organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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2,5-Bis{[(–)-(S)-1-(4-methyl­phen­yl)eth­yl]imino­meth­yl}thio­phene

aDEP Facultad de Ciencias Químicas, UANL, Guerrero y Progreso S/N, Col. Treviño, 64570 Monterrey, NL, Mexico, bLaboratorio de Síntesis de Complejos, Facultad de Ciencias Químicas, Universidad Autónoma de Puebla, PO Box 156, 72001 Puebla, Pue., Mexico, and cIngeniería Bioquímica, Instituto Tecnológico Superior de Atlixco, 74218 Atlixco, Pue., Mexico
*Correspondence e-mail: sylvain_bernes@Hotmail.com

(Received 17 July 2013; accepted 2 August 2013; online 14 August 2013)

The title chiral bis-aldimine, C24H26N2S, was synthesized using a solvent-free Schiff condensation. The mol­ecule displays crystallographic C2 symmetry, with the S atom lying on the twofold axis parallel to [100]. As a consequence of the (S,S) stereochemistry, the tolyl groups are oriented towards opposite faces of the thiophene core, giving a twisted conformation for the whole mol­ecule. Mol­ecules are arranged in the crystal in a herringbone-like pattern, without any significant inter­molecular contacts.

Related literature

For the solvent-free approach in organic synthesis, see: Tanaka & Toda (2000[Tanaka, K. & Toda, F. (2000). Chem. Rev. 100, 1025-1074.]). For the structure of a chiral bis-aldimine compound, see: Espinosa Leija et al. (2009[Espinosa Leija, A., Bernès, S., Hernández, G., Sharma, P., Peña, U. & Gutiérrez, R. (2009). Acta Cryst. E65, o2317.]). For structures of thio­phenes substituted in positions 2 and 5 by imine functionalities, see: Skene & Dufresne (2006[Skene, W. G. & Dufresne, S. (2006). Acta Cryst. E62, o1116-o1117.]); Fridman & Kaftory (2007[Fridman, N. & Kaftory, M. (2007). Pol. J. Chem. 81, 825-832.]); de Lima et al. (2010[Lima, G. M. de, Harrison, W. T. A., Tiekink, E. R. T., Wardell, J. L. & Wardell, S. M. S. V. (2010). Acta Cryst. E66, o504-o505.]); Kudyakova et al. (2011[Kudyakova, Yu. S., Burgart, Ya. V. & Saloutin, V. I. (2011). Chem. Heterocycl. Compd, 47, 558-563.], 2012[Kudyakova, Y. S., Burgart, Y. V., Slepukhin, P. A. & Saloutin, V. I. (2012). Mendeleev Commun. 22, 284-286.]).

[Scheme 1]

Experimental

Crystal data
  • C24H26N2S

  • Mr = 374.53

  • Orthorhombic, P 221 21

  • a = 6.278 (3) Å

  • b = 7.900 (3) Å

  • c = 21.500 (7) Å

  • V = 1066.4 (7) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.16 mm−1

  • T = 298 K

  • 0.50 × 0.32 × 0.10 mm

Data collection
  • Bruker P4 diffractometer

  • Absorption correction: ψ scan (XSCANS; Siemens, 1996[Siemens (1996). XSCANS. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]) Tmin = 0.754, Tmax = 0.985

  • 3046 measured reflections

  • 1767 independent reflections

  • 1352 reflections with I > 2σ(I)

  • Rint = 0.066

  • 3 standard reflections every 97 reflections intensity decay: 2.5%

Refinement
  • R[F2 > 2σ(F2)] = 0.052

  • wR(F2) = 0.155

  • S = 1.06

  • 1767 reflections

  • 125 parameters

  • H-atom parameters constrained

  • Δρmax = 0.22 e Å−3

  • Δρmin = −0.26 e Å−3

  • Absolute structure: Flack x determined using 412 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons & Flack, 2004[Parsons, S. & Flack, H. (2004). Acta Cryst. A60, s61.])

  • Absolute structure parameter: −0.08 (18)

Data collection: XSCANS (Siemens, 1996[Siemens (1996). XSCANS. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]); software used to prepare material for publication: SHELXL2013.

