2,2'-Dihydroxy-3,3'-[(1E,1'E)-hydrazine-1,2-diylidenedimethylidyne]dibenzoic acid N,N-dimethylformamide disolvate.

The title compound, C(16)H(12)N(2)O(6)·2C(3)H(7)NO, lies across a crystallographic inversion centre which is situated at the midpoint of the central N-N bond. The substitution at the C=N bond adopts a trans configuration and it is essentially coplanar with the benzene ring [N-C-C-C torsion angles = -173.9 (4) and 6.4 (6)°]. All torsion angles involving non-H atoms are close to 180°. Intra-molecular O-H⋯O and weak C-H⋯O hydrogen bonds form S(6) and S(5) ring motifs, respectively, while inter-molecular O-H⋯O and weak C-H⋯O hydrogen bonds connect the Schiff base mol-ecule to solvent dimethyl-formamide mol-ecules.

Related literature

For information on Schiff base ligands, their complexes and their applications, see, for example: Pal et al. (2005 ▶); Hou et al. (2001 ▶); Ren et al. (2002 ▶). For bond-length data, see: Allen et al. (1987 ▶). For the structures and properties of related azine organic and metallorganic compounds, see, for example: Dreuw et al. (2005 ▶); Chattopadhyay et al. (2008 ▶); Cucos et al. (2006 ▶); Fu (2007 ▶); Mijanuddina et al. (2004 ▶); Sreerama et al. (2007 ▶); Butcher et al. (2007 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C16H12N2O6·2C3H7NO

M = 474.47

Monoclinic,

a = 5.9136 (12) Å

b = 10.837 (2) Å

c = 18.991 (4) Å

β = 98.96 (3)°

V = 1202.2 (4) Å3

Z = 2

Mo Kα radiation

μ = 0.10 mm−1

T = 295 K

0.36 × 0.20 × 0.16 mm

Data collection

Bruker SMART CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.965, T max = 0.984

7616 measured reflections

1978 independent reflections

679 reflections with I > 2σ(I)

R int = 0.082

Refinement

R[F 2 > 2σ(F 2)] = 0.067

wR(F 2) = 0.149

S = 1.01

1978 reflections

159 parameters

H-atom parameters constrained

Δρmax = 0.14 e Å−3

Δρmin = −0.14 e Å−3

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); 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/S1600536808043134/lh2745sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808043134/lh2745Isup2.hkl

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

C16H12N2O6·2C3H7NO	F(000) = 500
Mr = 474.47	Dx = 1.311 Mg m−3
Monoclinic, P21/c	Melting point: 443 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 5.9136 (12) Å	Cell parameters from 812 reflections
b = 10.837 (2) Å	θ = 2.1–15.4°
c = 18.991 (4) Å	µ = 0.10 mm−1
β = 98.96 (3)°	T = 295 K
V = 1202.2 (4) Å3	Needle, red
Z = 2	0.36 × 0.20 × 0.16 mm

Bruker SMART CCD area-detector diffractometer	1978 independent reflections
Radiation source: fine-focus sealed tube	679 reflections with I > 2σ(I)
graphite	Rint = 0.082
φ and ω scans	θmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −6→7
Tmin = 0.965, Tmax = 0.984	k = −12→12
7616 measured reflections	l = −22→22

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.067	H-atom parameters constrained
wR(F2) = 0.149	w = 1/[σ2(Fo2) + (0.036P)2 + 0.022P] where P = (Fo2 + 2Fc2)/3
S = 1.01	(Δ/σ)max < 0.001
1978 reflections	Δρmax = 0.14 e Å−3
159 parameters	Δρmin = −0.13 e Å−3
0 restraints	Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.016 (4)

