6,6'-Diethoxy-2,2'-[2,2-dimethylpropane-1,3-diylbis(nitrilomethylidyne)]diphenol.

In the crystal structure, the title Schiff base compound, C(23)H(30)N(2)O(4), exhibits crystallographic twofold rotation symmetry. The imino group is coplanar with the aromatic ring with an N-C-C-C torsion angle of -179.72 (9)°. An intra-molecular O-H⋯N hydrogen bond forms a six-membered ring, producing an S(6) ring motif. The dihedral angle between symmetry related benzene rings is 28.05 (5)°. The eth-oxy group makes a C-O-C-C torsion angle of -7.20 (16)° with the benzene ring. The crystal structure is stabilized by inter-molecular C-H⋯π inter-actions.

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For information on Schiff base ligands, complexes and their applications, see, for example: Calligaris & Randaccio, (1987 ▶); Casellato & Vigato, (1977 ▶); Pal et al. (2005 ▶); Reglinski et al. 2004 ▶; Hou et al. (2001 ▶); Ren et al. (2002 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C23H30N2O4

M = 398.49

Monoclinic,

a = 5.6523 (1) Å

b = 12.9591 (2) Å

c = 28.3771 (3) Å

β = 91.282 (1)°

V = 2078.07 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 100 K

0.43 × 0.22 × 0.04 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (; Bruker, 2005 ▶) T min = 0.880, T max = 0.997

21349 measured reflections

3560 independent reflections

2743 reflections with I > 2σ(I)

R int = 0.042

Refinement

R[F 2 > 2σ(F 2)] = 0.045

wR(F 2) = 0.128

S = 1.07

3560 reflections

134 parameters

H-atom parameters constrained

Δρmax = 0.42 e Å−3

Δρmin = −0.26 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809007557/at2735sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809007557/at2735Isup2.hkl

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

C23H30N2O4	F(000) = 856
Mr = 398.49	Dx = 1.274 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 5303 reflections
a = 5.6523 (1) Å	θ = 2.9–31.8°
b = 12.9591 (2) Å	µ = 0.09 mm−1
c = 28.3771 (3) Å	T = 100 K
β = 91.282 (1)°	Plate, yellow
V = 2078.07 (5) Å3	0.43 × 0.22 × 0.04 mm
Z = 4

Bruker SMART APEXII CCD area-detector diffractometer	3560 independent reflections
Radiation source: fine-focus sealed tube	2743 reflections with I > 2σ(I)
graphite	Rint = 0.042
φ and ω scans	θmax = 31.8°, θmin = 1.4°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −8→8
Tmin = 0.880, Tmax = 0.997	k = −18→19
21349 measured reflections	l = −42→41

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.128	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.0621P)2 + 0.9557P] where P = (Fo2 + 2Fc2)/3
3560 reflections	(Δ/σ)max = 0.001
134 parameters	Δρmax = 0.42 e Å−3
0 restraints	Δρmin = −0.26 e Å−3

Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.

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.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

