Synthesis and Structural Studies on Tetranuclear Tin Compositions Containing Tin {[R2Sn(LH)]2O}2 Moieties (R = Bu or Oct and LH = 4‐[((E)‐1‐{2‐Hydroxy‐5‐[(E)‐2‐(aryl)‐1‐diazenyl]phenyl}methylidene)‐ amino]benzoate)

Abstract

AbstractDiorganotin compounds containing tetranuclear tin compositions of the type {[R2Sn(LH)]2O}2 in which LH is deprotonated carboxylic acid LHH′ (H′ are the carboxylic and H the phenolic protons of the benzoic acid) HO2C–C6H4‐4‐{N=C(H)C6H3‐2‐OH‐5‐(N=N–C6H4X)} (X = H for L1H, X = 2‐CH3 for L2H, X = 3‐CH3 for L3H, and X = 4‐CH3 for L4H; R = Bu or Oct), were synthesized and characterized by FT‐IR, NMR, and 119Sn Mössbauer spectroscopy. One of the complexes, {[Oct2Sn(O2CC6H4{N=C(H)C6H3‐2‐OH‐5‐(N=NC6H4CH3‐2)})]2O}2 was characterized by single‐crystal X‐ray diffaraction, which revealed that the compound is a centrosymmetric tetranuclear bis(dicarboxylatotetrabutyldistannoxane) complex with a planar Sn4O2 core. The two μ3‐oxo oyxgen atoms are connected to a Sn2O2 ring and to two exocyclic tin atoms. The four carboxylate ligands display two different modes of coordination. Both modes of coordination involve bridging two structurally distinct tin atoms. The solution structures of the complexes were unravelled by 119Sn NMR spectroscopy, and found to be identical to those of the crystalline state.