Synthesis and Crystal Structures of a Pair of Isostructural Azido-Bridged Polynuclear Schiff Base Zinc(II) Complexes

A pair of novel isostructural azido-bridged polynuclear zinc(II) complexes, [Zn-2(L1)(2)(mu(1,1)-N-3)(mu(1,3)-N-3)] (n) (1) and [Zn-2(L2)(2)(mu(1,1)-N-3)(mu(1,3)-N-3)] (n) (2) (HL1 = 2-bromo-4-chloro-6-[(2-isopropylaminoethylimino)methyl]phenol, HL2 = 2,4-dibromo-6-[(2-isopropylaminoethylimino)methyl]phenol), have been synthesized and structurally characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. Both complexes crystallize in the orthorhombic space group Pcca. Crystal data for (1): a = 22.567(4) , b = 8.414(2) , c = 17.268(3) , V = 3279.0(11) (3), Z = 8, R (1) = 0.0441, and wR (2) = 0.0846. Crystal data for (2): a = 22.536(4) , b = 8.409(2) , c = 17.531(3) , V = 3322.2(11) (3), Z = 8, R (1) = 0.0538, and wR (2) = 0.0906. X-ray structure determination revealed that each zinc(II) atom in the complexes is in a trigonal-bipyramidal coordination, with one imine N atom of a Schiff base ligand and two N atoms from two bridging azide ligands defining the basal plane, and one phenolate O and one amine N atoms of the Schiff base ligand occupying the two axial positions.