(E,E)-2,2′-[1,1′-(Cyclohexane-1,2-diyl­dinitrilo)diethylidyne]diphenol

Fang Chen; Heng-Yun Ye

doi:10.1107/S160053680802552X

. 2008 Aug 16;64(Pt 9):o1757. doi: 10.1107/S160053680802552X

(E,E)-2,2′-[1,1′-(Cyclohexane-1,2-diyldinitrilo)diethylidyne]diphenol

Fang Chen ^a, Heng-Yun Ye ^a,^*

PMCID: PMC2960556 PMID: 21201739

Abstract

The title compound, C₂₂H₂₆N₂O₂, is chiral; the absolute configuration follows from the known chirality of the input reagents. The asymmetric unit contains two crystallographically independent molecules in different orientations. The two molecules are related to each other by a non-crystallographic twofold rotation axis, while each molecule exhibits a further pseudo-twofold axis. Bond distances and angles are similar in the two molecules. Intermolecular C—H⋯π(ring) interactions and intramolecular O—H⋯N hydrogen bonds are observed in the crystal structure.

Related literature

For examples of syntheses of non-centrosymmetric solid materials by reaction of chiral organic ligands and inorganic salts, see: Qu et al. (2004 ▶). For related structures, see: Figuet et al. (2001 ▶); Kennedy & Reglinski (2001 ▶); Thamotharan et al. (2003 ▶).

Experimental

Crystal data

C₂₂H₂₆N₂O₂
M _r = 350.45
Monoclinic,
a = 12.608 (3) Å
b = 11.185 (2) Å
c = 14.438 (3) Å
β = 106.14 (3)°
V = 1955.8 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 (2) K
0.25 × 0.15 × 0.15 mm

Data collection

Rigaku SCXmini diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.839, T _max = 1.000 (expected range = 0.829–0.989)
20307 measured reflections
4712 independent reflections
2978 reflections with I > 2σ(I)
R _int = 0.079

Refinement

R[F ² > 2σ(F ²)] = 0.057
wR(F ²) = 0.134
S = 1.04
4712 reflections
473 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.21 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: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680802552X/ez2132sup1.cif

e-64-o1757-sup1.cif^{(28.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680802552X/ez2132Isup2.hkl

e-64-o1757-Isup2.hkl^{(230.8KB, hkl)}

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

Table 1. Selected torsion angles (°).

N1—C1—C6—N2	−69.1 (3)
N3—C28—C23—N4	−65.9 (3)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1	0.82	1.77	2.496 (4)	147
O2—H2⋯N2	0.82	1.81	2.531 (4)	147
O3—H3⋯N3	0.82	1.82	2.507 (4)	140
O4—H4⋯N4	0.82	1.78	2.507 (4)	147
C26—H26A⋯Cg3ⁱ	0.97	2.96	3.790 (5)	144
C29—H29C⋯Cg3ⁱⁱ	0.96	2.96	3.721 (5)	137
C37—H37C⋯Cg3ⁱⁱⁱ	0.96	3.00	3.714 (4)	133

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) . Cg3 is the centroid of the C17–C22 ring and Cg2 is the centroid of the C9–C14 ring.

Acknowledgments

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

supplementary crystallographic information

Comment

The existence of a chiral centre in an organic ligand is very important for the construction of noncentrosymmetric or chiral coordination polymers that exhibit desirable physical properties such as ferroelectric behavior (Qu et al., 2004). As a part of our ongoing investigations in this field we have determined the crystal structure of the title compound, (I).

Fig. 1 shows the asymmetric unit consisting of two molecules of (I). The two crystallographically independent molecules have the same geometrical parameters within the precision of the experiments. The bond lengths and angles in (I) are comparable to the corresponding values in the related structures, tris[(5-bromosalicylidene)aminoethyl]amine (Figuet et al., 2001), N,N'-bis(salicylidene)-1,4-butanediamine (Kennedy & Reglinski, 2001) and N-(4-Butylphenyl)salicylaldimine (Thamotharan et al., 2003). The average for the N1—C1—C6—N2 and N3—C28—C23—N4 torsion angles is 67.5 (3)°, the average dihedral angle between two benzene rings within one molecule is 48.0 (1)°, and the average distance between the centers of the two benzene rings is 6.53 Å. Like other Schiff base compounds containing salicylidene (Figuet et al., 2001; Kennedy & Reglinski, 2001; Thamotharan et al., 2003) the hydroxyl groups form intramolecular hydrogen bonds with the N atoms (Table 2), thereby completing six-membered rings.

Experimental

o-Hydroxyacetophenone (0.68 g, 5.0 mmol) and (1R,2R)-(-)-diaminocyclohexane (0.30 g, 2.6 mmol) were dissolved in ethanol (30 mL), and heated to reflux for 8 h until the raw material disappeared according to TLC detection. The solution was cooled to room temperature, then solvent was removed under reduced pressure. The residue was recrystallized with iso-propanol to afford yellow crystals, some of which were suitable for X-ray analysis.