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	0.9469 (6)	0.9471 (3)	0.51035 (19)	0.0850 (12)
N2	0.2954 (7)	0.6509 (3)	0.23059 (19)	0.0830 (11)
O1	−0.0194 (5)	0.7647 (3)	0.34383 (15)	0.0925 (10)
O2	−0.0718 (5)	0.5919 (3)	0.40230 (16)	0.0978 (10)
H2	−0.1983	0.5948	0.3775	0.147*
O3	0.3501 (5)	0.8896 (3)	0.37878 (14)	0.0913 (10)
H3	0.2293	0.8697	0.3541	0.137*
O4	0.5660 (5)	0.5621 (3)	0.31107 (17)	0.1024 (11)
C1	0.2520 (8)	0.7119 (4)	0.4437 (2)	0.0735 (12)
C2	0.3105 (8)	0.6335 (4)	0.5012 (2)	0.0901 (14)
H2A	0.2151	0.5678	0.5079	0.108*
C3	0.5105 (10)	0.6525 (5)	0.5488 (2)	0.1046 (16)
H3A	0.5491	0.6001	0.5877	0.126*
C4	0.6512 (8)	0.7496 (5)	0.5380 (2)	0.0977 (16)
H4	0.7858	0.7614	0.5698	0.117*
C5	0.5984 (8)	0.8308 (4)	0.4808 (2)	0.0753 (13)
C6	0.3970 (8)	0.8102 (4)	0.4342 (2)	0.0717 (12)
C7	0.0427 (8)	0.6924 (5)	0.3928 (3)	0.0782 (13)
C8	0.7514 (9)	0.9333 (4)	0.4714 (2)	0.0829 (13)
H8	0.7050	0.9909	0.4357	0.099*
C9	0.4849 (9)	0.6507 (5)	0.2750 (3)	0.0863 (14)
H9	0.5674	0.7240	0.2801	0.104*
C10	0.1512 (9)	0.5403 (4)	0.2220 (2)	0.1212 (18)
H10A	0.2158	0.4811	0.1933	0.182*
H10B	0.0001	0.5622	0.1993	0.182*
H10C	0.1433	0.5052	0.2680	0.182*
C11	0.2066 (9)	0.7591 (5)	0.1912 (3)	0.1217 (18)
H11A	0.3080	0.8274	0.2039	0.183*
H11B	0.0579	0.7784	0.2024	0.183*
H11C	0.1949	0.7432	0.1410	0.183*

	U11	U22	U33	U12	U13	U23
N1	0.066 (3)	0.093 (3)	0.091 (3)	0.006 (2)	0.000 (2)	−0.007 (2)
N2	0.079 (3)	0.082 (3)	0.085 (3)	−0.017 (2)	0.005 (2)	−0.005 (2)
O1	0.093 (2)	0.093 (2)	0.084 (2)	0.0066 (18)	−0.0070 (18)	0.0125 (17)
O2	0.089 (2)	0.093 (2)	0.107 (3)	−0.003 (2)	0.0012 (19)	0.0162 (19)
O3	0.096 (2)	0.094 (2)	0.079 (2)	−0.0056 (18)	−0.0022 (17)	0.0103 (17)
O4	0.098 (3)	0.085 (2)	0.116 (3)	−0.001 (2)	−0.010 (2)	0.0036 (19)
C1	0.071 (3)	0.078 (3)	0.072 (3)	0.009 (3)	0.014 (3)	0.000 (3)
C2	0.092 (4)	0.098 (3)	0.080 (3)	0.001 (3)	0.015 (3)	0.008 (3)
C3	0.104 (4)	0.124 (4)	0.080 (3)	0.018 (4)	−0.003 (3)	0.022 (3)
C4	0.085 (4)	0.119 (4)	0.082 (4)	0.009 (3)	−0.009 (3)	0.005 (3)
C5	0.083 (3)	0.077 (3)	0.063 (3)	0.021 (3)	0.002 (3)	−0.008 (3)
C6	0.078 (3)	0.075 (3)	0.062 (3)	0.021 (3)	0.011 (3)	0.001 (2)
C7	0.075 (3)	0.069 (3)	0.090 (4)	0.013 (3)	0.012 (3)	−0.006 (3)
C8	0.089 (4)	0.079 (3)	0.082 (3)	0.020 (3)	0.018 (3)	−0.009 (2)
C9	0.076 (4)	0.090 (4)	0.094 (4)	−0.012 (3)	0.014 (3)	−0.007 (3)
C10	0.126 (5)	0.116 (4)	0.123 (4)	−0.042 (4)	0.023 (4)	−0.037 (3)
C11	0.118 (4)	0.118 (4)	0.120 (4)	−0.009 (3)	−0.008 (3)	0.023 (3)

