Poly[bis(μ-4-benzoyl-1-isonicotinoyl­thio­semi­carbazide-κ²N:S)dichloridocadmium(II)]

The asymmetric unit of the title complex, [CdCl₂(C₁₄H₁₂N₄O₂S)₂]_n, consists of one Cd^II ion located on the crystallographic inversion centre, one 4-benzoyl-1-­iso­nicotinoyl­thio­semi­carbazide ligand and one chloride ligand. The central Cd^II ion adopts a distorted octa­hedral coordination geometry formed by two pyridyl N atoms of two ligands, two S atoms of two other ligands and two chloride ligands. The thio­semi­carbazide ligands act as bridges, linking the metal ions into a two-dimensional layered structure parallel to the bc plane. Inter­molecular N—H...O hydrogen bonds and C—H...π inter­actions exist between adjacent layers.

S1. Comment

Thiosemicarbazides and their derivatives have attracted considerable interest, not only because of their potentially beneficial biological properties, such as antibacterial, antitumour and antiviral activities (Angelusiu et al., 2009; Belicchi-Ferrari et al., 2007; Palaska et al., 2002), but also because of their flexibility, which allows the ligands to bend and rotate freely to accommodate the coordination geometries of various metal centres. Many metal complexes derived from thiosemicarbazone, particularly the 1,4-substituted derivatives, have been prepared and characterized, and have been found to possess a wide variety of biological activities (Floquet et al., 2009; Leovac et al., 2009; Hassanien et al., 2008; Latheef et al., 2006; Babb et al., 2003; Simonov et al., 2002; Belicchi-Ferrari et al., 2000). However, only a few 1,4-bisacylthiosemicarbazone ligands have been reported so far (Xue et al., 2006; Ali et al., 2004; Yamin & Yusof, 2003; Yusof et al., 2003). Acylthiosemicarbazide ligands contain O, S and N as potential donor atoms and can support mononuclear, multinuclear or even extended structure complexes. They can also form hydrogen bonds in the crystal structure, which is very important in the design and synthesis of novel supramolecular structures.

Recently, much attention has been paid to coordination polymers with a framework structure, because of their potential applications and theoretical significance (Uemura et al., 2009; Tranchemontagne et al., 2009; Kurmoo, 2009; Lee et al., 2009). However, there is no previous report of coordination polymers with a 1,4-bisacylthiosemicarbazone ligand. Our group reported the first transition metal complex with a 1,4-bisacylthiosemicarbazone ligand (Ke et al., 2007). That cobalt complex is mononuclear. In order to connect the metal centres to form a framework, we increased the possible donor atoms by replacing one of the phenyl groups with a pyridine ring. Here, we report the title two-dimensional coordination polymer, (I), which is the first transition metal complex with such ligands with an extended structure.

The asymmetric unit of complex (I) contains one Cd^II ion located on an inversion centre, one independent ligand and one chloride ion. The local coordination geometry around the Cd^II centre can be described as distorted octahedral (Fig. 1 and Table 1). The equatorial plane is formed by two N atoms [N4ⁱ and N4ⁱⁱ; symmetry codes: (i) -x + 1, y - 1, -z + 3/2; (ii) x, -y + 2, z - 1/2] of two pyridine rings with a Cd—N bond of 2.373 (3) Å, and two Cl^- ions [Cl1 and Cl1ⁱⁱⁱ; symmetry code: (iii) -x + 1, -y + 1, -z + 1] with a Cd—Cl bond length of 2.583 (3) Å. The axial positions are occupied by two S atoms (S1 and S1ⁱⁱⁱ) from two other ligands with a Cd—S bond of 2.736 (4) Å.