Supporting information


Comment top

In the last few years, our attention has been focused on the synthesis and structure of chiral bis-imines (e.g. Espinosa Leija et al., 2009), mostly due to their versatile coordination behavior and interesting properties as ligands for building of chiral metal complexes. Along this line, the title compound was synthesized through a Schiff condensation between a low-melting point dialdehyde and a liquid amine having a high boiling-point (above 200 °C), which also serves as a solvent for the reaction. No other solvents were used for the reaction (Tanaka & Toda, 2000).

The crude compound crystallized from CH2Cl2, allowing to determine its chiral purity and crystal structure. The obtained bis-aldimine is the expected (S,S) diastereoisomer, with imine bonds in the common E configuration (Fig. 1). The molecule is placed on the 2-fold axis of space group P22121, with the S atom lying on the symmetry axis. The resulting molecular conformation displays the C2 symmetry, with imine arms oriented towards opposite sides of the central thiophene core ring. Other thiophenes substituted in positions 2 and 5 by imine groups have been characterized (e.g. Skene & Dufresne, 2006; Fridman & Kaftory, 2007; de Lima et al., 2010; Kudyakova et al., 2011, 2012). However, all were achiral compounds, and only one actually presented a crystallographic C2 symmetry (space group C2/c, Kudyakova et al., 2011), as in the title compound.

The molecules are arranged in the crystal in such a way they form a herringbone-like structure (Fig. 2). However, no actual supramolecular pattern is formed in the solid-state, since no intermolecular contacts of significant strength are present.

Related literature top

For the solvent-free approach in 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: Skene & Dufresne (2006); Fridman & Kaftory (2007); de Lima et al. (2010); Kudyakova et al. (2011, 2012).

Experimental top

Under solvent-free conditions, a mixture of 2,5-thiophenedicarboxaldehyde (100 mg, 0.71 mmol) and (S)-(–)-1-(4-methylphenyl)ethylamine (192 mg, 1.42 mmol) in a 1:2 molar ratio were mixed at room temperature, giving a brownish solid. The crude was recrystallized from CH2Cl2, affording colorless crystals of the title compound, in 91% yield. M.p. 150–152 °C. Spectroscopic data: [α]25D = +59.9 (c 1, CHCl3). IR (KBr): 1624 cm-1 (CN). 1H-NMR (400 MHz, CDCl3/TMS, p.p.m.): δ = 1.54–1.55 (d, 6H, CHCH3), 2.33 (s, 6H, PhCH3), 4.46, 4.51 (q, 2H, CH), 7.13–7.29 (m, 10H, Ar), 8.34 (s, 2H, HCN). 13C-NMR (100 MHz, CDCl3/TMS, p.p.m.): δ = 21.0 (CCH3), 30.9 (PhCH3), 69.0 (CHCH3), 126.5 (Ar), 129.0 (Ar), 129.7 (Ar), 136.4 (Ar), 141.9 (Ar), 145.1 (Ar), 152.2 (HCN). MS—EI: m/z = 374 (M+).

Refinement top

All C-bonded H atoms were placed in idealized positions and refined as riding to their carrier C atoms, with bond lengths fixed to 0.93 (aromatic CH), 0.96 (methyl CH3), and 0.98 Å (methine CH). Isotropic displacement parameters were calculated as Uiso(H) = 1.5Ueq(C7, C14) for methyl groups and Uiso(H) = 1.2Ueq(carrier C) for other H atoms. The absolute configuration was assigned from the known configuration of the chiral amine used as starting material. The absolute structure was confirmed through the Parsons-Flack test (Parsons & Flack, 2004).

