Crystal structure of bis-{N'-[(E)-4-hy-droxy-benzyl-idene]pyridine-4-carbohydrazide-κN1}di-iodidocadmium methanol disolvate.

In the title compound, [Cd(C13H11IN3O2)2]·2CH3OH, which crystallizes with Z = 4 in the space group Pbcn, the CdII atom is located on a twofold rotation axis and coordinated by two I- anions and two N atoms from the pyridine rings of the two N'-[(E)-4-hy-droxy-benzyl-idene]pyridine-4-carbohydrazide ligands. The geometry around the CdII atom is distorted tetra-hedral, with bond angles in the range 94.92 (11)-124.29 (2)°. The iodide anions undergo inter-molecular hydrogen-bonding contacts with the C-H groups of the organic ligands of an adjacent complex mol-ecule, generating a chain structure along the b axis. Furthermore, an extensive series of O-H⋯O, N-H⋯O and C-H⋯O hydrogen-bonding inter-actions involving both the complex mol-ecules and the ethanol solvate mol-ecules generate a three-dimensional network.

Chemical context

Hydrazones are organic compounds that incorporate –NH–N=CH– units in their mol­ecules. Hydrazone ligands based on pyridine are among the most important classes of flexible and versatile polydentate ligands and usually act as chelating ligands to metal cations (Afkhami et al., 2016 ▸), but in some cases they behave as monodentate ligands through the pyridine group alone. The hydrazone-based ligand in the title compound was prepared according to a method reported in the literature (Deng et al., 2005 ▸). The crystal structure of the ligand and three of its ZnII metal complexes have been reported previously (Mahmoudi et al., 2016 ▸). However, the title compound is the first reported crystal structure of a CdII complex of the ligand.

Structural commentary

The mol­ecular structure of the title compound is shown in Fig. 1 ▸. The Cd atom, located on a twofold rotation axis, is coordinated by two Schiff base ligands, acting as monodentate ligands, through the nitro­gen atoms of the pyridine rings. The angle between the benzene and pyridine rings is 35.42 (19)°. The Cd—I distance is 2.6909 (5) Å and the Cd—N distance is 2.297 (3) Å. All bonds and angles in the title compound fall within acceptable ranges and are comparable with those reported for related structures of bis­{2-[(2,4-di­methyl­phen­yl)imino­meth­yl]pyridine-κ2 N,N′}bis­(thio­cyanato-κN)cadmium (Malekshahian et al., 2012 ▸), di-μ-chlorido-bis­(chlorido­{N-[phen­yl(pyridin-2-yl-κN)methyl­idene]pyridine-2-carbohydrazide-κ2 N,O}cadmium) (Akkurt et al., 2014 ▸) and cis-di­aqua­bis[(E)-4-(2-hy­droxy­benzyl-idene­amino)­benzoato-κ2 O,O′]cadmium in which layers are built from strong O—H⋯O hydrogen bonding (Yao et al., 2006 ▸).

Figure 1

The molecular components of the title compound, showing the atom-numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level [symmetry code: (a) −x, y, −z + ].

Supra­molecular features

In the crystal, the iodide anions form inter­molecular C1—H1⋯I1 hydrogen-bonding contacts with the C—H groups of the pyridine rings of an adjacent complex mol­ecule. This generates a a chain structure along the b axis. In addition, an extensive series of O—H⋯O, N—H⋯O and C—H⋯O hydrogen-bonding inter­actions, Table 1 ▸, involving both the complex mol­ecules and the methanol solvate mol­ecules, generates a three-dimensional network (Figs. 2 ▸, 3 ▸ and 4 ▸).

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2N⋯O3	0.77 (5)	2.09 (5)	2.849 (4)	174 (4)
O2—H2O⋯O1ii	0.81 (3)	1.89 (4)	2.656 (4)	159 (5)
O3—H3O⋯O2iii	0.80 (3)	2.03 (2)	2.828 (5)	173 (4)
C4—H4⋯O3	0.94	2.58	3.291 (5)	133
C7—H7⋯O3	0.94	2.56	3.327 (5)	140
C1—H1⋯I1iv	0.94	3.11	3.811 (4)	133

Symmetry codes: (ii) ; (iii) ; (iv) .

