C7 91.4 (3) 121.6 (3) 111.2 (3) 127.1 (4) 109.5 109.5 109.5 109.5 109.5 109.5 119.5 (4) 121.3 (5) 119.2 (4) 122.2 (4) C4—C5—H5 C6—C5—H5 C1—C2—H2 C3—C2—C1 C3—C2—H2 C4—C3—C2 C4—C3—H3 C2—C3—H3 C11—C7—H7 C1—C7—C11 C1—C7—H7 N1—C7—C11 N1—C7—C1 N1—C7—H7 120.3 120.3 119 122.0 (5) 119 118.9 (5) 120.6 120.6 108.5 113.2 (4) 108.5 109.9 (4) 108.2 (3) 108.5 Acta Cryst. (2014). E70, o345 sup-4 supporting information C2—C1—C6 C2—C1—C7 C1—C6—H6 C5—C6—C1 C5—C6—H6 C8—N1—C7 C4—C5—C6 116.9 (4) 120.9 (4) 119.3 121.3 (5) 119.3 116.7 (3) 119.5 (5) C9—C8—H8 N1—C8—C9 N1—C8—H8 C9—C10—C10i C9—C10—H10 C10i—C10—H10 117.9 124.1 (4) 117.9 113.1 (3) 123.5 123.5 Br1—C4—C5—C6 Br1—C4—C3—C2 S1—C9—C8—N1 S1—C9—C10—C10i C9i—S1—C9—C8 C9i—S1—C9—C10 C1—C6—C5—C4 C1—C2—C3—C4 C6—C1—C2—C3 C6—C1—C7—C11 C6—C1—C7—N1 C5—C4—C3—C2 179.2 (4) −179.2 (4) 4.2 (6) 1.2 (7) −177.3 (4) −0.4 (3) 1.0 (7) −1.0 (7) −0.2 (7) 57.3 (5) −64.8 (5) 2.3 (7) C2—C1—C6—C5 C2—C1—C7—C11 C2—C1—C7—N1 C3—C4—C5—C6 C7—C1—C6—C5 C7—C1—C2—C3 C7—N1—C8—C9 C8—C9—C10—C10i C8—N1—C7—C11 C8—N1—C7—C1 C10—C9—C8—N1 0.2 (7) −122.6 (5) 115.3 (4) −2.3 (8) −179.6 (4) 179.7 (4) 176.9 (4) 177.9 (5) 131.9 (4) −104.0 (4) −172.2 (5) Symmetry code: (i) −x+1, y, −z+1. Acta Cryst. (2014). E70, o345 sup-5