2,2′-Bipyridyl and o-phenanthroline carbonyl complexes of rhodium

CO was passed through an alc. soln. of Rh perchlorate contg. 2,2'-bipyridine (L) or o-phenanthroline (L1) to give [Rh(CO)2L]ClO4 (I), m. 200-5°, and [Rh(CO)2L1]ClO4 (II), m. 195-200°, resp. With PPh3 and AsPh3 under similar conditions, [Rh(CO)2(PPh3)3]ClO4 (III), m. 160-2°, and [Rh(CO)2(AsPh3)3]ClO4 (IV), m. 198-9°, resp., were obtained. I and II were also obtained by passing CO through a hot alc. soln. of RhCl3.3H2O until the soln. turned yellow and then adding at ice temp., an excess of NaClO4 and L or L1, resp. I and II in EtOH were treated with PPh3 to give [Rh(CO)L(Ph3P)2]ClO4, m. 150-2°, and [Rh(CO)L1(Ph3P)2]ClO4, m. 148-53°, resp. These latter 2 compds. were also obtained by the addn. of L or L1 to an EtOH soln. contg. III. Similarly prepd. was [Rh(CO)L(Ph3As)2]ClO4, m. 205-8°. The complexes were characterized by elemental anal., ir spectra, and cond. measurements. I, II, III, and IV react with Ph3PO in excess releasing all CO present