Figure 2

View of the hydrogen bonding and packing of the title compound along the a axis.

Figure 3

View of the hydrogen bonding and packing of the title compound along the b axis.

Figure 4

View of the hydrogen bonding and packing of the title compound along the c axis.

Synthesis and crystallization

The title compound was synthesized by the reaction of a methanol solution of the ligand and Cd(NO3)2·4H2O in the presence of excess amount of NaI. The ligand (1 mmol, 0.240 g) and cadmium nitrate (1 mmol, 0.308 g) were placed in the main arm of a branched tube; sodium iodide (2 mmol, 0.300 g) was added to the mixture too. Methanol was carefully added to fill the arms. The tube was sealed and the ligand-containing arm was immersed in an oil bath at 333 K while the branched arm was kept at ambient temperature. After 24 h, suitable single crystals had deposited in the cooler arm which were isolated and air dried.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. All C-bound H atoms were ideal­ized (C—H = 0.98–0.99 Å) and refined using the riding-model approximation with U iso(H) = 1.2 or 1.5 U eq(C). The N—H and O—H hydrogen atoms were located from difference maps and refined with the restraints N2—H2N = 0.77 (5), O2—H2O = 0.81 (3), O3—H3O = 0.80 (3) Å and with U iso(H) = 1.2U eq(N) or U iso(H) = 1.5U eq(O).

Table 2

Experimental details

Crystal data
Chemical formula	[Cd(C13H11IN3O2)2]·2CH4O
M r	912.79
Crystal system, space group	Orthorhombic, P b c n
Temperature (K)	213
a, b, c (Å)	8.0245 (4), 13.2482 (9), 30.4540 (19)
V (Å3)	3237.6 (3)
Z	4
Radiation type	Mo Kα
μ (mm−1)	2.63
Crystal size (mm)	0.5 × 0.3 × 0.3
Data collection
Diffractometer	Stoe IPDS1
Absorption correction	Numerical (X-RED32; Stoe & Cie, 2000 ▸)
T min, T max	0.337, 0.453
No. of measured, independent and observed [I > 2σ(I)] reflections	3511, 3511, 2542
(sin θ/λ)max (Å−1)	0.651
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.040, 0.094, 0.88
No. of reflections	3511
No. of parameters	206
No. of restraints	2
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	1.68, −1.47

Computer programs: EXPOSE, CELL, SELECT and INTEGRATE (Stoe & Cie, 2000 ▸), SHELXT2014 (Sheldrick, 2015a ▸), SHELXL2014 (Sheldrick, 2015b ▸), ORTEP-3 for Windows and WinGX (Farrugia, 2012 ▸) and PLATON (Spek, 2009 ▸).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989016019575/sj5516sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989016019575/sj5516Isup2.hkl

CCDC reference: 1521096

Additional supporting information: crystallographic information; 3D view; checkCIF report

[CdI2(C13H11N3O2)2]·2CH4O	F(000) = 1768
Mr = 912.79	Dx = 1.873 Mg m−3
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 428 reflections
a = 8.0245 (4) Å	θ = 2.9–27.6°
b = 13.2482 (9) Å	µ = 2.63 mm−1
c = 30.4540 (19) Å	T = 213 K
V = 3237.6 (3) Å3	Prism, colorless
Z = 4	0.5 × 0.3 × 0.3 mm

Stoe IPDS1 diffractometer	3511 independent reflections
Radiation source: fine-focus sealed tube	2542 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.000
phi scan	θmax = 27.6°, θmin = 2.9°
Absorption correction: numerical Stoe XRED32 (Stoe & Cie, 2000)	h = 0→9
Tmin = 0.337, Tmax = 0.453	k = 0→17
3511 measured reflections	l = 0→39

Refinement on F2	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.040	w = 1/[σ2(Fo2) + (0.0655P)2] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.094	(Δ/σ)max < 0.001
S = 0.88	Δρmax = 1.68 e Å−3
3511 reflections	Δρmin = −1.47 e Å−3
206 parameters	Extinction correction: SHELXL-2014 (Sheldrick, 2015b), Fc*=kFc[1+0.001XFc2λ3/sin(2θ)]-1/4
2 restraints	Extinction coefficient: 0.0026 (2)