Each thiosemicarbazide ligand acts as a linear linker to coordinate two metal centers, while each metal ion is linked by four ligands and two chloride ligands in a trans configuration. Thus, twodimensional undulating layers are formed parallel to the bc plane (Fig. 2). The benzoyl groups are located on both sides of the layers. There are three types of intralayer hydrogen bonds, namely N1—H1···Cl1, N3—H3···Cl1 and N2—H10···O1 while there is one type of interlayer hydrogen bond. Neighboring layers are further connected to each other via N2—H10···O1 hydrogen bonds [N2···O1 = 3.010 (3) Å and N2—H10···O1 = 141°] and C6—H6···π interactions [C6···pyridyl = 3.327 (4) Å and C6—H6···Cg = 122°] (Fig. 3 and Table 2).

Compared with the previously reported cobalt complex (Ke et al., 2007), in this cadmium polymer the ligands coordinate to the Cd^II ions with atoms N4 and S1 in a bridging motif, and the structure is characterized by a two-dimensional architecture. The dihedral angle between the phenyl and pyridyl groups is 39.46 (9)°. However, in the previously reported complex, the tridentate ligands coordinate to the Co^II centre through one N atom and two carbonyl O atoms in a chelating mode and the complex presents a mononuclear structure. The dihedral angles between the two phenyl groups are 28.03 (1) and 10.38 (2)°. The discrepancy indicates that 1,4-bisacylthiosemicarbazone ligands have varied coordination motifs.

S2. Experimental

The ligand was prepared following the procedure described by Xue et al. (2006). The ligand (0.0189 g, 0.10 mmol) and cadmium chloride hydrate (0.0115 g, 0.05 mmol) were dissolved in a mixed solvent of methanol and N,N-dimethylformamide (11 ml, 10:1 v/v). After 5 min, dichloromethane (2 ml) was added and the solution was then stirred for 3 h at room temperature. Colourless cube-shaped crystals of (I) crystallized from the solvent mixture after about 10 d.

S3. Refinement

All H atoms bonded to C and N atoms were allowed for in idealized positions using the riding-model approximation, with C—H = 0.93 Å and U_iso(H) = 1.2Ueq(C), and N—H = 0.86 Å and U_iso(H) = 1.2Ueq(N).

Computing details

Data collection: CrystalClear (Rigaku, 2002); cell refinement: CrystalClear (Rigaku, 2002); data reduction: CrystalClear (Rigaku, 2002); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The structure of (I), showing the atom-labelling scheme and 30% probability displacement ellipsoids. H atoms have been omitted for clarity. [Symmetry codes: (i) -x + 1, y - 1, -z + 3/2; (ii) x, -y + 2, z - 1/2; (iii) -x + 1, -y + 1, -z + 1.] [Symops have been swapped to match order in text and table - please check]
	Fig. 2. A view of the two-dimensional layer in (I).
	Fig. 3. A packing diagram for (I), with hydrogen bonds shown as dashed lines.

Poly[bis(µ-4-benzoyl-1-isonicotinoylthiosemicarbazide- κ²N:S)dichloridocadmium(II)]

Crystal data

[CdCl2(C14H12N4O2S)2]	F(000) = 1576
Mr = 783.97	Dx = 1.711 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 26.272 (5) Å	θ = 12–18°
b = 8.8773 (18) Å	µ = 1.08 mm^−1
c = 14.453 (3) Å	T = 293 K
β = 115.46 (3)°	Cube, colourless
V = 3043.5 (11) Å^3	0.24 × 0.21 × 0.17 mm
Z = 4

Data collection

Rigaku Mercury CCD area-detector diffractometer	3349 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.035
Graphite monochromator	θmax = 27.5°, θmin = 3.1°
ω scans	h = −34→33
12400 measured reflections	k = −11→11
3494 independent reflections	l = −13→18

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.068	H-atom parameters constrained
S = 1.23	w = 1/[σ^2(Fo^2) + (0.0113P)^2 + 5.5854P] where P = (Fo^2 + 2Fc^2)/3
3494 reflections	(Δ/σ)max < 0.001
205 parameters	Δρmax = 0.39 e Å^−3
0 restraints	Δρmin = −0.26 e Å^−3

