The First Spacer-Bridged Tetraorganodistannoxanes with a Mixed Double Ladder Structure

摘要

The reaction of Me_3SiCH_2Cl_2Sn(CH_2)_3SnCl_2Ph (6) with (tBu_2SnO)_3 gave a statistical mixture of the corresponding tetraorganodistannoxanes whereas the reaction of the spacer-bridged ditin tetrachlorides RCl_2Sn(CH_2)_4SnCl_2R (3,R=Me_3CCH_2; 4, R=Me_2CHCH_2; 10, R=Me_3SiCH_2) with the polymeric spacer-bridged ditin oxides [R(O)Sn(CH_2)_4-Sn(O)R]_n (7, R=Me_2CHCH_2; 8, R=Me_3CCH_2; 11, R=Me_3SiCH_2) provided the mixed double ladder compounds {[R(Cl)Sn(CH_2)_4Sn(Cl)R][R'(Cl)Sn(CH_2)_4Sn(Cl)R']O_2}_2 (9, R=Me_3CCH_2, R'=Me_2CHCH_2; 12, R=Me_3CCH_2, R'=Me_3SiCH_2) in almost quantitative yield. In solution, 9 and 12 are in equilibrium with their corresponding dimers, as was evidenced by ~(119)Sn NMR spectroscopy, molecular mass determination, and electrospray mass spectrometry. The molecular structures of 9 and 12 were established by single crystal X-ray diffraction.