Boron analogs of the 2-norbornyl cation

The relative stability of classical versus nonclassical mono- and bis-boron analogs of the 2-norbornyl cation was investigated by ab initio and density functional methods. Nonclassical structures were preferred in carbon bridged isoelectronic 1,2-diboranorbornyl anions having the following substituents on boron: H, CH3 and CN. The difluoro analog preferred the classical structure. The mono-boron analog preferred an open structure.