N1—C8	1.281 (5)	C2—H2A	0.9300
N1—N1i	1.393 (6)	C3—C4	1.377 (6)
N2—C9	1.293 (5)	C3—H3A	0.9300
N2—C11	1.445 (5)	C4—C5	1.395 (5)
N2—C10	1.465 (5)	C4—H4	0.9300
O1—C7	1.228 (5)	C5—C6	1.387 (5)
O2—C7	1.310 (5)	C5—C8	1.462 (6)
O2—H2	0.8200	C8—H8	0.9300
O3—C6	1.354 (4)	C9—H9	0.9300
O3—H3	0.8200	C10—H10A	0.9600
O4—C9	1.232 (5)	C10—H10B	0.9600
C1—C2	1.384 (5)	C10—H10C	0.9600
C1—C6	1.397 (5)	C11—H11A	0.9600
C1—C7	1.462 (5)	C11—H11B	0.9600
C2—C3	1.388 (6)	C11—H11C	0.9600
C8—N1—N1i	109.8 (5)	C5—C6—C1	121.6 (4)
C9—N2—C11	123.2 (4)	O1—C7—O2	122.3 (4)
C9—N2—C10	120.1 (4)	O1—C7—C1	122.1 (5)
C11—N2—C10	116.6 (4)	O2—C7—C1	115.6 (4)
C7—O2—H2	109.5	N1—C8—C5	122.5 (4)
C6—O3—H3	109.5	N1—C8—H8	118.7
C2—C1—C6	119.1 (4)	C5—C8—H8	118.7
C2—C1—C7	121.0 (5)	O4—C9—N2	125.9 (5)
C6—C1—C7	119.9 (4)	O4—C9—H9	117.0
C1—C2—C3	120.4 (5)	N2—C9—H9	117.0
C1—C2—H2A	119.8	N2—C10—H10A	109.5
C3—C2—H2A	119.8	N2—C10—H10B	109.5
C4—C3—C2	119.3 (4)	H10A—C10—H10B	109.5
C4—C3—H3A	120.4	N2—C10—H10C	109.5
C2—C3—H3A	120.4	H10A—C10—H10C	109.5
C3—C4—C5	122.1 (5)	H10B—C10—H10C	109.5
C3—C4—H4	118.9	N2—C11—H11A	109.5
C5—C4—H4	118.9	N2—C11—H11B	109.5
C6—C5—C4	117.5 (5)	H11A—C11—H11B	109.5
C6—C5—C8	122.0 (4)	N2—C11—H11C	109.5
C4—C5—C8	120.5 (4)	H11A—C11—H11C	109.5
O3—C6—C5	116.5 (5)	H11B—C11—H11C	109.5
O3—C6—C1	121.9 (4)
C6—C1—C2—C3	0.1 (6)	C2—C1—C6—C5	0.3 (6)
C7—C1—C2—C3	179.5 (4)	C7—C1—C6—C5	−179.2 (4)
C1—C2—C3—C4	−0.5 (7)	C2—C1—C7—O1	175.7 (4)
C2—C3—C4—C5	0.6 (8)	C6—C1—C7—O1	−4.9 (6)
C3—C4—C5—C6	−0.3 (7)	C2—C1—C7—O2	−5.4 (6)
C3—C4—C5—C8	179.5 (4)	C6—C1—C7—O2	174.1 (4)
C4—C5—C6—O3	−179.5 (4)	N1i—N1—C8—C5	−179.4 (4)
C8—C5—C6—O3	0.7 (6)	C6—C5—C8—N1	−173.9 (4)
C4—C5—C6—C1	−0.2 (6)	C4—C5—C8—N1	6.4 (6)
C8—C5—C6—C1	−180.0 (4)	C11—N2—C9—O4	178.3 (5)
C2—C1—C6—O3	179.5 (4)	C10—N2—C9—O4	2.7 (7)
C7—C1—C6—O3	0.1 (6)

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9···O1ii	0.93	2.59	3.261 (6)	130
C2—H2A···O2	0.93	2.43	2.742 (6)	99
O3—H3···O1	0.82	1.85	2.568 (4)	146
O2—H2···O4iii	0.82	1.76	2.557 (4)	162

Table 1

Selected torsion angles (°)

C7—C1—C2—C3	179.5 (4)
C3—C4—C5—C8	179.5 (4)
C4—C5—C6—O3	−179.5 (4)
C8—C5—C6—C1	−180.0 (4)
C7—C1—C6—C5	−179.2 (4)
C6—C1—C7—O2	174.1 (4)
N1i—N1—C8—C5	−179.4 (4)
C6—C5—C8—N1	−173.9 (4)
C11—N2—C9—O4	178.3 (5)

Symmetry code: (i) .

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C9—H9⋯O1ii	0.93	2.59	3.261 (6)	130
C2—H2A⋯O2	0.93	2.43	2.742 (6)	99
O3—H3⋯O1	0.82	1.85	2.568 (4)	146
O2—H2⋯O4iii	0.82	1.76	2.557 (4)	162

Symmetry codes: (ii) ; (iii) .