Synthesis And Characterization of Platinum(Ii)(2-(9-Anthracenylylidene)-4,5-Bis(Diphenylphosphino)-4-Cyclopenten-1,3-Dione)(Dichloride), Platinum(Ii)(2-(9-Anthracenylylidene)-4,5-Bis(Diphenylphosphino)-4-Cyclopenten-1,3-Dione(Maleonitriledithiolate), And Platinum(Ii)(4,5-Bis(Diphenylphosphino)-4-Cyclopenten-1,3-Dione)(4-Methyl-1,2-Benzene Dithiol)