Structure of binuclear Rh(II) carboxylato complexes with 2,2′-bipyridine and an unprecedented rhodium wire with Rh4 5+ core

Structures of rhodium(II) binuclear complexes [Rh2(OOCCH3)2(bpy)2(H2O){(CH3)2CHOH}][B(C6H5)4]2 · H2O (1), [Rh2Cl2(OOCCH3)2(bpy)2] · 2H2O (2), [Rh2Br2(OOCCH3)2(bpy)2] · 3H2O (3), and [Rh2I2(OOCCH3)2(bpy)2] (4), as well as an unprecedented wire with infinite Rh–Rh chain, {[Rh4(μ-OOCH)4(bpy)4](BF4)}n · 0.5nC4H8O2 (5), have been determined and discussed. Mass spectra of complexes [Rh2(OOCMe)2(bpy)2(H2O)2](MeCOO)2 and [Rh2(OOCMe)2(phen)2(H2O)2](MeCOO)2 have showed stability of polynuclear cations with rhodium in oxidation states in the range +1.25 to +1.75.