Sterically hindered metal alkenyls. Part 2. Synthesis and properties of tin(IV) alkenyls: stereochemical features and energetics of isomerisation of SnMe2[C(C10H7)CMe2]2

Abstract

The compounds SnMe_4–nR¹_n[n= 1 or 2; R¹= C(C₁₀H₁₅)CH₂(C₁₀H₁₅= adamant-1-yl)], SnMe₂R²₂[R²= C(C₁₀H₇)CMe₂(C₁₀H₇= naphth-1-yl)], and SnBrR¹₃ have been prepared and characterised by elemental analysis, i.r. and n.m.r. spectroscopy, and mass spectrometry. The compound SnMe₂R²₂ exists as an unusual mixture of rotamers, which can be separated by crystallisation. The thermal conversion of one isomer into the other has been studied by variable-temperature n.m.r., and the energetics of Isomerisation determined.