A paramagnetic quasi-1D chain comprised of Pt/Rh possessing an unpaired electron

In this manuscript we review the structure of the novel 1-D chain complex, {[PtRh(PVM)2(NH3)2Cl2.5]2[Pt2(PVM)2(NH3)4]2(PF6)6·2MeOH·2H2O}n (4) (PVM=pivalamidate), consisting of mixed-valence dimeric complexes with appreciably extended metal-metal bondings. Compound 4 is made up of octameric segments, each of which consists of two platinum-rhodium dinuclear complexes and a tetrameric platinum unit. The charge of 19+ for the Pt6Rh2 octameric segment in 4 was deduced from the number of the independent PF6− counter ions, and is the supporting evidence for one unpaired electron per one octameric segment. The tetrameric platinum unit in 4 is the structural motif that is observed in [Pt2(PVM)2(NH3)4](PF6)2·H2O (2) and [Pt4(PVM)4(NH3)8](PF6)4(ClO4)·2H2O (3=“platinum blue” with one electron delocalized over the four platinum atoms). On the basis of the EPR, magnetic susceptibility, and electrical conductivity results, the nature of the unpaired electron in 4 is discussed.