	x	y	z	Uiso*/Ueq
O2	−0.21577 (13)	0.86647 (6)	0.42709 (3)	0.01900 (18)
O1	0.07879 (14)	0.77817 (6)	0.36945 (3)	0.01951 (18)
H1	0.1800	0.7580	0.3514	0.029*
N1	0.44608 (15)	0.78978 (7)	0.31751 (3)	0.01556 (18)
C1	0.11143 (18)	0.87962 (8)	0.37834 (4)	0.0150 (2)
C2	−0.04483 (18)	0.92916 (8)	0.40916 (4)	0.0157 (2)
C3	−0.01574 (19)	1.03346 (8)	0.41899 (4)	0.0180 (2)
H3A	−0.1215	1.0665	0.4386	0.022*
C4	0.1713 (2)	1.08960 (8)	0.39974 (4)	0.0189 (2)
H4A	0.1897	1.1593	0.4066	0.023*
C5	0.32737 (19)	1.04064 (8)	0.37052 (4)	0.0168 (2)
H5A	0.4531	1.0774	0.3582	0.020*
C6	0.29882 (18)	0.93596 (8)	0.35912 (3)	0.01445 (19)
C7	0.46777 (18)	0.88493 (8)	0.32869 (3)	0.0151 (2)
H7A	0.5941	0.9225	0.3172	0.018*
C8	0.62015 (17)	0.74010 (8)	0.28797 (4)	0.0149 (2)
H8A	0.7249	0.6980	0.3075	0.018*
H8B	0.7150	0.7925	0.2729	0.018*
C9	0.5000	0.67209 (11)	0.2500	0.0132 (3)
C10	0.68697 (18)	0.60294 (9)	0.22779 (4)	0.0175 (2)
H10A	0.7602	0.5606	0.2518	0.026*
H10B	0.8049	0.6451	0.2134	0.026*
H10C	0.6130	0.5597	0.2043	0.026*
C11	−0.36178 (19)	0.90890 (9)	0.46303 (4)	0.0181 (2)
H11A	−0.4504	0.9675	0.4508	0.022*
H11B	−0.2647	0.9318	0.4896	0.022*
C12	−0.5284 (2)	0.82495 (9)	0.47814 (4)	0.0215 (2)
H12A	−0.6358	0.8522	0.5007	0.032*
H12B	−0.4392	0.7694	0.4921	0.032*
H12C	−0.6163	0.7998	0.4512	0.032*

	U11	U22	U33	U12	U13	U23
O2	0.0195 (4)	0.0172 (4)	0.0207 (4)	−0.0019 (3)	0.0086 (3)	−0.0030 (3)
O1	0.0212 (4)	0.0142 (4)	0.0235 (4)	−0.0046 (3)	0.0087 (3)	−0.0061 (3)
N1	0.0162 (4)	0.0165 (4)	0.0141 (4)	−0.0009 (3)	0.0029 (3)	−0.0018 (3)
C1	0.0177 (5)	0.0132 (5)	0.0141 (4)	−0.0009 (3)	0.0004 (3)	−0.0010 (3)
C2	0.0165 (4)	0.0159 (5)	0.0147 (4)	−0.0005 (4)	0.0022 (3)	−0.0001 (4)
C3	0.0221 (5)	0.0157 (5)	0.0163 (5)	0.0017 (4)	0.0026 (4)	−0.0015 (4)
C4	0.0249 (5)	0.0128 (5)	0.0190 (5)	0.0002 (4)	0.0010 (4)	−0.0003 (4)
C5	0.0200 (5)	0.0142 (5)	0.0164 (4)	−0.0018 (4)	0.0009 (4)	0.0012 (4)
C6	0.0164 (4)	0.0144 (5)	0.0126 (4)	−0.0006 (3)	0.0008 (3)	0.0004 (3)
C7	0.0155 (4)	0.0166 (5)	0.0134 (4)	−0.0022 (3)	0.0014 (3)	0.0017 (3)
C8	0.0132 (4)	0.0160 (5)	0.0154 (4)	−0.0011 (3)	0.0029 (3)	−0.0002 (3)
C9	0.0132 (6)	0.0131 (6)	0.0134 (6)	0.000	0.0034 (5)	0.000
C10	0.0174 (5)	0.0168 (5)	0.0186 (5)	0.0039 (4)	0.0032 (4)	−0.0005 (4)
C11	0.0194 (5)	0.0196 (5)	0.0157 (4)	0.0015 (4)	0.0051 (4)	−0.0012 (4)
C12	0.0191 (5)	0.0243 (6)	0.0213 (5)	0.0011 (4)	0.0060 (4)	0.0020 (4)

