Bis-r-(phenyl)-tetrakis-l-(capralactamato)dirhodium(III), formed by oxidative reactions of dirhodium(II) carboxamidates with arylboronic acids promoted by copper(II), exists in two non-interconvertable con-formations. In these conformational isomers the caprolactamate ligands are oriented around dirho-dium(III) as a propeller with apparent C4 symmetry and in a biplanar array. Cyclic voltammetry and spectroelectrochemistry as well as Raman and resonance Raman spectroscopy of the conformationally distinct Rh 2 6+ carboxamidates have been obtained in order to explore the origin of their non-interconver-sion. Differences in their vibrational spectra occur only in the low wavenumber spectral region, but there is a 250 mV difference in oxidation potential between conformational isomers consistent with a substan-tial difference ground state energies. Notably, spectroelectrochemical data show that oxidation does not result in isomerization.