Synthesis, spectral characterization and crystal structures of benzyltin complexes with (E)-4-chloro-N′-(2-hydroxy-4-methoxybenzylidene)benzohydrazide

The reactions of the Schiff base ligand (E)-4-chloro-N'-(2-hydroxy-4-methoxybenzylidene)benzohydrazide (L) with substituted dibenzyltin dichlorides yielded a series of monobenzyltin complexes with the general formula (RC7H6)Sn(L)(S)Cl, where R = p-CH3, p-Cl, H, p-F, p-Br, o-CH3, o-F and S = H2O, methanol. An exception to this was obtained for the reaction with di(o-chlorobenzyl)tin dichloride, in which the di(o-chlorobenzyl)tin complex, (o-ClC7H6)(2)Sn(L) was the sole product. An attempt to displace the solvent molecule in the monobenzyltin complexes with 4,4,-bipyridine resulted in a mixture of products, containing a co-crystal of the methanol coordinated monobenzyltin complex and 4,4-bipyridine, (RC7H6)-Sn(L)(CH3OH)Cl center dot 4,4-bipyridine, and a six-coordinated dibenzyltin complex, (RC7H6)(2)Sn(L)Cl center dot CH3OH. If the donor ligand 4,4'-bipyridine or 4,4'-bipyridine N,N'-dioxide (L') was added in-situ during the preparation of the benzyltin complexes, either a dibenzyltin complex, (RC7H6)(2)Sn(L), or a binuclear dibenzyltin complex with the donor ligand (L'), (RC7H6)(2)SnCl2(L') [R = p-F], was obtained. Interestingly, both cis- and trans-(RC7H6)(2)SnCl2(L') complexes could be formed, as evidenced from their crystal structures. The structural formula of all the products were confirmed by elemental analysis, IR, H-1 and C-13 NMR spectroscopic studies and by X-ray analysis. (C) 2014 Elsevier Ltd. All rights reserved.