Synthesis of a tetranuclear organooxotin cage by debenzylation reactions:: X-ray crystal structure of [(PhCH2)2Sn2O(O2P(OH)-t-Bu)4]2

The reactions of (PhCH2)(2)SnCl2, (PhCH2)(2)SnO.H2O, and (PhCH2)(3)SnCl with 2 equiv of t-BuP(O)(OH)(2) afford the tetranuclear organooxotin cage [(PhCH2)(2)Sn2O(O2P(OH)-t-Bu)(4)](2) (4) in good yields. The formation of the half-cage intermediate [(PhCH2)(2)Sn2O(O2P(OH)-t-Bu)(4)] (4a) en route to 4 has been detected by Sn-119 and P-31 NMR. The molecular structure of compound 4 as determined by single-crystal X-ray analysis shows a tetranuclear cage structure containing two Sn-O-Sn motifs connected by bridging [t-BuP(OH)(O)(2)](-) ligands. The solid-state structure of 4 is retained in solution.