The title compound, [Sn-4(CH3)(4)(C3H7)(4)Cl4O2] or {Cl[(CH3)(2)-CH](2)SnOS
n(CH3)(2)Cl}(2), obtained by the reaction of [(CH3)2 CH]2 SnO and (CH3)(2)S
nCl2, exists as centrosymmetric dimers in the solid state. It contains a ce
ntral planar four-membered Sn2O2 ring. The coordinate geometry about the Sn
atoms is distorted trigonal pyramidal.