Asymmetric pentameric and tetrameric organooxotin clusters: insights into their formation through partial dearylation

Abstract

The reaction between diphenyltin dichloride and 2,6-diisopropylphenylphosphate (dippH₂) in ethanol affords a highly asymmetric pentameric organotin cluster, [Sn₅Ph₇(μ₃-dipp)₄(μ-dippH)(μ₃-O)(μ-OEt)(EtOH)(H₂O)Cl]·H₂O (1), that contains Ph^-, EtO^-, Cl^-, O^2-, ROPO₃^2-, ROPO₃H^-, OH₂, and EtOH ligands. The same reaction when carried out in iPrOH, under otherwise identical conditions, results in the formation of another pentamer, [Sn₅Ph₇(μ₃-dipp)₄(μ-dippH)(μ₃-O)(μ-OH)(iPrOH)(H₂O)Cl]·iPrOH (2). Change of the phosphate ligand to sterically less bulky 2,6-dimethylphenylphosphate in the above reaction carried out in ethanol results in the formation of a tetrameric cluster, [Sn₄Ph₅(μ₃-dmpp)₂(μ-dmpp)(μ-dmppH)₂(μ₃-O)(μ-OEt)(EtOH)]·EtOH (3). Isolation of 3 provides useful insights into the formation of the pentamers 1 and 2. Compounds 1-3 have been characterized by means of their analytical data, IR, and multinuclear NMR (¹H, ³¹P, and ¹¹⁹Sn) spectral data. The solid-state structures of 1-3 have been determined by X-ray diffraction studies.