title: Metal-metal interactions in heterobimetallic d8-d10 complexes. Structures and spectroscopic investigation of [M'M' '(mu-dcpm)2(CN)2]+ (M' = Pt, Pd; M' ' = Cu, Ag, Au) and related complexes by UV-vis absorption and resonance Raman spectroscopy and ab initio calculations.
abstract: X-ray structural and spectroscopic properties of a series of heterodinuclear d(8)-d(10) metal complexes [M'M' '(mu-dcpm)(2)(CN)(2)](+) containing d(8) Pt(II), Pd(II), or Ni(II) and d(10) Au(I), Ag(I), or Cu(I) ions with a dcpm bridging ligand have been studied (dcpm = bis(dicyclohexylphosphino)methane; M' = Pt, M' ' = Au 4, Ag 5, Cu, 6; M' ' = Au, M' = Pd 7, Ni 8). X-ray crystal analyses showed that the metal...metal distances in these heteronuclear metal complexes are shorter than the sum of van der Waals radii of the M' and M' ' atoms. The UV-vis absorption spectra of 4-6 display red-shifted intense absorption bands from the absorption spectra of the mononuclear trans-[Pt(phosphine)(2)(CN)(2)] and [M' '(phosphine)(2)](+) counterparts, attributable to metal-metal interactions. The resonance Raman spectra confirmed assignments of (1)[nd(sigma)-->(n + 1)p(sigma)] electronic transitions to the absorption bands at 317 and 331 nm in 4 and 6, respectively. The results of theoretical calculations at the MP2 level reveal an attractive interaction energy curve for the skewed [trans-Pt(PH(3))(2)(CN)(2)-Au(PH(3))(2)(+)] dimer. The interaction energy of Pt(II)-Au(I) was calculated to be ca. 0.45 ev.
authors.affiliation: Department of Chemistry and the HKU-CAS Joint Laboratory on New Materials, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, P. R. China.
authors.forename: Bao-Hui
authors.initials: BH
authors.lastname: Xia
authors.forename: Hong-Xing
authors.initials: HX
authors.lastname: Zhang
authors.forename: Chi-Ming
authors.initials: CM
authors.lastname: Che
authors.forename: King-Hung
authors.initials: KH
authors.lastname: Leung
authors.forename: David Lee
authors.initials: DL
authors.lastname: Phillips
authors.forename: Nianyong
authors.initials: N
authors.lastname: Zhu
authors.forename: Zhong-Yuan
authors.initials: ZY
authors.lastname: Zhou