Special details

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 >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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cd1	0.5000	0.5000	0.5000	0.02616 (8)
Cl1	0.41333 (3)	0.34130 (8)	0.38539 (5)	0.03487 (15)
S1	0.45032 (3)	0.63726 (8)	0.60981 (5)	0.02923 (14)
O1	0.25935 (8)	0.6262 (2)	0.44396 (17)	0.0468 (6)
N1	0.34748 (9)	0.5318 (2)	0.48917 (16)	0.0287 (5)
H1	0.3656	0.4642	0.4726	0.034*
N2	0.35198 (9)	0.7333 (2)	0.59269 (16)	0.0304 (5)
H10	0.3158	0.7314	0.5660	0.037*
N3	0.38086 (9)	0.8371 (2)	0.66833 (16)	0.0297 (5)
H3	0.3884	0.8183	0.7312	0.036*
N4	0.46686 (9)	1.3021 (2)	0.87810 (16)	0.0293 (5)
O2	0.38809 (11)	0.9997 (2)	0.55513 (15)	0.0547 (6)
C1	0.21305 (15)	0.1154 (4)	0.2926 (3)	0.0593 (10)
H4	0.1950	0.0264	0.2620	0.071*
C2	0.26365 (16)	0.1101 (4)	0.3779 (3)	0.0557 (9)
H2	0.2800	0.0176	0.4045	0.067*
C3	0.29043 (13)	0.2425 (3)	0.4247 (2)	0.0434 (7)
H9	0.3253	0.2391	0.4813	0.052*
C4	0.26513 (11)	0.3792 (3)	0.3869 (2)	0.0340 (6)
C5	0.21404 (12)	0.3845 (4)	0.3002 (2)	0.0452 (8)
H5	0.1968	0.4765	0.2746	0.054*
C6	0.18907 (13)	0.2514 (4)	0.2525 (3)	0.0578 (10)
H6	0.1557	0.2542	0.1926	0.069*
C7	0.28880 (11)	0.5233 (3)	0.4406 (2)	0.0321 (6)
C8	0.37951 (10)	0.6364 (3)	0.56055 (18)	0.0248 (5)
C9	0.39726 (11)	0.9688 (3)	0.6423 (2)	0.0318 (6)
C10	0.42468 (11)	1.0792 (3)	0.72875 (19)	0.0291 (5)
C11	0.44504 (14)	1.0437 (3)	0.8315 (2)	0.0458 (8)
H11	0.4448	0.9446	0.8523	0.055*
C12	0.46586 (14)	1.1585 (3)	0.9029 (2)	0.0441 (8)
H12	0.4799	1.1336	0.9720	0.053*
C13	0.42716 (12)	1.2273 (3)	0.7029 (2)	0.0324 (6)
H13	0.4151	1.2548	0.6346	0.039*
C14	0.44756 (12)	1.3344 (3)	0.7789 (2)	0.0326 (6)
