Synthesis and characterization of diorganotin(IV)complexes of tridentate Schiff bases:crystal structure of[N-(3-hydroxypyridine-2-yl)-5-chlorosalicylideneiminato]dimethyltin(IV)

摘要

Some five-coordinated dimethyltin(IV)complexes of the type Me2SnL(where L is the anion of a bifunctional tridentate Schiff base)were synthesized.These Schiff bases are N-(3-hydroxypyridine-2-yl)-3-methoxysal-icylideneimine,HOC6H3OCH3CH=NC5H3NOH(1),N-(3-hydroxypyridine-2-yl)-3-ethoxysalicylideneimine,HO-C6H3OC2H5CH=NC5H3NOH(2),N-(3-hydroxypyridine-2-yl)-5-chlorosalicylideneimine,HOC6H3ClCH=NC5H3 NOH(3),and N-(3-hydroxypyridine-2-yl)-3-methoxy-5-bromosahcylideneimine,HOC6H2OCH3BrCH=NC5H3 NOH(4).Dimethyltin(IV)complex of 3(3a)was characterized by single crystal X-ray diffraction method and a coordination geometry that is nearly halfway between tri-gonal-bipyramidal and square pyramidal arrangement was found.Dimethyltin complexes of(1),(2),and(4)were also prepared and characterized by the comparison of their elemental analysis and 1H-NMR-,IR-,UV-and mass spectral data with those of(3a).For example,in the 1H-NMR spectra,the 2J(119Sn-1H)in the Sn-CH3 moiety have values between 80 Hz and 90 Hz,typical of five-coordinated tin species.By using these values in Lockart's Equations,H3C-Sn-CH3 angles in the complexes were estimated to lie between 130° and 145°.X-ray diffraction value for 3a,confirms this estimate within 3.4% relative deviation(129.7° exp.Vs.134.9° estimate).