Ring-whizzing in polyene-PtL2 complexes revisited

Ring-whizzing was investigated by hybrid DFT methods in a number of polyene-Pt(diphosphinylethane) complexes. The polyenes included cyclopropenium+ , cyclobutadiene, cyclopentadienyl+ , hexafluorobenzene, cycloheptatrienyl+ , cyclooctatetraene, octafluorooctatetraene, 6-radialene, pentalene, phenalenium+ , naphthalene and octafluoronaphthalene. The HOMO of a d10 ML2 group (with b2 symmetry) interacting with the LUMO of the polyene was used as a model to explain the occurrence of minima and maxima on the potential energy surface.