Synthesis and P-31 NMR caracterization of substituted carbonylcobalt(I) complexes

Reactions of (C6 F5 )Co(C0) 4 (I) with equimolar amounts of different phosphorus donors give monosubstituted complexes (C6 F5 )Co(C0) 3 L being L = PEt 3-(II), P-n­ But3 (III), PPh 3 (IV), PMe2 Ph (V), PMePh 2 (VI), P(OMe), (VII), P(OEt), (VIII), and P(OPh) 3 (IX). Complexes II-IV as well as the dimer (C6 F5 )Co(C0) 3PPh 2- (CH2 )2PPhi(C0)3Co(C6 F5 ) (X) have been previously described. When the same reactions are made using an excess of the ligand, the disubstituted species (C6 F5 )Co(CO),L 2 are isolated, being L = PEt 3 (XI), P-n-But 3 (XII), PPh 3 (XIII), PMe2 Ph (XIV), PMePh 2 (XV), P(OMe) 3 (XVI), P(OEt) 3 (XVII) and P(OPh 3 ) (XVIII). The mononuclear compound XIX with the bidentate ligand PPh 2 (CH 2 ) 2 PPh 2 only could be obtained by reducing (C6F5 ) 2Co(PPh 2 (CH2 ) 2 PPh 2 ) with NaBH 4 under CO. The IR and 31 P NMR spectra of all these compounds permit to make a structural assignment.The authors greatly appreciate the financial support received from Comisión Asesora de lnvestigación Científica y Técnica (Spain)