Pyrazolato-Bridged Binuclear Complexes of Platinum(ii) with Carbonyl Ligands
by Johnson, Dale A.; Cordes, A. Wallace; Fithen-Kelley, Beverly A.
The majority of complexes containing bridging pyrazolato ligands [pz = C3H3N21-] have been shown to involve two or three bridging pz groups and to exhibit puckered MN4M' central rings; however, several recent examples of homo and heterobinuclear complexes with single bridging ligands and essentially planar central rings have been reported. The synthesis and structural characterization of a new member of this series trans-[(CO)ClPt(mu-pz)(mu-Cl)PtCl(CO)] and its mononuclear precursor trans-[Pt(CO)(Cl)2(Hpz)] are reported here. The mononuclear complex trans-[PtCl2(CO)(pzH)] crystallized in P2(1) with a = 3.417(1), b = 16.454(5), c = 14.571(3) angstrom, beta = 90.60(2)-degrees, V = 819.2(7) A3, and Z = 4. The overall complex is planar and stacked with the plantinum centers aligned in the a direction. The intermolecular Pt-Pt distance of 3.417(0) angstrom indicates a weak bonding interaction (van der Waals contact = 3.6 angstrom). The complex trans-(CO)ClPt(mu-Cl)(mu-pz)PtCl(CO) crystallized in P2(1)/c with a = 6.781(6), b = 17.750(4), c = 9.869(7) angstrom, beta = 106.07(6)-degrees, V = 1141(2) angstrom3, and Z = 4. The complex is planar to within 0.1(8) angstrom The molecules stack with nearly linear Pt-Pt chains t-Pt-Pt angle = 166.8-degrees). The shortest Pt-Pt intermolecular interactions are 3.399(5) and 3.427(5) angstrom.
- Journal of Coordination Chemistry
- Start Page
- 1029-0389; 0095-8972