Computing details top

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS (Siemens, 1996); data reduction: XSCANS (Siemens, 1996); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2013 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The title molecule with displacement ellipsoids for non-H atoms shown at the 50% probability level. The asymmetric unit consists of half of the molecule, and symmetry code to generate equivalent atoms is i = x, 1 - y, 2 - z.
[Figure 2] Fig. 2. Part of the crystal structure, viewed along the a-axis.
2,5-Bis{[(-)-(S)-1-(4-methylphenyl)ethyl]iminomethyl}thiophene top
Crystal data top
C24H26N2SDx = 1.166 Mg m3
Mr = 374.53Melting point: 423 K
Orthorhombic, P22121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2bc 2Cell parameters from 71 reflections
a = 6.278 (3) Åθ = 4.2–12.3°
b = 7.900 (3) ŵ = 0.16 mm1
c = 21.500 (7) ÅT = 298 K
V = 1066.4 (7) Å3Plate, colourless
Z = 20.50 × 0.32 × 0.10 mm
F(000) = 400
Data collection top
Bruker P4
diffractometer
1352 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.066
Graphite monochromatorθmax = 25.1°, θmin = 1.9°
2θ/ω scansh = 75
Absorption correction: ψ scan
(XSCANS; Siemens, 1996)
k = 99
Tmin = 0.754, Tmax = 0.985l = 2525
3046 measured reflections3 standard reflections every 97 reflections
1767 independent reflections intensity decay: 2.5%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.052H-atom parameters constrained
wR(F2) = 0.155 w = 1/[σ2(Fo2) + (0.0559P)2 + 0.760P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max < 0.001
1767 reflectionsΔρmax = 0.22 e Å3
125 parametersΔρmin = 0.26 e Å3
0 restraintsAbsolute structure: Flack x determined using 412 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons & Flack, 2004)
0 constraintsAbsolute structure parameter: 0.08 (18)
Primary atom site location: structure-invariant direct methods
Crystal data top
C24H26N2SV = 1066.4 (7) Å3
Mr = 374.53Z = 2
Orthorhombic, P22121Mo Kα radiation
a = 6.278 (3) ŵ = 0.16 mm1
b = 7.900 (3) ÅT = 298 K
c = 21.500 (7) Å0.50 × 0.32 × 0.10 mm
Data collection top
Bruker P4
diffractometer
1352 reflections with I > 2σ(I)
Absorption correction: ψ scan
(XSCANS; Siemens, 1996)
Rint = 0.066
Tmin = 0.754, Tmax = 0.9853 standard reflections every 97 reflections
3046 measured reflections intensity decay: 2.5%
1767 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.052H-atom parameters constrained
wR(F2) = 0.155Δρmax = 0.22 e Å3
S = 1.06Δρmin = 0.26 e Å3
1767 reflectionsAbsolute structure: Flack x determined using 412 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons & Flack, 2004)
125 parametersAbsolute structure parameter: 0.08 (18)
0 restraints
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
S10.6440 (3)0.50001.00000.0580 (5)
C20.8347 (8)0.3700 (6)0.9686 (2)0.0536 (12)
C31.0327 (8)0.4251 (7)0.9825 (2)0.0645 (15)
H3B1.15620.36960.97010.077*
C40.7765 (9)0.2268 (7)0.9303 (2)0.0579 (13)
H4A0.88340.15350.91720.069*
N50.5897 (7)0.1971 (6)0.91410 (19)0.0578 (11)
C60.5569 (9)0.0468 (7)0.8745 (2)0.0651 (15)
H6B0.69510.00640.85940.078*
C70.4544 (14)0.0898 (8)0.9141 (3)0.099 (2)
H7B0.54850.11960.94760.148*
H7C0.42710.18790.88900.148*
