摘要:
                                The nickel-promoted isomerization of a 3-vinylcyclobutene to the corresponding 1,4-cyclohexadiene was studied by using (PPh3)2Ni(C2H4) as the nickel source.  Through the use of chemical and electrochemical experiments, it was determined that nickel(I) and not nickel(0) promotes this isomerization reaction at room temperature.  The corresponding platinum-vinylcyclobutene complex 4 has been characterized by a single-crystal X-ray diffraction study:  C46H42O4P2Pt, monoclinic, P2(1)/n, with a = 10.774 (1) angstrom, b = 20.281 (4) angstrom, c = 18.297 (2) angstrom, beta = 97.37 (1)-degrees, Z = 4, R(F) = 0.0378, and R(w)(F) = 0.0371.