O2—C2	1.3692 (12)	C7—H7A	0.9300
O2—C11	1.4357 (12)	C8—C9	1.5382 (13)
O1—C1	1.3506 (12)	C8—H8A	0.9700
O1—H1	0.8200	C8—H8B	0.9700
N1—C7	1.2784 (13)	C9—C10	1.5319 (13)
N1—C8	1.4568 (13)	C9—C10i	1.5319 (13)
C1—C6	1.4065 (14)	C9—C8i	1.5382 (13)
C1—C2	1.4112 (14)	C10—H10A	0.9600
C2—C3	1.3890 (15)	C10—H10B	0.9600
C3—C4	1.4039 (15)	C10—H10C	0.9600
C3—H3A	0.9300	C11—C12	1.5075 (16)
C4—C5	1.3789 (15)	C11—H11A	0.9700
C4—H4A	0.9300	C11—H11B	0.9700
C5—C6	1.4031 (14)	C12—H12A	0.9600
C5—H5A	0.9300	C12—H12B	0.9600
C6—C7	1.4601 (14)	C12—H12C	0.9600
C2—O2—C11	117.29 (8)	N1—C8—H8B	109.4
C1—O1—H1	109.5	C9—C8—H8B	109.4
C7—N1—C8	120.45 (9)	H8A—C8—H8B	108.0
O1—C1—C6	122.26 (9)	C10—C9—C10i	108.40 (12)
O1—C1—C2	118.29 (9)	C10—C9—C8i	110.18 (6)
C6—C1—C2	119.43 (9)	C10i—C9—C8i	108.99 (6)
O2—C2—C3	125.73 (9)	C10—C9—C8	108.99 (6)
O2—C2—C1	114.65 (9)	C10i—C9—C8	110.18 (6)
C3—C2—C1	119.62 (9)	C8i—C9—C8	110.08 (12)
C2—C3—C4	120.85 (10)	C9—C10—H10A	109.5
C2—C3—H3A	119.6	C9—C10—H10B	109.5
C4—C3—H3A	119.6	H10A—C10—H10B	109.5
C5—C4—C3	119.54 (10)	C9—C10—H10C	109.5
C5—C4—H4A	120.2	H10A—C10—H10C	109.5
C3—C4—H4A	120.2	H10B—C10—H10C	109.5
C4—C5—C6	120.77 (10)	O2—C11—C12	107.36 (9)
C4—C5—H5A	119.6	O2—C11—H11A	110.2
C6—C5—H5A	119.6	C12—C11—H11A	110.2
C5—C6—C1	119.75 (9)	O2—C11—H11B	110.2
C5—C6—C7	120.06 (9)	C12—C11—H11B	110.2
C1—C6—C7	120.16 (9)	H11A—C11—H11B	108.5
N1—C7—C6	121.55 (9)	C11—C12—H12A	109.5
N1—C7—H7A	119.2	C11—C12—H12B	109.5
C6—C7—H7A	119.2	H12A—C12—H12B	109.5
N1—C8—C9	111.29 (7)	C11—C12—H12C	109.5
N1—C8—H8A	109.4	H12A—C12—H12C	109.5
C9—C8—H8A	109.4	H12B—C12—H12C	109.5
C11—O2—C2—C3	−7.20 (15)	O1—C1—C6—C5	−178.44 (10)
C11—O2—C2—C1	172.54 (8)	C2—C1—C6—C5	−0.41 (15)
O1—C1—C2—O2	0.25 (14)	O1—C1—C6—C7	−0.50 (15)
C6—C1—C2—O2	−177.86 (9)	C2—C1—C6—C7	177.53 (9)
O1—C1—C2—C3	180.00 (9)	C8—N1—C7—C6	−178.59 (9)
C6—C1—C2—C3	1.89 (15)	C5—C6—C7—N1	−179.73 (10)
O2—C2—C3—C4	177.87 (10)	C1—C6—C7—N1	2.34 (15)
C1—C2—C3—C4	−1.86 (15)	C7—N1—C8—C9	−136.31 (10)
C2—C3—C4—C5	0.31 (16)	N1—C8—C9—C10	−166.89 (8)
C3—C4—C5—C6	1.21 (16)	N1—C8—C9—C10i	−48.07 (11)
C4—C5—C6—C1	−1.15 (15)	N1—C8—C9—C8i	72.16 (7)
C4—C5—C6—C7	−179.09 (9)	C2—O2—C11—C12	−178.04 (9)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.82	1.85	2.5772 (12)	147
C11—H11A···Cg1ii	0.96	2.87	3.6007 (12)	133

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1	0.82	1.85	2.5772 (12)	147
C11—H11A⋯Cg1i	0.96	2.87	3.6007 (12)	133

Symmetry code: (i) . Cg1 is the centroid of the C1–C6 benzene ring.