H7D0.32260.04830.93090.148*
C80.4176 (8)0.0904 (6)0.8199 (2)0.0540 (12)
C90.2393 (8)0.1892 (7)0.8261 (2)0.0605 (14)
H9B0.20740.23690.86450.073*
C100.1074 (9)0.2188 (8)0.7765 (3)0.0665 (14)
H10A0.01320.28550.78220.080*
C110.1489 (9)0.1524 (7)0.7186 (3)0.0627 (13)
C120.3281 (10)0.0573 (7)0.7125 (2)0.0697 (15)
H12D0.36180.01330.67360.084*
C130.4616 (9)0.0235 (8)0.7617 (2)0.0657 (14)
H13D0.58120.04410.75590.079*
C140.0019 (11)0.1849 (9)0.6647 (3)0.091 (2)
H14A0.07890.17200.62650.136*
H14B0.05330.29800.66750.136*
H14C0.11380.10550.66590.136*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.0456 (10)0.0627 (11)0.0658 (10)0.0000.0000.0035 (10)
C20.051 (3)0.062 (3)0.048 (2)0.001 (3)0.001 (2)0.004 (2)
C30.046 (3)0.085 (4)0.062 (3)0.005 (3)0.002 (2)0.018 (3)
C40.056 (3)0.063 (3)0.055 (3)0.005 (3)0.002 (2)0.004 (3)
N50.059 (3)0.057 (3)0.057 (2)0.002 (2)0.007 (2)0.006 (2)
C60.068 (3)0.064 (4)0.064 (3)0.006 (3)0.017 (3)0.011 (3)
C70.151 (7)0.063 (4)0.082 (4)0.013 (4)0.040 (5)0.012 (3)
C80.055 (3)0.048 (3)0.059 (3)0.000 (2)0.001 (2)0.005 (2)
C90.056 (3)0.068 (3)0.057 (3)0.004 (3)0.006 (2)0.009 (3)
C100.056 (3)0.063 (3)0.080 (3)0.007 (3)0.000 (3)0.005 (3)
C110.064 (3)0.055 (3)0.068 (3)0.009 (3)0.010 (3)0.000 (3)
C120.080 (4)0.069 (4)0.059 (3)0.000 (3)0.002 (3)0.009 (3)
C130.064 (3)0.066 (3)0.067 (3)0.015 (3)0.003 (2)0.018 (3)
C140.098 (5)0.087 (5)0.088 (4)0.005 (4)0.032 (4)0.008 (4)
Geometric parameters (Å, º) top
S1—C21.716 (5)C8—C91.371 (7)
S1—C2i1.716 (5)C8—C131.387 (7)
C2—C31.350 (7)C9—C101.370 (7)
C2—C41.446 (7)C9—H9B0.9300
C3—C3i1.403 (10)C10—C111.377 (8)
C3—H3B0.9300C10—H10A0.9300
C4—N51.246 (6)C11—C121.359 (8)
C4—H4A0.9300C11—C141.502 (8)
N5—C61.475 (7)C12—C131.374 (8)
C6—C81.504 (7)C12—H12D0.9300
C6—C71.518 (9)C13—H13D0.9300
C6—H6B0.9800C14—H14A0.9600
C7—H7B0.9600C14—H14B0.9600
C7—H7C0.9600C14—H14C0.9600
C7—H7D0.9600
C2—S1—C2i91.5 (3)C9—C8—C6122.0 (5)
C3—C2—C4127.6 (5)C13—C8—C6120.1 (5)
C3—C2—S1111.2 (4)C10—C9—C8121.1 (5)
C4—C2—S1121.1 (4)C10—C9—H9B119.5
C2—C3—C3i113.0 (3)C8—C9—H9B119.5
C2—C3—H3B123.5C9—C10—C11121.6 (5)
C3i—C3—H3B123.5C9—C10—H10A119.2
N5—C4—C2123.0 (5)C11—C10—H10A119.2
N5—C4—H4A118.5C12—C11—C10117.0 (5)
C2—C4—H4A118.5C12—C11—C14122.0 (6)
C4—N5—C6116.4 (4)C10—C11—C14121.0 (6)
N5—C6—C8110.3 (4)C11—C12—C13122.6 (5)
N5—C6—C7107.9 (4)C11—C12—H12D118.7
C8—C6—C7110.7 (5)C13—C12—H12D118.7
N5—C6—H6B109.3C12—C13—C8119.9 (5)
C8—C6—H6B109.3C12—C13—H13D120.0
C7—C6—H6B109.3C8—C13—H13D120.0
C6—C7—H7B109.5C11—C14—H14A109.5
C6—C7—H7C109.5C11—C14—H14B109.5
H7B—C7—H7C109.5H14A—C14—H14B109.5
C6—C7—H7D109.5C11—C14—H14C109.5
H7B—C7—H7D109.5H14A—C14—H14C109.5
H7C—C7—H7D109.5H14B—C14—H14C109.5
C9—C8—C13117.8 (5)
C2i—S1—C2—C30.5 (3)C7—C6—C8—C13100.2 (6)
C2i—S1—C2—C4177.0 (5)C13—C8—C9—C100.9 (8)
C4—C2—C3—C3i176.0 (5)C6—C8—C9—C10175.9 (5)
S1—C2—C3—C3i1.3 (7)C8—C9—C10—C110.6 (9)
C3—C2—C4—N5171.3 (5)C9—C10—C11—C120.7 (9)
S1—C2—C4—N55.7 (7)C9—C10—C11—C14179.6 (6)
C2—C4—N5—C6179.4 (4)C10—C11—C12—C131.6 (9)
C4—N5—C6—C8132.6 (5)C14—C11—C12—C13178.6 (6)
C4—N5—C6—C7106.3 (6)C11—C12—C13—C81.4 (9)
N5—C6—C8—C942.7 (7)C9—C8—C13—C120.0 (8)
C7—C6—C8—C976.6 (7)C6—C8—C13—C12176.9 (5)
N5—C6—C8—C13140.5 (5)
Symmetry code: (i) x, y+1, z+2.

