Diorganotin(IV) complexes of polyaromatic azo‐azomethine ligand derived from salicylaldehyde and <i>ortho</i>‐aminophenol: Synthesis, characterization, and molecular structures

Abstract

Abstract The diorganotin(IV) complexes of methyl 2‐{4‐hydroxy‐3‐[(2‐hydroxy‐phenylimino)‐methyl]‐phenylazo}‐benzoate (H2L) were obtained by the reaction of ortho ‐aminophenol, R 2 SnO (R = Me, n Bu, or Ph) and methyl 2‐[(E)‐(3‐formyl‐4‐hydroxy)diazenyl]benzoate (H2PL 2 ) in ethanol, which led to diorganotin(IV) compounds of composition [Me 2 SnL] 2 ( 1 ), n Bu 2 SnL ( 2 ), and Ph 2 SnL ( 3 ) in good yield. The 1 H, 13 C, and 119 Sn NMR, IR, the mass spectrometry along with elemental analyses allowed establishing the structure of ligand (H2L) and compounds 1–3 . In all the three cases, 119 Sn chemical shifts are indicators of five‐coordinated Sn atoms in a solution state. The crystal structures of ligand H2L and complexes 1 and 2 were determined by a single crystal X‐ray diffraction study. In the solid state, the ligand H2L exists as a keto‐enamine tautomeric form. The molecular structure of complex 1 in the solid state shows a distorted octahedral geometry around a tin atom due to additional coordination with an oxygen atom from a neighboring molecule leading to a four‐membered ring with Sn‐O···Sn‐O intermolecular coordination, leading to a dimeric species. On the other hand, complex 2 is a monomer with trigonal bipyramidal geometry surrounding the tin atom. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:457–465, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21037