Rhodium(I) carbonyl complexes with [alpha]-diimine ligands containing amino or hydroxy substituents

• Published in: Transition metal chemistry (Weinheim) 1999-08, Vol.24 (4), p.394
• Main Authors: Bikrani, Mohammed, Fidalgo, M Luz, Garralda, María A, Ibarlucea, Lourdes
• Format: Article
• Language: English
• ISSN: 0340-4285; 1572-901X
• DOI: 10.1023/A:1006961602543

α-Diimines, RN:C(R')C(R'):NR''(LL) derived from glyoxal, GLL (R'=H) abbreviated as GAA (R= R''=4-dimethylaminophenyl) or GHA (R= R''=4-hydroxyphenyl), and derived from biacetyl, BLL (R'=Me) abbreviated as BDH (R=R''= NH^sub 2^), BOH (R=NH^sub 2^, R''=OH) react with carbonylrhodium(I) compounds to give different products depending on the imino substituents in the ligand and/or the solvent employed. The reaction of α-diimines bearing amino groups, such as GAA or BDH with [RhCl(CO)^sub 2^]^sub 2^ in acetone yields binuclear [RhCl(CO)^sub 2^]^sub 2^(μ-LL) while in CH^sub 2^Cl^sub 2^ ionic [Rh- (CO)^sub 2^(LL)]^sup +^[RhCl^sub 2^(CO)^sub 2^]^sup -^ species are obtained. In acetone [RhCl(CO)^sub 2^]^sub 2^(μ-GAA) exists as an equilibrium mixture between two different neutral binuclear species; [Rh(CO)^sub 2^(BDH)]^sup +^ exists as a mixture of two species containing chelate or monodentate bonded diimine respectively. GAA or BDH react "in situ" with [RhCl(CO)(C^sub 2^H^sub 4^)]^sub 2^ in benzene to yield tetracoordinated monocarbonylated [RhCl(CO)(LL)] compounds. α-Diimines (LL) bearing hydroxy groups, such as GHA or BOH react with [RhCl(CO)^sub 2^]^sub 2^ or "[RhCl(CO)(C^sub 2^H^sub 4^)]^sub 2^" to give pentacoordinated dicarbonylated [RhCl(CO)^sub 2^(LL)] compounds.[PUBLICATION ABSTRACT]