Structures and Properties of 4-phpy, pyz, and 4,4′-bpy Adducts of Lantern-Type Dirhodium Complexes with µ-Formamidinato and µ-Carboxylato Bridges

Dinuclear and polymer complexes of 4-phenylpyridine (4-phpy), pyazine (pyz), 4,4′-bipyridine (4,4′-bpy) were prepared by using cis-[Rh2(4-Me-pf)2(O2CR)2] (4-Me-pf- =N,N’-bis(4-methylphenyl)formamidinate anion; R = CF3 CMe3) as precursor dinuclear units. The structures cis-[Rh2II,II(4-Me-pf)2(O2CR)2(4-phpy)2] cis-[Rh2II,III(4-Me-pf)2(O2CCMe3)2(4-phpy)2]BF4 [Rh2II,II(4-Me-pf)2(O2CR)2(L)]n (L pyz 4,4′-bpy) confirmed X-ray crystal structure analyses. In these complexes, the lantern-type core with cis-(2:2) arrangement formamidinato (4-Me-pf-) carboxylato ligands are preserved Rh–Rh distances 2.44–2.47 Å, regardless difference in axial ligand oxidation state Rh2II,II or Rh2II,III. cyclic voltammograms (CVs) CH2Cl2, redox potentials for Rh2II,III/Rh2II,II estimated E1/2 0.07 V −0.28 (vs. Fc+/Fc) cis-[Rh2(4-Me-pf)2(O2CCF3)2(4-phpy)2] cis-[Rh2(4-Me-pf)2(O2CCMe3)2(4-phpy)2], respectively, negatively shifted 0.16 0.12 compared those corresponding parent complexes. results interpreted that interaction 4-phpy makes oxidized easily. complex cis-[Rh2(4-Me-pf)2(O2CCMe3)2(4-phpy)2]BF4 is paramagnetic, which was effective magnetic moment value μeff 1.90 μB at 300 K per Rh2II,III unit (S 1/2). [Rh2(4-Me-pf)2(O2CR)2(L)]n showed Type II gas-adsorption properties N2.