H14	0.4479	1.4344	0.7601	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.02771 (13)	0.02192 (13)	0.02609 (13)	0.00408 (11)	0.00894 (10)	0.00354 (10)
Cl1	0.0310 (3)	0.0327 (3)	0.0398 (4)	−0.0015 (3)	0.0142 (3)	−0.0098 (3)
S1	0.0229 (3)	0.0317 (3)	0.0297 (3)	0.0009 (3)	0.0081 (3)	−0.0057 (3)
O1	0.0265 (10)	0.0482 (13)	0.0578 (13)	0.0032 (9)	0.0106 (10)	−0.0231 (11)
N1	0.0242 (10)	0.0261 (11)	0.0347 (11)	−0.0002 (9)	0.0116 (9)	−0.0113 (9)
N2	0.0247 (10)	0.0291 (11)	0.0342 (12)	−0.0027 (9)	0.0095 (9)	−0.0137 (9)
N3	0.0334 (12)	0.0262 (11)	0.0268 (11)	−0.0029 (9)	0.0102 (9)	−0.0093 (9)
N4	0.0326 (12)	0.0246 (11)	0.0260 (10)	−0.0043 (9)	0.0081 (9)	−0.0031 (9)
O2	0.0878 (18)	0.0362 (11)	0.0285 (10)	−0.0085 (12)	0.0141 (11)	−0.0026 (9)
C1	0.052 (2)	0.054 (2)	0.078 (3)	−0.0258 (18)	0.034 (2)	−0.039 (2)
C2	0.065 (2)	0.0378 (18)	0.067 (2)	−0.0123 (17)	0.031 (2)	−0.0146 (16)
C3	0.0446 (17)	0.0367 (16)	0.0457 (17)	−0.0073 (14)	0.0163 (14)	−0.0087 (13)
C4	0.0280 (13)	0.0381 (15)	0.0378 (15)	−0.0075 (12)	0.0160 (12)	−0.0143 (12)
C5	0.0296 (15)	0.0530 (19)	0.0510 (18)	−0.0025 (14)	0.0154 (14)	−0.0195 (15)
C6	0.0314 (16)	0.076 (3)	0.062 (2)	−0.0154 (17)	0.0158 (16)	−0.037 (2)
C7	0.0260 (12)	0.0359 (15)	0.0334 (13)	−0.0031 (11)	0.0119 (11)	−0.0105 (11)
C8	0.0267 (12)	0.0214 (12)	0.0246 (12)	0.0002 (10)	0.0096 (10)	−0.0002 (10)
C9	0.0346 (14)	0.0266 (14)	0.0279 (13)	0.0012 (11)	0.0075 (11)	−0.0051 (10)
C10	0.0287 (13)	0.0249 (13)	0.0285 (13)	−0.0016 (11)	0.0074 (11)	−0.0037 (10)
C11	0.066 (2)	0.0206 (13)	0.0322 (15)	−0.0040 (13)	0.0032 (14)	−0.0002 (11)
C12	0.065 (2)	0.0239 (14)	0.0274 (14)	−0.0070 (14)	0.0049 (14)	0.0012 (11)
C13	0.0403 (15)	0.0294 (14)	0.0264 (13)	−0.0058 (12)	0.0132 (12)	−0.0008 (11)
C14	0.0413 (15)	0.0235 (13)	0.0317 (13)	−0.0059 (11)	0.0143 (12)	−0.0006 (11)

