6,6'-Dihydr-oxy-2,2'-[(butane-1,4-diyldi-oxy)bis-(nitrilo-methyl-idyne)]diphenol.

The mol-ecule of the centrosymmetric title compound, C(18)H(20)N(2)O(6), assumes an E configuration with respect to the azomethine C=N bond. The imino group is coplanar with the aromatic ring. Intra-molecular O-H⋯O and O-H⋯N bonds are found between the hydroxyl groups and adjacent O (or N) atoms. In the crystal structure, inter-molecular O-H⋯O bonds link each mol-ecule to two others, forming a layered network.

Related literature

For background information, see: Sharma (2002 ▶). For related structures, see: Fan et al. (2006 ▶); Wang et al. (2003 ▶); Akine et al. (2006 ▶). Dong et al. (2007 ▶, 2008a ▶,b ▶); Wang et al. (2007 ▶).

Experimental

Crystal data

C18H20N2O6

M = 360.36

Mmonoclinic,

a = 27.484 (3) Å

b = 4.7106 (7) Å

c = 14.0081 (19) Å

β = 104.306 (2)°

V = 1757.4 (4) Å3

Z = 4

Mo Kα radiation

μ = 0.10 mm−1

T = 298 (2) K

0.55 × 0.53 × 0.48 mm

Data collection

Siemens Smart 1000 CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.945, T max = 0.952

4086 measured reflections

1555 independent reflections

1112 reflections with I > 2σ(I)

R int = 0.026

Refinement

R[F 2 > 2σ(F 2)] = 0.035

wR(F 2) = 0.106

S = 1.10

1555 reflections

118 parameters

H-atom parameters constrained

Δρmax = 0.16 e Å−3

Δρmin = −0.15 e Å−3

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); data reduction: SAINT; 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.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808028468/fl2218sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808028468/fl2218Isup2.hkl

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

C18H20N2O6	Z = 4
Mr = 360.36	F(000) = 760
Mmonoclinic, C2/c	Dx = 1.362 Mg m−3
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 27.484 (3) Å	Cell parameters from 1695 reflections
b = 4.7106 (7) Å	θ = 2.4–27.8°
c = 14.0081 (19) Å	µ = 0.10 mm−1
α = 90°	T = 298 K
β = 104.306 (2)°	Block-shaped, pale-brown
γ = 90°	0.55 × 0.53 × 0.48 mm
V = 1757.4 (4) Å3

Bruker Smart 1000 CCD area-detector diffractometer	1555 independent reflections
Radiation source: fine-focus sealed tube	1112 reflections with I > 2σ(I)
graphite	Rint = 0.026
φ and ω scans	θmax = 25.0°, θmin = 1.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −17→32
Tmin = 0.945, Tmax = 0.952	k = −5→5
4086 measured reflections	l = −16→16

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)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.106	H-atom parameters constrained
S = 1.10	w = 1/[σ2(Fo2) + (0.0457P)2 + 0.5441P] where P = (Fo2 + 2Fc2)/3
1555 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 0.16 e Å−3
0 restraints	Δρmin = −0.16 e Å−3

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.

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 > σ(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
N1	0.08963 (5)	0.5854 (3)	0.37586 (9)	0.0445 (4)
O1	0.07135 (4)	0.7516 (3)	0.44261 (7)	0.0505 (3)
O2	0.09612 (4)	0.3675 (3)	0.20520 (8)	0.0595 (4)
H2	0.0848	0.4741	0.2407	0.089*
O3	0.14491 (5)	0.0061 (3)	0.11078 (8)	0.0719 (5)
H3	0.1213	0.1137	0.0890	0.108*
C1	0.02835 (6)	0.9102 (4)	0.39001 (12)	0.0484 (4)
H1A	0.0020	0.7819	0.3565	0.058*
H1B	0.0375	1.0312	0.3411	0.058*
C2	0.01029 (6)	1.0875 (4)	0.46377 (12)	0.0486 (5)
H2A	−0.0158	1.2150	0.4287	0.058*
H2B	0.0379	1.2027	0.5002	0.058*
C3	0.12781 (6)	0.4381 (4)	0.41858 (12)	0.0444 (4)
H3A	0.1401	0.4526	0.4865	0.053*
C4	0.15231 (5)	0.2489 (3)	0.36349 (11)	0.0396 (4)
C5	0.13584 (6)	0.2207 (4)	0.26086 (11)	0.0420 (4)
C6	0.16024 (6)	0.0352 (4)	0.21112 (12)	0.0474 (4)
C7	0.20050 (7)	−0.1205 (4)	0.26152 (13)	0.0531 (5)
H7	0.2165	−0.2451	0.2277	0.064*
C8	0.21755 (6)	−0.0930 (4)	0.36307 (13)	0.0534 (5)
H8	0.2451	−0.1977	0.3971	0.064*
C9	0.19369 (6)	0.0890 (4)	0.41324 (12)	0.0475 (4)
H9	0.2052	0.1062	0.4812	0.057*

