Asymmetric Pentameric and Tetrameric Organooxotin Clusters: Insights into Their Formation through Partial Dearylation

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−, O2−, ROPO32−, 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.