title: Synthesis and structures of ruthenium di- and tricarbonyl complexes derived from 4,5-diazafluoren-9-one.
abstract: Carbon monoxide (CO) has recently been shown to impart beneficial effects in mammalian physiology and considerable research attention is now being directed toward metal-carbonyl complexes as a means of delivering CO to biological targets. Two ruthenium carbonyl complexes, namely trans-dicarbonyldichlorido(4,5-diazafluoren-9-one-κ(2)N,N')ruthenium(II), [RuCl2(C11H6N2O)(CO)2], (1), and fac-tricarbonyldichlorido(4,5-diazafluoren-9-one-κN)ruthenium(II), [RuCl2(C11H6N2O)(CO)3], (2), have been isolated and structurally characterized. In the case of complex (1), the trans-directing effect of the CO ligands allows bidentate coordination of the 4,5-diazafluoren-9-one (dafo) ligand despite a larger bite distance between the N-donor atoms. In complex (2), the cis disposition of two chloride ligands restricts the ability of the dafo molecule to bind ruthenium in a bidentate fashion. Both complexes exhibit well defined (1)H NMR spectra confirming the diamagnetic ground state of Ru(II) and display a strong absorption band around 300 nm in the UV.
authors.affiliation: Department of Chemistry, UC Santa Cruz, CA 95064, USA.
authors.forename: Jorge
authors.initials: J
authors.lastname: Jimenez
authors.affiliation: Department of Chemistry, UC Santa Cruz, CA 95064, USA.
authors.forename: Indranil
authors.initials: I
authors.lastname: Chakraborty
authors.affiliation: Department of Chemistry, UC Santa Cruz, CA 95064, USA.
authors.forename: Pradip
authors.initials: P
authors.lastname: Mascharak
mesh_terms: D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D005449:Fluorenes / Q000737:chemistry*; D006860:Hydrogen Bonding; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D011789:Quantum Theory; D012428:Ruthenium / Q000737:chemistry*; D017975:Ruthenium Compounds
chemical_list: D056831:Coordination Complexes; D005449:Fluorenes; D008024:Ligands; D017975:Ruthenium Compounds; C000605360:fac-tricarbonyldichlorido(4,5-diazafluoren-9-one-kappaN)ruthenium(II); C000605358:trans-dicarbonyldichlorido(4,5-diazafluoren-9-one-kappa(2)N,N')ruthenium(II); D012428:Ruthenium
keywords: CO releasing molecules; biological effect; bite distance; crystal structure; metal–carbonyl complexes; mode of binding; ruthenium complexes; therapeutics