Synthesis and characterization of iron and ruthenium complexes bearing P–N ligands based on 8-hydroxyquinoline

Abstract

The synthesis of bidentate aminophosphine ligands (PN quin) based on 8-hydroxyquinoline is described. These ligands react with cis-Fe(CO) 4Br 2 to give selectively octahedral complexes of the type cis, cis-Fe(PN quin)(CO) 2Br 2. There is only one isomer formed where the two CO and the two bromide ligands adopt a cis configuration. The reaction of [RuCp(CH 3CN) 3]PF 6 with PN quin ligands affords the halfsandwich complexes [RuCp(PN quin)(CH 3CN)]PF 6 in high isolated yields. Likewise, treatment of [Ru( η 6- p-cymene)( μ-Cl)Cl] 2 with PN quin in the presence of AgCF 3SO 3 affords halfsandwich complexes of the type [Ru( η 6- p-cymene)(PN quin)Cl]CF 3SO 3. All ligands and complexes are characterized by NMR and IR spectroscopy. The X-ray structure of representative compounds is reported. In addition, the relative stability of isomeric structures and conformers of Fe(PN quin-Ph)(CO) 2Br 2 is studied by means of DFT calculations.