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > 2sigma(F2) is used only for calculating -R-factor-obs 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
I1	−0.24029 (5)	0.11226 (3)	0.20424 (2)	0.0555 (1)
Cd1	0.00000	0.20717 (2)	0.25000	0.0250 (1)
O1	0.3473 (4)	0.62436 (18)	0.12617 (10)	0.0359 (9)
O2	1.0000 (4)	0.70774 (18)	−0.10066 (9)	0.0310 (8)
N1	0.1497 (5)	0.3244 (2)	0.21085 (10)	0.0284 (10)
N2	0.5039 (5)	0.4973 (2)	0.09734 (10)	0.0263 (9)
N3	0.5712 (5)	0.5598 (2)	0.06532 (10)	0.0269 (10)
C1	0.0746 (6)	0.4087 (3)	0.19639 (12)	0.0295 (11)
C2	0.1550 (5)	0.4791 (3)	0.17078 (12)	0.0280 (11)
C3	0.3166 (5)	0.4612 (2)	0.15733 (12)	0.0247 (10)
O3	0.6488 (4)	0.3011 (2)	0.09399 (12)	0.0431 (11)
C4	0.3962 (6)	0.3747 (3)	0.17287 (13)	0.0302 (11)
C5	0.3096 (6)	0.3093 (3)	0.19927 (13)	0.0319 (13)
C6	0.3943 (5)	0.5354 (2)	0.12611 (12)	0.0262 (10)
C7	0.6539 (5)	0.5138 (3)	0.03593 (12)	0.0265 (10)
C8	0.7372 (5)	0.5675 (3)	−0.00022 (11)	0.0244 (10)
C9	0.7230 (5)	0.6713 (3)	−0.00636 (13)	0.0290 (13)
C10	0.8101 (6)	0.7194 (3)	−0.03945 (13)	0.0293 (13)
C11	0.9119 (5)	0.6642 (2)	−0.06770 (11)	0.0230 (10)
C12	0.9264 (6)	0.5601 (3)	−0.06211 (12)	0.0263 (10)
C13	0.8388 (5)	0.5132 (3)	−0.02870 (12)	0.0268 (13)
C14	0.5662 (7)	0.2065 (3)	0.09320 (17)	0.0450 (16)
H1	−0.03730	0.42000	0.20410	0.0350*
H2	0.10030	0.53890	0.16250	0.0340*
H2N	0.541 (6)	0.444 (4)	0.0984 (14)	0.0320*
H2O	0.967 (7)	0.765 (2)	−0.1033 (17)	0.0460*
H4	0.50760	0.36150	0.16530	0.0360*
H5	0.36440	0.25140	0.20980	0.0380*
H7	0.66220	0.44310	0.03730	0.0320*
H9	0.65340	0.70910	0.01220	0.0350*
H10	0.80070	0.78960	−0.04290	0.0350*
H12	0.99500	0.52210	−0.08090	0.0320*
H13	0.84820	0.44290	−0.02520	0.0320*
H3O	0.748 (3)	0.294 (5)	0.095 (2)	0.0650*
H14A	0.62690	0.15860	0.11120	0.0670*
H14B	0.56100	0.18190	0.06320	0.0670*
H14C	0.45410	0.21430	0.10460	0.0670*

