Construction of Heterometallic One‐Dimensional Chain with δ* in the HOMO Using Quadruple Hydrogen Bonds

Abstract Mixing [Rh 2 (acam) 4 ] (acam=acetamidate) with pivalic acid yielded Head and Tail‐[Rh 2 (acam) 2 (OPiv) 2 ] ( 1 , where PivOH denotes pivalic acid). The highest occupied and lowest unoccupied molecular orbitals were determined through cyclic voltammetry, electron paramagnetic resonance of the one‐electron oxidized form, and density functional theory calculations. Compound 1 and [Pt 2 (piam) 2 (NH 3 ) 4 ](PF 6 ) 2 (piam=pivalamidate) formed Rh−Pt bonds, yielding a heterometallic one‐dimensional chain [{Rh 2 (acam) 2 (OPiv) 2 }{Pt 2 (piam) 2 (NH 3 ) 4 }] n (PF 6 ) 2 n ( 2 ), where both complexes are aligned in a repeating pattern. As the Rh atom is equatorially coordinated with one hydrogen‐bond donor nitrogen and three hydrogen‐bond acceptor oxygens, and the Pt atom is coordinated with three nitrogens and one oxygen, quadruple complementary hydrogen bonds effectively support Rh−Pt bonds. The diffuse reflection spectrum of 2 shows three absorption peaks at E 1 (3.13 eV), E 2 (1.71 eV), and E 3 (1.41 eV), which are characteristic of the Rh−Pt bond, indicating the formation of band structure along the one‐dimensional direction.