Evidence of electronic interactions between end platinum atoms of hexanuclear units in heterometallic one-dimensional chains

Abstract In this study, [{Rh2(O2CCF3)4}{Pt2(piam)2(NH2CH3)4}2](CF3SO3)4·2H2O (2f, piam = pivalamidate), which is a one-dimensional (1D) hexanuclear complex aligned as Pt–Pt–Rh–Rh–Pt–Pt, was successfully synthesized and characterized. When [Pt2(piam)2(NH3)4]2+ was mixed with [Rh2(O2CCF3)4], infinite 1D [{Rh2(O2CCF3)4}{Pt2(piam)2(NH3)4}2]n(CF3CO2)4n·2nEtOH·2nH2O (1f) chains, aligned as –{Pt–Pt–Rh–Rh–Pt–Pt}n–, were obtained, where the end platinum atoms were separated from neighboring end platinum atoms by a distance of 3.0791(15) A. The diffuse reflectance spectra revealed two absorptions at 2.67 and 2.23 eV in 1f, which are attributed to transitions between σ-type orbitals, and a single absorption at 2.77 eV in 2f chains. These results prove that 1f forms a band structure due to metal–metal bonds formed along the 1D heterometallic chain.