Paramagnetic one-dimensional chains containing high-spin manganese atoms showing antiferromagnetic interaction through -Pt-Rh-Rh-Pt- bonds.

To exploit the magnetic interactions of multiple metals, a heterometallic one-dimensional (1D) chain containing three kinds of metals, Rh, Pt, and Mn, where [Rh 2 (O 2 CCH 3 ) 4 ] and [Pt 2 Mn(piam) 4 (NH 3 ) 4 ] 2+ (piam = pivalamidate) are connected through unbridged Rh-Pt bonds to form -Rh-Rh-Pt-Mn-Pt- alignments was successfully synthesized. The Mn atoms are tetrahedrally coordinated by four oxygen atoms of the piam ligands, where the coordination geometries form a zigzag 1D chain. Each Mn atom is linked by -Pt-Rh-Rh-Pt-, with a Mn-Mn separation of 13.9 Å. In parent [Pt 2 Mn(piam) 4 (NH 3 ) 4 ](PF 6 ) 2 , Mn adopts two coordination environments, octahedral and tetrahedral, both of which are Mn(+2) high-spin states. In EtOH, [Rh 2 (O 2 CCH 3 ) 4 ] selectively binds tetrahedral Mn to afford a 1D chain. Physical analysis of the 1D chain using electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) revealed that all metals are divalent, indicating five unpaired spin-localized electrons on the Mn atoms. Magnetic susceptibility measurements indicated antiferromagnetic intra-chain interactions between the Mn atoms in the 1D chain, where χT at 300 K was 5.33 cm 3 K mol -1 and gradually decreased to 1.65 cm 3 K mol -1 at 2 K. Theoretical fitting of the magnetic behavior showed weak exchange coupling ( zJ = -0.43 cm -1 ) between two high-spin Mn(+2) ions through diamagnetic Pt-Rh-Rh-Pt.