Chlorine photoelimination from a diplatinum core: circumventing the back reaction.

The d(9)...d(9) Pt(2)(I,I)(tfepma)(2)Cl(2) (1) compound (tfepma = ((CF(3)CH(2)O)(2)P)(2)NCH(3)), d(7)-d(9) Pt(2)(I,III)(tfepma)(2)Cl(4) (2) and d(7)-d(7) Pt(2)(III,III)(tfepma)(2)Cl(6) (3), homologous suite of compounds have been prepared. Irradiation of 3 with visible light generates 2 in solution in the presence of 2,3-dimethyl-1,3-butadiene with a quantum efficiency of approximately 38%. The evolution of Cl(2) upon solid-state photolysis of 3 represents the first example of the thermodynamically unfavorable halogen elimination without the use of a chemical trap.