Molecular Cage Assembly by Sn-O-Sn Bridging of Di-, Tri- and Tetranuclear Organotin Tectons: Extending the Spacing in Double Ladder Structures.

Abstract

Hydrolysis reactions of di‐ and trinuclear organotin halides yielded large novel cage compounds containing Sn−O−Sn bridges. The molecular structures of two octanuclear tetraorganodistannoxanes showing double‐ladder motifs, viz., [{Me3SiCH2(Cl)SnCH2YCH2Sn(OH)CH2SiMe3}2(μ‐O)2]2 [1, Y=p‐(Me)2SiC6H4‐C6H4Si(Me)2] and [{Me3SiCH2(I)SnCH2YCH2Sn(OH)CH2SiMe3}2(μ‐O)2]2 ⋅0.48 I2 [2⋅0.48 I2, Y=p‐(Me)2SiC6H4‐C6H4Si(Me)2], and the hexanuclear cage‐compound 1,3,6‐C6H3(p‐C6H4Si(Me)2CH2Sn(R)2OSn(R)2CH2Si(Me)2C6H4‐p)3C6H3‐1,3,6 (3, R=CH2SiMe3) are reported. Of these, the co‐crystal 2⋅0.48 I2 exhibits the largest spacing of 16.7 Å reported to date for distannoxane‐based double ladders. DFT calculations for the hexanuclear cage and a related octanuclear congener accompany the experimental work.