The first spacer-bridged tetraorganodistannoxanes with a mixed double ladder structure

Article abstract of DOI:10.1002/1099-0682(20011)2001:1<153::aid-ejic153>3.0.co;2-m

The reaction of Me₃SiCH₂Cl₂ Sn(CH₂)₃SnCl₂Ph (6) with (tBu₂SnO)₃ gave a statistical mixture of the corresponding tetraorganodistannoxanes whereas the reaction of the spacer-bridged ditin tetrachlorides RCl₂Sn(CH₂)₄SnCl₂R (3, R = Me₃CCH₂; 4, R = Me₂CHCH₂; 10, R = Me₃SiCH₂) with the polymeric spacer-bridged ditin oxides [R(O)Sn(CH₂)₄-Sn(O)R]_n (7, R = Me₂CHCH₂; 8, R = Me₃CCH₂; 11, R = Me₃SiCH₂) provided the mixed double ladder compounds {[R(Cl)Sn(CH₂)₄ Sn(Cl)R][R′(Cl)Sn(CH₂)₄Sn(Cl)R′] O₂}₂ (9, R = Me₃CCH₂, R′ = Me₂CHCH₂; 12, R = Me₃CCH₂, R′ = Me₃SiCH₂) in almost quantitative yield. In solution, 9 and 12 are in equilibrium with their corresponding dimers, as was evidenced by ¹¹⁹Sn NMR spectroscopy, molecular mass determination, and electrospray mass spectrometry. The molecular structures of 9 and 12 were established by single crystal X-ray diffraction.