	U11	U22	U33	U12	U13	U23
I1	0.0416 (3)	0.0625 (2)	0.0624 (2)	−0.0191 (2)	0.0021 (2)	−0.0255 (2)
Cd1	0.0250 (2)	0.0179 (2)	0.0320 (2)	0.0000	0.0051 (2)	0.0000
O1	0.041 (2)	0.0198 (12)	0.0469 (16)	0.0042 (12)	0.0127 (14)	0.0091 (11)
O2	0.0326 (17)	0.0217 (11)	0.0386 (13)	0.0017 (13)	0.0098 (13)	0.0098 (10)
N1	0.035 (2)	0.0209 (13)	0.0292 (16)	0.0023 (13)	0.0071 (14)	0.0038 (12)
N2	0.031 (2)	0.0184 (12)	0.0294 (14)	0.0000 (14)	0.0067 (15)	0.0076 (11)
N3	0.027 (2)	0.0232 (13)	0.0306 (16)	−0.0034 (13)	0.0036 (14)	0.0093 (12)
C1	0.027 (2)	0.0294 (18)	0.0321 (19)	0.0061 (16)	0.0084 (16)	0.0039 (14)
C2	0.028 (2)	0.0216 (16)	0.0345 (19)	0.0068 (15)	0.0037 (16)	0.0054 (14)
C3	0.028 (2)	0.0198 (15)	0.0264 (17)	−0.0006 (14)	0.0006 (15)	0.0019 (12)
O3	0.031 (2)	0.0273 (14)	0.071 (2)	0.0040 (13)	0.0092 (16)	0.0070 (14)
C4	0.024 (2)	0.0267 (18)	0.040 (2)	0.0058 (15)	0.0078 (17)	0.0102 (15)
C5	0.034 (3)	0.0256 (18)	0.036 (2)	0.0079 (16)	0.0064 (17)	0.0066 (15)
C6	0.026 (2)	0.0202 (16)	0.0323 (18)	0.0002 (14)	−0.0008 (16)	0.0055 (13)
C7	0.028 (2)	0.0210 (16)	0.0304 (18)	−0.0032 (15)	0.0004 (16)	0.0062 (14)
C8	0.026 (2)	0.0224 (15)	0.0249 (16)	−0.0054 (15)	−0.0014 (15)	0.0041 (13)
C9	0.027 (3)	0.0241 (17)	0.0360 (19)	0.0039 (15)	0.0084 (16)	0.0031 (14)
C10	0.031 (3)	0.0180 (16)	0.039 (2)	0.0031 (15)	0.0057 (17)	0.0062 (14)
C11	0.022 (2)	0.0199 (15)	0.0271 (17)	−0.0009 (14)	−0.0007 (15)	0.0050 (13)
C12	0.032 (2)	0.0184 (15)	0.0285 (17)	0.0034 (15)	0.0018 (16)	0.0005 (13)
C13	0.033 (3)	0.0164 (15)	0.0310 (18)	−0.0025 (15)	−0.0038 (16)	0.0022 (13)
C14	0.044 (3)	0.036 (2)	0.055 (3)	−0.003 (2)	−0.003 (2)	0.003 (2)