	U11	U22	U33	U12	U13	U23
N1	0.0463 (8)	0.0494 (9)	0.0400 (7)	−0.0006 (7)	0.0146 (6)	−0.0072 (7)
O1	0.0512 (7)	0.0609 (8)	0.0389 (6)	0.0100 (6)	0.0105 (5)	−0.0093 (6)
O2	0.0598 (8)	0.0715 (9)	0.0411 (6)	0.0174 (6)	0.0011 (6)	−0.0067 (6)
O3	0.0830 (9)	0.0906 (11)	0.0404 (7)	0.0200 (8)	0.0123 (6)	−0.0101 (7)
C1	0.0467 (9)	0.0537 (11)	0.0438 (9)	0.0022 (8)	0.0094 (7)	0.0009 (8)
C2	0.0488 (10)	0.0465 (11)	0.0524 (10)	0.0047 (8)	0.0158 (8)	0.0026 (8)
C3	0.0451 (9)	0.0513 (11)	0.0359 (8)	−0.0040 (8)	0.0088 (7)	−0.0031 (8)
C4	0.0384 (8)	0.0428 (10)	0.0379 (8)	−0.0055 (7)	0.0102 (7)	−0.0011 (7)
C5	0.0396 (9)	0.0452 (10)	0.0400 (9)	−0.0013 (7)	0.0077 (7)	0.0014 (8)
C6	0.0525 (10)	0.0513 (11)	0.0405 (9)	−0.0021 (9)	0.0153 (8)	−0.0034 (8)
C7	0.0529 (10)	0.0528 (11)	0.0586 (11)	0.0045 (9)	0.0232 (9)	−0.0016 (9)
C8	0.0454 (10)	0.0570 (12)	0.0578 (11)	0.0078 (9)	0.0124 (8)	0.0099 (9)
C9	0.0448 (9)	0.0565 (11)	0.0402 (9)	−0.0010 (8)	0.0083 (7)	0.0053 (8)

N1—C3	1.277 (2)	C2—H2B	0.9700
N1—O1	1.4041 (16)	C3—C4	1.449 (2)
O1—C1	1.4377 (19)	C3—H3A	0.9300
O2—C5	1.3627 (19)	C4—C9	1.398 (2)
O2—H2	0.8200	C4—C5	1.403 (2)
O3—C6	1.3709 (19)	C5—C6	1.389 (2)
O3—H3	0.8200	C6—C7	1.369 (2)
C1—C2	1.505 (2)	C7—C8	1.389 (2)
C1—H1A	0.9700	C7—H7	0.9300
C1—H1B	0.9700	C8—C9	1.373 (2)
C2—C2i	1.521 (3)	C8—H8	0.9300
C2—H2A	0.9700	C9—H9	0.9300
C3—N1—O1	112.25 (12)	C9—C4—C5	118.48 (15)
N1—O1—C1	109.42 (11)	C9—C4—C3	119.58 (14)
C5—O2—H2	109.5	C5—C4—C3	121.94 (14)
C6—O3—H3	109.5	O2—C5—C6	116.75 (14)
O1—C1—C2	107.79 (13)	O2—C5—C4	123.26 (15)
O1—C1—H1A	110.1	C6—C5—C4	119.99 (15)
C2—C1—H1A	110.1	C7—C6—O3	118.65 (16)
O1—C1—H1B	110.1	C7—C6—C5	120.48 (15)
C2—C1—H1B	110.1	O3—C6—C5	120.87 (15)
H1A—C1—H1B	108.5	C6—C7—C8	120.18 (17)
C1—C2—C2i	113.41 (18)	C6—C7—H7	119.9
C1—C2—H2A	108.9	C8—C7—H7	119.9
C2i—C2—H2A	108.9	C9—C8—C7	119.96 (16)
C1—C2—H2B	108.9	C9—C8—H8	120.0
C2i—C2—H2B	108.9	C7—C8—H8	120.0
H2A—C2—H2B	107.7	C8—C9—C4	120.90 (16)
N1—C3—C4	121.39 (14)	C8—C9—H9	119.6
N1—C3—H3A	119.3	C4—C9—H9	119.6
C4—C3—H3A	119.3
C3—N1—O1—C1	−179.64 (14)	O2—C5—C6—C7	−179.99 (15)
N1—O1—C1—C2	−179.36 (12)	C4—C5—C6—C7	−0.2 (3)
O1—C1—C2—C2i	−66.3 (2)	O2—C5—C6—O3	0.7 (2)
O1—N1—C3—C4	179.32 (13)	C4—C5—C6—O3	−179.56 (16)
N1—C3—C4—C9	−179.32 (15)	O3—C6—C7—C8	178.97 (17)
N1—C3—C4—C5	0.8 (2)	C5—C6—C7—C8	−0.4 (3)
C9—C4—C5—O2	−179.62 (14)	C6—C7—C8—C9	0.6 (3)
C3—C4—C5—O2	0.2 (3)	C7—C8—C9—C4	−0.2 (3)
C9—C4—C5—C6	0.6 (2)	C5—C4—C9—C8	−0.4 (2)
C3—C4—C5—C6	−179.53 (15)	C3—C4—C9—C8	179.71 (15)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···N1	0.82	1.94	2.648 (2)	145.
O3—H3···O2	0.82	2.26	2.706 (2)	115.
O3—H3···O1ii	0.82	2.26	2.930 (2)	139.

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯N1	0.82	1.94	2.648 (2)	145
O3—H3⋯O2	0.82	2.26	2.706 (2)	115
O3—H3⋯O1i	0.82	2.26	2.930 (2)	139

Symmetry code: (i) .