title: Pyrazolato-bridged polynuclear palladium and platinum complexes. Synthesis, structure, and reactivity.
abstract: Cyclic trinuclear complexes [Pd(3)(mu-pz)(6)] (1) and [Pd(3)(mu-4-Mepz)(6)] (2) and dinuclear complex [Pd(2)(mu-3-t-Bupz)(2)(3-t-Bupz)(2)(3-t-BupzH)(2)] (3) have been prepared by the reactions of [PdCl(2)(CH(3)CN)(2)] with pyrazole (pzH), 4-methylpyrazole (4-MepzH), and 3-tert-butylpyrazole (3-t-BupzH), respectively, in CH(3)CN in the presence of Et(3)N. In the absence of the base, treatment of [PdCl(2)(CH(3)CN)(2)] with pzH gave the mononuclear complex, [Pd(pzH)(4)]Cl(2) (6). The reaction of [PtCl(2)(C(2)H(5)CN)(2)] with pzH in the presence of Et(3)N under refluxing in C(2)H(5)CN afforded the known dimeric Pt(II) complex, [Pt(pz)(2)(pzH)(2)](2) (7). The protons participating in the hydrogen bonding in 3 and 7 are easily replaced by silver ions to give the heterotetranuclear complex [Pd(2)Ag(2)(mu-3-t-Bupz)(6)] (4) and the heterohexanuclear complex [Pt(2)Ag(4)(mu-pz)(8)] (5). The complexes 1-6 are structurally characterized.
authors.affiliation: Department of Applied Chemistry, Faculty of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki 852-8521, Japan. kumks@net.nagasaki-u.ac.jp
authors.forename: Keisuke
authors.initials: K
authors.lastname: Umakoshi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yamauchi
authors.forename: Keiko
authors.initials: K
authors.lastname: Nakamiya
authors.forename: Takashi
authors.initials: T
authors.lastname: Kojima
authors.forename: Mikio
authors.initials: M
authors.lastname: Yamasaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kawano
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Onishi