Synthesis of platinum complexes with η4-C5Me4(CF3)H ligand. X-ray structure of [Pt(η4-C5Me4H2)Cl2] and [Pt{η4-C5Me4(CF3)H}(η5-C5H5)]PF6

Reaction of isomeric mixture of 1,2,3,4-tetramethyl-5-(trifluoromethyl)cyclopentadiene with Zeiseʹs salt dimer gave the only isomer [Pt{η4-C5Me4(CF3)H}Cl2] (1) bearing CF3 group exo to sp3 carbon atom in a high yield. An attempt to prepare 1 by reaction of K2PtCl4 with C5Me4(CF3)H using hydrochloric solution of tin dichloride as a catalyst unexpectedly resulted in a formation of [Pt(η4-C5Me4H2)Cl2] (2). The X-ray structure of compound 2 is presented. Reactions of 1 with AgBF4 in the presence of three different cyclopentadienes C5R14(R2)H (R1=R2=H; R1=R2=Me; R1=Me, R2=CF3) were studied. Crystal structure of complex [Pt{η4-C5Me4(CF3)H}(η5-C5H5)]PF6 (3) resulted from the reaction with cyclopentadiene was determined. When C5Me4(CF3)H is used the reaction yields [Pt{η4-C5Me4(CF3)H}{η5-C5Me4(CF3)}]BF4 (4) unstable in solutions. Reaction with pentamethylcyclopentadiene led to complex [Pt(η4-C5Me5H)(η5-C5Me5)]BF4 (5) and no complexes with CF3 containing ligands were obtained.