Experimental details

Crystal data
Chemical formulaC24H26N2S
Mr374.53
Crystal system, space groupOrthorhombic, P22121
Temperature (K)298
a, b, c (Å)6.278 (3), 7.900 (3), 21.500 (7)
V3)1066.4 (7)
Z2
Radiation typeMo Kα
µ (mm1)0.16
Crystal size (mm)0.50 × 0.32 × 0.10
Data collection
DiffractometerBruker P4
diffractometer
Absorption correctionψ scan
(XSCANS; Siemens, 1996)
Tmin, Tmax0.754, 0.985
No. of measured, independent and
observed [I > 2σ(I)] reflections
3046, 1767, 1352
Rint0.066
(sin θ/λ)max1)0.596
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.052, 0.155, 1.06
No. of reflections1767
No. of parameters125
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.22, 0.26
Absolute structureFlack x determined using 412 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons & Flack, 2004)
Absolute structure parameter0.08 (18)

Computer programs: XSCANS (Siemens, 1996), SHELXS2013 (Sheldrick, 2008), SHELXL2013 (Sheldrick, 2008), Mercury (Macrae et al., 2008).

 

Acknowledgements

Support from VIEP-UAP (GUPJ-NAT12-G) is acknowledged.

References

First citationEspinosa Leija, A., Bernès, S., Hernández, G., Sharma, P., Peña, U. & Gutiérrez, R. (2009). Acta Cryst. E65, o2317.  Web of Science CSD CrossRef IUCr Journals
First citationFridman, N. & Kaftory, M. (2007). Pol. J. Chem. 81, 825–832.  CAS
First citationKudyakova, Yu. S., Burgart, Ya. V. & Saloutin, V. I. (2011). Chem. Heterocycl. Compd, 47, 558–563.  CrossRef CAS
First citationKudyakova, Y. S., Burgart, Y. V., Slepukhin, P. A. & Saloutin, V. I. (2012). Mendeleev Commun. 22, 284–286.  Web of Science CSD CrossRef CAS
First citationLima, G. M. de, Harrison, W. T. A., Tiekink, E. R. T., Wardell, J. L. & Wardell, S. M. S. V. (2010). Acta Cryst. E66, o504–o505.  Web of Science CSD CrossRef IUCr Journals
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CrossRef CAS IUCr Journals
First citationParsons, S. & Flack, H. (2004). Acta Cryst. A60, s61.  CrossRef IUCr Journals
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationSiemens (1996). XSCANS. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.
First citationSkene, W. G. & Dufresne, S. (2006). Acta Cryst. E62, o1116–o1117.  Web of Science CSD CrossRef CAS IUCr Journals
First citationTanaka, K. & Toda, F. (2000). Chem. Rev. 100, 1025–1074.  Web of Science CrossRef PubMed CAS

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