Synthesis of novel platinum-silver and platinum-copper complexes with bridging alkynyl ligands

Article abstract of DOI:10.1016/0022-328X(95)05215-B

The study of the reactivity of CR)8> M = Ag or Cu; R = Ph or ^tBu) towards different neutral and anionic ligands is reported.This study reveals that reactions of the phenylacetylide derivatives CPh)8> with anionic, X^- (X = Cl or Br) or neutral donors (CN^tBu or py) in a molar ratio 1:4 (M/donor ratio 1:1) yield the trinuclear anionic (NBu4)2<CPh)4>(MX)2> (M = Ag or Cu, X = Cl or Br) or neutral <CPh)4>(AgL)2> (L = CN^tBu or py) complexes, respectively.The crystal structure of (NBu4)2<CPh)4>(CuBr)2>(4) shows that the anion is formed by a dianionic Pt(C<*>CPh)4 fragment and two neutral CuBr units joined through bridging alkynyl ligands.All the alkynyl groups are ? bonded to Pt and η²-coordinated to a Cu atom which have an approximately trigonal-planar geometry.By contrast, similar reactions with C^tBu)8> (molar ratio M/donor 1:1) afford hexanuclear dianionic (NBu4)2C^tBu)8X2> or neutral C^tBu)8Py2>.Only by treatment with a large excess of Br^- (molar ratio M/Br^- 1:2) are the trinuclear complexes (NBu4)2<C^tBu)4>(MBr)2> (M = Ag, Cu) obtained.Attempted preparations of analogous complexes with phosphines (L' = PPh3 or PEt3) by reactions of CR)8> with L' leads to displacement of alkynyl ligands from platinum and formation of neutral mononuclear complexes CR)2L'2>. Keywords: Platinum; Silver; Alkynyl; Copper; Polynuclear; X-ray diffraction