Synthesis, spectroscopy and structure of [N-(2-carboxyphenyl)salicylideneiminato]dimethyltin(IV)

The novel dimethyltin complex with formula Me2Sn(2-OC6H4CH=NC6H4COO), compo und 1, involving the Schiff base derived from anthranilic acid and salicyla ldehyde, has been synthesized and characterized by elemental analysis, IR,H -1-,C-13- and Sn-117-NMR, Sn-119 Mossbauer spectroscopy and single-crystal X-ray diffraction structure analysis. The crystals of complex 1 are monocli nic, space group P2(1)/n, a = 8.907(5), b = 12.044(7), c = 14.062(9) Angstr om, beta = 104.99(5)degrees, Z = 4, R-1 = 0.0296, R-w(2) = 0 08 for 1368 ob served reflections. The crystal structure of 1 features centrosymmetric dim ers disposed about a central Sn,Ol core. The tin environment is seven-coord inate if a moderately long contact distance Sn(1)-O(2a) (2.69(1) Angstrom) and a longer one Sn(1)-O(3a) (3.03(1) Angstrom) are included in the coordin ation list. In the basic monomeric structural unit, the tin configuration c an be seen as a distorted square-pyramid with the imine nitrogen atom in ap ical position, the N-(2-carboxyphenyl)salicylideneimine dianion coordinatin g a single tin atom via the phenolate oxygen atom, the imine nitrogen atom and one of the carboxylate oxygen atoms. The distortion of the square pyram id is discussed in terms of a trend to trigonal-bipyramidal geometry. (C) 1 999 Elsevier Science S.A. All rights reserved.