(1Z,1′Z,3E,3′E)-1,1′-Diphenyl-3,3′-[(1S,2S)-cyclo­hexane-1,2-diyldinitrilo]dibut-1-en-1-ol

Xiu-Zhi Li; Zhi-Rong Qu

doi:10.1107/S1600536808014670

. 2008 May 21;64(Pt 6):o1121. doi: 10.1107/S1600536808014670

(1Z,1′Z,3E,3′E)-1,1′-Diphenyl-3,3′-[(1S,2S)-cyclohexane-1,2-diyldinitrilo]dibut-1-en-1-ol

Xiu-Zhi Li ^a, Zhi-Rong Qu ^a,^*

PMCID: PMC2961585 PMID: 21202632

Abstract

A new tetradentate chiral Schiff base ligand, C₂₆H₃₀N₂O₂, has been synthesized by the reaction of 1-phenylbutane-1,3-dione with (1S,2S)-(−)-1,2-diaminocyclohexane. The chiral centers in the molecule have the same S configuration, since the absolute configuration was determined by that of the starting reagent (1S,2S)-(−)-1,2-diaminohexane. The cyclohexane ring is in a chair conformation, and the substituents are equatorial in the most stable conformation (trans-cyclohexyl). The crystal structure is stabilized by two intramolecular O—H⋯N hydrogen bonds and a weak C—H⋯π interaction.

Related literature

For the chemistry of Schiff bases, see: Alemi & Shaabani (2000 ▶); Bandini et al. (1999 ▶, 2000 ▶); Belokon et al. (1997 ▶); Cozzi (2003 ▶); Jiang et al. (1995 ▶); Kureshy et al. (2001 ▶); Sasaki et al. (1991 ▶).

Experimental

Crystal data

C₂₆H₃₀N₂O₂
M _r = 402.52
Orthorhombic,
a = 8.9073 (11) Å
b = 10.1205 (13) Å
c = 26.476 (3) Å
V = 2386.7 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 293 (2) K
0.20 × 0.20 × 0.20 mm

Data collection

Rigaku SCXmini diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.980, T _max = 0.990
22130 measured reflections
2683 independent reflections
1952 reflections with I > 2σ(I)
R _int = 0.062

Refinement

R[F ² > 2σ(F ²)] = 0.061
wR(F ²) = 0.159
S = 1.07
2683 reflections
275 parameters
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808014670/bx2143sup1.cif

e-64-o1121-sup1.cif^{(22.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808014670/bx2143Isup2.hkl

e-64-o1121-Isup2.hkl^{(131.8KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2A⋯N2	0.82	1.93	2.650 (3)	146
O1—H1⋯N1	0.82	1.91	2.629 (4)	145
C19—H19A⋯Cg3ⁱ	0.97	2.96	3.795 (5)	144

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Symmetry code: (i) Inline graphic . Cg3 is the centroid of the C10–C15 ring.

Acknowledgments

This work was supported by a Start-up Grant from Southeast University to ZRQ.

supplementary crystallographic information

Comment

In recent years, research on Schiff bases has been intensified for the reason that some of them can form materials with non-linear optical (NLO) activity (Alemi & Shaabani, 2000), and some can be used for the asymmetric oxidation of methyl phenyl sulfides (Sasaki et al., 1991). The search for new chiral ligands for asymmetric synthesis is an important task in organic chemistry. Various chiral Schiff bases are widely used in asymmetric reactions (Jiang et al., 1995; Belokon et al., 1997; Bandini et al., 1999, 2000; Kureshy et al., 2001; Cozzi, 2003). Herein, we report the synthesis and crystal structure of a new chiral Schiff base ligand (1Z,1'Z,3E,3'E)-3,3'-((1S,2S)-cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene))bis(1-phenylbut-1-en-1-ol). Fig. 1 show, the absolute configurations of the chiral centers and they have the same chirality (S-configuration). The cyclohexane ring is of chair conformation, and the substituents are equatorial in the most stable conformation of trans-cyclohexyl. The crystal structure is stabilized by two intramolecular O—H···N hydrogen bonds and a weak C—H···π interaction (Table 1).

Experimental

1-phenylbutane-1,3-dione (3.89 g, 0.024 mol) in 6 ml of chloroform was added dropwise to a solution of chloroform (20 ml) containing (1S, 2S)-(–)-1,2-diaminocyclohexane (1.14 g, 0.01 mol), which was kept at 0–5°C with vigorous stirring during the reaction. After complete addition which took approximately 30 min, the mixture was stirred for another 1 h at room temperature. After the evaporation of the solvent under reduced pressure, the crude product was recrystallized by slowly evaporating with petroleum ether to yield colorless crystals.