Synthesis and reactivity of the non-bridged metal-metal bonded rhodium octamethoxyporphyrin dimer

Electron-rich rhodium porphyrin alkyls (omp)RhR (R = Me, Pr-i, omp = 2,3,7, 8,12,13,17,18-octamethoxyporphyrin dianion) were photolyzed to give the non -bridged metal-metal bonded complex Rh-2(omp)(2). Reaction of (omp)RhH with TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) also yielded Rh-2(omp)(2) qua ntitatively. Rh-2(omp)(2) reacted with CH3I to produce (omp)RhMe and (omp)R hI, and with Et3SiH to give (omp)RhSiEt3, and (omp)RhH in 42-52% yield, res pectively. Addition of Rh-2(omp)(2) with styrene yielded phenylethyl-bridge d complexes, (omp)RhCH2CH(Ph)Rh(omp). Rh-2(omp)(2) reacted with triphenylph osphine to produce the cationic and anionic Rh-III species of [(omp)Rh](+) and [(omp)Rh](-). (C) 1999 Elsevier Science S.A. All rights reserved.