I1—Cd1	2.6909 (5)	C8—C13	1.391 (5)
Cd1—I1i	2.6909 (5)	C8—C9	1.393 (6)
Cd1—N1	2.297 (3)	C9—C10	1.382 (6)
Cd1—N1i	2.297 (3)	C10—C11	1.394 (5)
O1—C6	1.237 (4)	C11—C12	1.395 (5)
O2—C11	1.357 (4)	C12—C13	1.384 (6)
N1—C1	1.343 (5)	C1—H1	0.9400
N1—C5	1.346 (6)	C2—H2	0.9400
N2—N3	1.389 (4)	O3—H3O	0.80 (3)
N2—C6	1.340 (5)	C4—H4	0.9400
O2—H2O	0.81 (3)	C5—H5	0.9400
N3—C7	1.270 (5)	C7—H7	0.9400
C1—C2	1.376 (6)	C9—H9	0.9400
C2—C3	1.380 (6)	C10—H10	0.9400
N2—H2N	0.77 (5)	C12—H12	0.9400
C3—C4	1.395 (5)	C13—H13	0.9400
C3—C6	1.503 (5)	C14—H14A	0.9700
O3—C14	1.418 (5)	C14—H14B	0.9700
C4—C5	1.371 (6)	C14—H14C	0.9700
C7—C8	1.471 (5)
I1—Cd1—N1	114.95 (8)	O2—C11—C12	117.9 (3)
I1—Cd1—I1i	124.29 (2)	O2—C11—C10	122.6 (3)
I1—Cd1—N1i	102.12 (9)	C10—C11—C12	119.5 (3)
I1i—Cd1—N1	102.12 (9)	C11—C12—C13	119.4 (4)
N1—Cd1—N1i	94.92 (11)	C8—C13—C12	121.6 (4)
I1i—Cd1—N1i	114.95 (8)	N1—C1—H1	119.00
Cd1—N1—C1	119.9 (3)	C2—C1—H1	119.00
Cd1—N1—C5	122.3 (2)	C1—C2—H2	120.00
C1—N1—C5	117.7 (3)	C3—C2—H2	120.00
N3—N2—C6	119.3 (3)	C14—O3—H3O	111 (5)
C11—O2—H2O	108 (4)	C5—C4—H4	121.00
N2—N3—C7	114.3 (3)	C3—C4—H4	120.00
N1—C1—C2	122.6 (4)	N1—C5—H5	119.00
C1—C2—C3	119.5 (4)	C4—C5—H5	119.00
C6—N2—H2N	125 (3)	C8—C7—H7	119.00
N3—N2—H2N	115 (3)	N3—C7—H7	119.00
C2—C3—C4	118.1 (3)	C8—C9—H9	120.00
C2—C3—C6	117.7 (3)	C10—C9—H9	120.00
C4—C3—C6	124.2 (4)	C11—C10—H10	120.00
C3—C4—C5	119.1 (4)	C9—C10—H10	120.00
N1—C5—C4	122.9 (4)	C11—C12—H12	120.00
N2—C6—C3	116.1 (3)	C13—C12—H12	120.00
O1—C6—C3	119.7 (3)	C8—C13—H13	119.00
O1—C6—N2	124.0 (3)	C12—C13—H13	119.00
N3—C7—C8	122.2 (4)	O3—C14—H14A	110.00
C7—C8—C9	122.7 (3)	O3—C14—H14B	109.00
C7—C8—C13	118.9 (4)	O3—C14—H14C	109.00
C9—C8—C13	118.4 (3)	H14A—C14—H14B	110.00
C8—C9—C10	120.8 (4)	H14A—C14—H14C	109.00
C9—C10—C11	120.3 (4)	H14B—C14—H14C	109.00
I1—Cd1—N1—C1	66.6 (3)	C2—C3—C6—O1	27.7 (5)
I1i—Cd1—N1—C1	−156.1 (3)	C2—C3—C4—C5	2.5 (6)
N1i—Cd1—N1—C1	−39.2 (3)	C6—C3—C4—C5	−176.2 (4)
I1—Cd1—N1—C5	−109.3 (3)	C2—C3—C6—N2	−147.5 (4)
I1i—Cd1—N1—C5	28.1 (3)	C4—C3—C6—O1	−153.5 (4)
N1i—Cd1—N1—C5	144.9 (3)	C3—C4—C5—N1	0.4 (6)
C1—N1—C5—C4	−1.5 (6)	N3—C7—C8—C9	−4.1 (6)
Cd1—N1—C1—C2	−176.4 (3)	N3—C7—C8—C13	173.8 (4)
C5—N1—C1—C2	−0.4 (6)	C7—C8—C9—C10	176.7 (4)
Cd1—N1—C5—C4	174.5 (3)	C13—C8—C9—C10	−1.2 (6)
C6—N2—N3—C7	−170.1 (4)	C7—C8—C13—C12	−177.1 (4)
N3—N2—C6—O1	0.2 (6)	C9—C8—C13—C12	0.9 (6)
N3—N2—C6—C3	175.1 (3)	C8—C9—C10—C11	1.0 (6)
N2—N3—C7—C8	−178.8 (4)	C9—C10—C11—O2	−180.0 (4)
N1—C1—C2—C3	3.3 (6)	C9—C10—C11—C12	−0.5 (6)
C1—C2—C3—C6	174.6 (3)	O2—C11—C12—C13	179.8 (4)
C1—C2—C3—C4	−4.3 (5)	C10—C11—C12—C13	0.3 (6)
C4—C3—C6—N2	31.2 (5)	C11—C12—C13—C8	−0.5 (6)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2N···O3	0.77 (5)	2.09 (5)	2.849 (4)	174 (4)
O2—H2O···O1ii	0.81 (3)	1.89 (4)	2.656 (4)	159 (5)
O3—H3O···O2iii	0.80 (3)	2.03 (2)	2.828 (5)	173 (4)
C4—H4···O3	0.94	2.58	3.291 (5)	133
C7—H7···O3	0.94	2.56	3.327 (5)	140
C1—H1···I1iv	0.94	3.11	3.811 (4)	133