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)2Sn(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·4,4-bipyridine, and a six-coordinated dibenzyltin complex, (RC7H6)2Sn(L)Cl·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)2Sn(L), or a binuclear dibenzyltin complex with the donor ligand (L′), (RC7H6)2SnCl2(L′) [R = p-F], was obtained. Interestingly, both cis- and trans-(RC7H6)2SnCl2(L′) complexes could be formed, as evidenced from their crystal structures. The structural formula of all the products were confirmed by elemental analysis, IR, 1H and 13C NMR spectroscopic studies and by X-ray analysis.

The reactions of the Schiff base ligand (E)-4-chloro-N′-(2-hydroxy-4-methoxybenzylidene)benzohydrazide with substituted dibenzyltin dichlorides afforded either monobenzyltin or dibenzyltin complexes, depending on the reaction conditions and the benzyl substituents. The subsequent reaction of a monobenzyltin complex with 4,4-bipyridine yielded a co-crystal containing the methanol coordinated monobenzyltin complex and 4,4-bipyridine.Figure optionsDownload as PowerPoint slide