Sterically-induced low temperature polyhedral rearrangements of carbaplatinaboranes: synthesis and crystal structures of 1-Ph-3,3-(PMe2Ph)2-3,1,2-PtC2B9H10, 1-Ph-3,3-(PMe2Ph)2-3,1,11-PtC2B9H10, 11-Ph-3,3-(PMe2Ph)2-3,1,11-PtC2B9H10 and 1,11-Ph2-3,3-(PMe2Ph)2-3,1,11-PtC2B9H9

Article abstract of DOI:10.1016/0022-328X(93)80258-D

Reaction of cis-Pt(PMe2Ph)2Cl2 with Tl2<7-Ph-7,8-nido-C2B9H10> affords 1-Ph-3,3-(PMe2Ph)2-3,1,2-PtC2B9H10, mild thermolysis (55 deg C) of which yields 1-Ph-3,3-(PMe2Ph)2-3,1,11-PtC2B9H10 and 11-Ph-3,3-(PMe2Ph)2-3,1,11-PtC2B9H10.Both of the latter compounds are produced by the microwave irradiation of a mixture of cis-Pt(PMe2Ph)2Cl2 and <7-Ph-7,8-nido-C2B9H11>.When cis-Pt(PMe2Ph)2Cl2 is allowed to react with Tl2<7,8-Ph2-7,8-nido-C2B9H9> at room temperature the only isolable species is 1,11-Ph2-3,3-(PMe2Ph)2-3,1,11-PtC2B9H9.The generation of rearranged products with 3,1,11-PtC2B9 architectures is inconsistent with a diamond-square-diamond mechanism for the isomerisation of icosahedral heteroboranes.