catena-Poly[[di-μ-chlorido-bis­{[6-methoxy-2-(4-methyl­phenyl­iminio­methyl)phenolato-κ2 O,O′]cadmium(II)}]-di-μ2-thio­cyanato-κ2 N:S;κ2 S:N]

Hua-Qiong Li; Hui-Duo Xian; Jian-Feng Liu; Guo-Liang Zhao

doi:10.1107/S1600536808038099

. 2008 Nov 22;64(Pt 12):m1593–m1594. doi: 10.1107/S1600536808038099

catena-Poly[[di-μ-chlorido-bis{[6-methoxy-2-(4-methylphenyliminiomethyl)phenolato-κ² O,O′]cadmium(II)}]-di-μ₂-thiocyanato-κ² N:S;κ² S:N]

Hua-Qiong Li ^a, Hui-Duo Xian ^a, Jian-Feng Liu ^a, Guo-Liang Zhao ^a,^*

PMCID: PMC2959993 PMID: 21581192

Abstract

The asymmetric unit of the title compound, [Cd₂Cl₂(NCS)₂(C₁₅H₁₅NO₂)₂]_n, contains the Schiff base 2-[(4-methylphenylimino)methyl]-6-methoxyphenol (HL) ligand, one thiocyanate and one chloride ligand coordinated to a cadmium centre. The cadmium centers are linked to each other via two thiocyanate and two chloride bridges alternately, resulting in centrosymmetric zigzag chains running parallel to the a axis. The Cd^II coordination environment contains two Cl atoms, one thiocyanate (SCN) S atom, one isothiocyanate (NCS) N atom and two O atoms from the HL ligand. The Schiff base ligand is in the trans conformation.

Related literature

For related literature regarding Schiff bases and their complexes, see: Mondal et al. (1999 ▶); Sen et al. (2006 ▶); Yi et al. (2004 ▶); Yu et al. (2007 ▶); Zhao et al. (2007 ▶); Zhou & Zhao (2007 ▶). For related structures, see: Ding et al. (2006 ▶); Suh et al. (2007 ▶).

Experimental

Crystal data

[Cd₂Cl₂(NCS)₂(C₁₅H₁₅NO₂)₂]
M _r = 447.23
Triclinic,
a = 9.0485 (2) Å
b = 9.7321 (2) Å
c = 10.6676 (3) Å
α = 71.518 (2)°
β = 77.444 (2)°
γ = 80.732 (2)°
V = 865.32 (4) Å³
Z = 2
Mo Kα radiation
μ = 1.55 mm⁻¹
T = 296 (2) K
0.27 × 0.11 × 0.08 mm

Data collection

Bruker APEXII diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.82, T _max = 0.882
13032 measured reflections
3940 independent reflections
3225 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.081
S = 1.01
3940 reflections
208 parameters
H-atom parameters constrained
Δρ_max = 0.54 e Å⁻³
Δρ_min = −0.52 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: SAINT (Bruker, 2006 ▶); 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: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808038099/ez2146sup1.cif

e-64-m1593-sup1.cif^{(21KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808038099/ez2146Isup2.hkl

e-64-m1593-Isup2.hkl^{(190KB, hkl)}

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

supplementary crystallographic information

Comment

salen-type Schiff bases are capable of forming complexes with different coordination modes, with certain metal ions. Some of these compounds have promising applications in catalysis, enzyme models and optical and magnetic materials (Sen et al., 2006). In addition, the unusual coordination modes of Schiff base ligands leads to unusual structures of the complexes. In previous articles (Zhou & Zhao, 2007; Yu et al., 2007; Zhao et al., 2007), we reported the synthesis and the ligating properties of the title Schiff base ligand, HL, derived from the condensation of o-vanillin and p-toluidine, to several transition and rare earth metals with different anions. In addition, many coordination polymers of one-, two-, and three-dimensional infinite frameworks involving cadmium(II) ions have been synthesized and studied due to their potential applications (Mondal et al., 1999). Coordination polymers of cadmium(II) have been exploited using anionic ligands, e.g., Cl^-, Br^-, I^-, SCN^-, N3^-, SeCN^-, etc., which are also an essential part of the coordination polyhedron, besides the organic ligand (Yi et al., 2004). Here we decribe the synthesis and crystal structure of a new cadmium(II) complex (Figure 1), [Cd(HL)(SCN)Cl]_n, involving the Schiff base HL.

As shown in Fig. 1 and 2, each Cd^II atom is hexacoordinated by two Cl atoms, one thiocyanate S atom, one isothiocyanate N atom and two O atoms from the Schiff base ligand, HL. The HL ligand is in the trans conformation. The geometry around the Cd^II atom is a distorted octahedron. Neighbouring octahedral Cd centres are bridged by, alternately, the SCN and NCS ligands and two Cl ligands to form alternating eight-membered Cd—S—C—N—Cd—S—C—N– and four-membered Cd—Cl—Cd—Cl- rings. These chains run parallel to the a axis. The Cd—S_SCN bond length is longer than the Cd—N_NCS distance [2.7096 (11) versus 2.2484 (26) Å], which, together with the bond angles, are similar to related compounds in the literatures (Suh et al., 2007; Ding et al., 2006).

Experimental

First, the ligand was prepared by the direct solid-phase reaction of o-vanillin (10 mmol, 1.5251 g) and p-toluidine (10 mmol, 1.0700 g). The reactants were ground in an agate mortar. The color of the mixture changed from light yellow to orange. Then, for the preparation of the complex, a solution of CdCl₂. 2.5H₂O (1 mmol, 0.2931 g) and KSCN (0.1945 g, 2 mmol) in methanol (10 ml) was added to a methanol (30 ml) solution of the Schiff base ligand (2 mmol, 0.4826 g). Yellow crystals were obtained after 10 days.