Geometric parameters (Å, º)

Cd1—N4^i	2.373 (2)	C1—C2	1.371 (5)
Cd1—N4^ii	2.373 (2)	C1—H4	0.9300
Cd1—Cl1	2.5828 (10)	C2—C3	1.387 (4)
Cd1—Cl1^iii	2.5828 (10)	C2—H2	0.9300
Cd1—S1	2.7364 (8)	C3—C4	1.378 (4)
Cd1—S1^iii	2.7364 (8)	C3—H9	0.9300
S1—C8	1.682 (3)	C4—C5	1.388 (4)
O1—C7	1.211 (3)	C4—C7	1.487 (4)
N1—C8	1.374 (3)	C5—C6	1.384 (4)
N1—C7	1.395 (3)	C5—H5	0.9300
N1—H1	0.8600	C6—H6	0.9300
N2—C8	1.330 (3)	C9—C10	1.505 (3)
N2—N3	1.381 (3)	C10—C13	1.376 (4)
N2—H10	0.8600	C10—C11	1.381 (4)
N3—C9	1.354 (3)	C11—C12	1.385 (4)
N3—H3	0.8600	C11—H11	0.9300
N4—C12	1.327 (3)	C12—H12	0.9300
N4—C14	1.330 (3)	C13—C14	1.376 (4)
N4—Cd1^iv	2.373 (2)	C13—H13	0.9300
O2—C9	1.209 (3)	C14—H14	0.9300
C1—C6	1.370 (5)
N4^i—Cd1—N4^ii	180.00 (9)	C4—C3—H9	120.1
N4^i—Cd1—Cl1	90.76 (6)	C2—C3—H9	120.1
N4^ii—Cd1—Cl1	89.24 (6)	C3—C4—C5	120.1 (3)
N4^i—Cd1—Cl1^iii	89.24 (6)	C3—C4—C7	121.9 (3)
N4^ii—Cd1—Cl1^iii	90.76 (6)	C5—C4—C7	117.8 (3)
Cl1—Cd1—Cl1^iii	180.0	C6—C5—C4	119.2 (3)
N4^i—Cd1—S1	90.77 (6)	C6—C5—H5	120.4
N4^ii—Cd1—S1	89.23 (6)	C4—C5—H5	120.4
Cl1—Cd1—S1	96.09 (2)	C1—C6—C5	120.6 (3)
Cl1^iii—Cd1—S1	83.91 (2)	C1—C6—H6	119.7
N4^i—Cd1—S1^iii	89.23 (6)	C5—C6—H6	119.7
N4^ii—Cd1—S1^iii	90.77 (6)	O1—C7—N1	121.8 (2)
Cl1—Cd1—S1^iii	83.91 (2)	O1—C7—C4	122.6 (2)
Cl1^iii—Cd1—S1^iii	96.09 (3)	N1—C7—C4	115.6 (2)
S1—Cd1—S1^iii	180.000 (18)	N2—C8—N1	116.8 (2)
C8—S1—Cd1	117.96 (9)	N2—C8—S1	121.17 (19)
C8—N1—C7	127.0 (2)	N1—C8—S1	122.00 (19)
C8—N1—H1	116.5	O2—C9—N3	122.7 (2)
C7—N1—H1	116.5	O2—C9—C10	121.9 (2)
C8—N2—N3	120.8 (2)	N3—C9—C10	115.3 (2)
C8—N2—H10	119.6	C13—C10—C11	117.9 (2)
N3—N2—H10	119.6	C13—C10—C9	117.3 (2)
C9—N3—N2	119.3 (2)	C11—C10—C9	124.7 (2)
C9—N3—H3	120.4	C10—C11—C12	118.7 (3)
N2—N3—H3	120.4	C10—C11—H11	120.7
C12—N4—C14	117.1 (2)	C12—C11—H11	120.7
C12—N4—Cd1^iv	123.66 (18)	N4—C12—C11	123.6 (3)
C14—N4—Cd1^iv	119.24 (17)	N4—C12—H12	118.2
C6—C1—C2	120.2 (3)	C11—C12—H12	118.2
C6—C1—H4	119.9	C14—C13—C10	119.4 (2)
C2—C1—H4	119.9	C14—C13—H13	120.3
C1—C2—C3	120.1 (3)	C10—C13—H13	120.3
C1—C2—H2	119.9	N4—C14—C13	123.3 (2)
C3—C2—H2	119.9	N4—C14—H14	118.4
C4—C3—C2	119.7 (3)	C13—C14—H14	118.4

Symmetry codes: (i) −x+1, y−1, −z+3/2; (ii) x, −y+2, z−1/2; (iii) −x+1, −y+1, −z+1; (iv) −x+1, y+1, −z+3/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl1	0.86	2.39	3.214 (2)	161
N3—H3···Cl1^v	0.86	2.48	3.283 (3)	156
N2—H10···O1	0.86	1.98	2.637 (3)	132
N2—H10···O1^vi	0.86	2.30	3.010 (3)	141
C6—H6···Cg1^vi	0.93	2.74	3.327 (4)	122

Symmetry codes: (v) x, −y+1, z+1/2; (vi) −x+1/2, −y+3/2, −z+1.