Synthesis and crystal structure of a tetranuclear carboxylate-bridged lanthanum(III)-zinc(II) complex [La2Zn2(m-CNC6H4COO)10(Py)2(C2H5OH)2]

The title complex was prepared from self-assembly reaction of La(NO3)(3). 6H(2)O, Zn(NO3)(2). 6H(2)O, m-cyanobenzoic acid (m-CNC6H4COOH) and pyridine (Py) in refluxing ethanol and its structure was determined by single-crystal X-ray diffraction. Crystallographic data: C94H62N12La2O22Zn2, M-r = 2120.12, triclinic space group P (1) over bar, a = 13.2219(5), b = 13.2713(5), c = 14.1987(6) Angstrom, alpha = 69.156(1), beta = 84.034(1), gamma = 89.400(1)degrees, V = 2314.9(2) Angstrom (3), Z = 1, D-c = 1.521 g/cm(3), F(000) = 1060, mu (MoK alpha) = 14.94 cm(-1), the final R= 0.043 and wR = 0.117 for 6381 unique reflections with I >2 sigma (I). Crystal structure determination shows that the neighboring lanthanum(III) and zinc(II) ions are bridged by three bidentate m-cyanobenzonate ligands in the syn-syn fashion to form a pair of dinuclear [LaZn(m-CNC6H4COO)(3)(PY)(C2H5OH)] subunits, being linked together by two bidentate and two tridentate m-cyanobenzonate groups in the syn-syn, and syn-anti modes, respectively, to construct a tetranuclear La-Zn complex [La2Zn2(m-CNC6H4COO)(10)(PY)(2)(C2H5OH)(2)].