T. Nyokong, CYCLIC VOLTAMMETRY AND SPECTROELECTROCHEMISTRY OF RHODIUM PHTHALOCYANINES, Journal of the Chemical Society. Dalton transactions, (9), 1994, pp. 1359-1365
The electrochemistry of Rh(III)(pc) (pc = phthalocyanine dianion) comp
lexes containing chloride, pyridine, dimethyl sulfoxide (dmso) and cya
nide as axial ligands was investigated by cyclic voltammetry and UV/VI
S spectroelectrochemistry. The compounds were K[Rh(pc)(CN)2], [Rh(pc)(
Cl)(py)] and [Rh(pc)CI(dmso)]. For all of these the first oxidation oc
curs at the phthalocyanine ligand with the formation of a pi-cation ra
dical species. The addition of one electron to the complexes leads to
one of two different reduction products depending on the nature of the
axial ligands. The first reduction of [Rh(pc)Cl(py)] and [Rh(pc)Cl(dm
so)] occurs at the metal, followed by rapid dimerization of the reduce
d species. The first and subsequent reductions of K[Rh(pc)(CN)2] occur
at the ring.