Heterotrimetallic Complexes [{Pt(RNH2)2(μ-NHCOtBu)2}2M](ClO4)n (M = Mn, Co, Cu, Ni, Cd, and Zn, n = 2; M = In, n = 3), [{Pt(NH3)(μ-DACHCOtBu)(μ-NHCOtBu)}2Ni](ClO4)2, and [{Pt(RNH2)2(NHCOtBu)2}3Ag3](ClO4)3 Bridged by Amidate Ligands: A Novel Amidate−Amine Interligand Reaction During the Pt−Ni Bond Formation

✍ Scribed by Wanzhi Chen; Fenghui Liu; Takuya Nishioka; Kazulo Matsumoto

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 315 KB
• Volume: 2003
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200200684

✦ Synopsis

Abstract

The neutral square‐planar complexes [Pt(NH~2~CH~2~CH~2~OCH~3~)~2~(NHCO__t__Bu)~2~], [Pt(DACH)(NHCO__t__Bu)~2~] (DACH = trans‐1,2‐diaminocyclohexane), and [Pt(NH~2~CH~2~CH~2~NMe~2~)(NHCO__t__Bu)~2~] have been prepared by hydrolysis of the corresponding Pt(RNH~2~)~2~(NC__t__Bu)~2~~2~ with NaOH. Reactions of [Pt(RNH~2~)~2~(NHCO__t__Bu)~2~] with metal ions afforded Pt−M−Pt clusters {Pt(RNH~2~)~2~(μ‐NHCO__t__Bu)~2~}~2~M~n~ (M = Mn, Co, Cu, Ni, Cd, Zn, and In; n = 2 or 3) and {Pt(NH~2~CH~2~CH~2~NMe~2~)(μ‐NHCO__t__Bu)~2~}~2~M~2~ (M = Co, Ni). The Pt~2~M (M = Mn, Co, Cu, Ni, Zn, and In) complexes consist of a linear Pt−M−Pt core bridged by four pivalamidate ligands. The Pt−M−Pt angles are 180° or nearly so. The central metal ions with an octahedral geometry are coordinated by four equatorial amidate oxygen atoms and two platinum atoms occupy the axial site. One of the two t‐BuCO group shifts to the neighboring nitrogen atom of DACH (DACH = trans‐1,2‐diaminocyclohexane) in the reaction of [Pt(DACH)(NHCO__t__Bu)~2~]·4H~2~O with Ni^2+^ to generate the unexpected {Pt(NH~3~)(DACHCO__t__Bu)(μ‐NHCO__t__Bu)}~2~Ni~2~. The central Cd ion in {Pt(RNH~2~)~2~(μ‐NHCO__t__Bu)~2~}~2~Cd~2~ is trigonal‐bipyramidal and the Pt−Cd−Pt is bent. Treatment of [Pt(NH~2~CH~2~CH~2~OCH~3~)~2~(NHCO__t__Bu)~2~] with an equimolar amount of AgClO~4~ yielded the Pt~4~Ag~3~ cluster consisting of alternate Pt and Ag atoms either doubly or singly bridged by amidate ligands. The spectroscopic and electrochemical studies show that the metal−metal interactions between platinum and the heterometal ions are very weak. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)