CYCLOMETALLATION REACTIONS IN COMPLEXES OF THE TYPE Rh(oq)(CO). THE MOLECULAR STRUCTURE OF (oq = 8-hydroxyquinolinate)

Article abstract of DOI:10.1016/0022-328X(84)80382-4

Cyclometallation occurs when a solution of the complex Rh(oq)(CO)(PCBr), (PCBr = 2-bromo-3,4,5,6-tetraffluorophenyldiphenylphosphine; oq = 8-hydroxyquinolinate) in toluene is refluxed, giving (PC = P(C6F4)(C6H5)2) and a dimeric compound, not yet completely characterized, formulated as Rh2Br(oq)(PCBr)2. was characterized by elemental analysis, by conductance measurements, and by 19F, 31P NMR and infrared spectroscopy.Its molecular structure was determined by single-crystal X-ray methods and refined by standard procedures to final agreement factors R and R_w of 0.067 and 0.060 for 5346 observed data.Lattice constants are 15.8494(6), 14.7188(5), 14.6675(5) Angstroem and β 96.933(3) deg, with monoclinic symmetry.The complex has a distorted octahedral geometry with a four atom metallocycle-ring (Rh-P-C-C) showing distorted angles of 69.8(2) and 84.8(2) deg at Rh and P atoms, respectively.The analogous compound , (5-moq = 5-methyl-8-hydroxyquinolinate), can be obtained by heating Rh(5-moq)(CO)(PCBr).