Heterotrimetallic Complexes [{Pt(RNH₂)₂(μ‐NHCO<i>t</i>Bu)₂}₂M](ClO₄)_<i>n</i> (M = Mn, Co, Cu, Ni, Cd, and Zn, <i>n</i> = 2; M = In, <i>n</i> = 3), [{Pt(NH₃)(μ‐DACHCO<i>t</i>Bu)(μ‐NHCO<i>t</i>Bu)}₂Ni](ClO₄)₂, and [{Pt(RNH₂)₂(NHCO<i>t</i>Bu)₂}₃Ag₃](ClO₄)₃ Bridged by Amidate Ligands: A Novel Amidate−Amine Interligand Reaction During the Pt−Ni Bond Formation

Abstract

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 ](ClO 4 ) 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](ClO 4 ) 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](ClO 4 ) 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](ClO 4 ) 2 . The central Cd ion in [{Pt(RNH 2 ) 2 (μ‐NHCO t Bu) 2 } 2 Cd](ClO 4 ) 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 &amp; Co. KGaA, 69451 Weinheim, Germany, 2003)