Synthesis and characterization of cationic heteronuclear complexes of platinum(II) and silver(I) bridged by alkynyl ligands

Article abstract of DOI:10.1016/0022-328X(95)05832-A

The dialkynyl complexes cis-[Pt(C ≡ CR)₂L₂] [R = Ph, L₂ = 2PPh₃, 2PEt₃, dppe (dppe = 1,2-bis(diphenylphosphino)ethane]; R =^tBu, L₂ = 2PPh₃, dppe) react with silver perchlorate in a molar ratio 1:0.5 to give platinum-silver perchlorate salts of the type [Pt₂Ag(C ≡ CR)₄L₄]ClO₄) in excellent yield. The X-ray crystal structure of [Pt₂Ag(C ≡ CPh)₄(PPh₃)₄](ClO₄) 1 shows that the cation is formed by two nearly orthogonal cis-[Pt(C ≡ CPh)₂(PPh₃)₂] units connected through a silver cation which is unsymmetrically π-bonded to all four acetylene fragments. Similar reactions of cis-[Pt(C ≡ CR)₂L₂] with one equivalent of AgClO₄ afford cationic complexes of general formula [PtAg(C ≡ CR)₂L₂](ClO₄), which are believed to be salts, [Pt₂Ag₂(C ≡ CR)₄L₄](ClO₄)₂.