title: Trans/cis isomerization of [RuCl2{H2C=C(CH2PPh2)2)}(diamine)] complexes: synthesis, spectral, crystal structure and DFT calculations and catalytic activity in the hydrogenation of α,β-unsaturated ketones.
abstract: Three complexes of the general formula trans/cis-[Ru((II))(dppme)(N-N)Cl2] {dppme is H2C=C(CH2PPh2)2 and N-N is 1,2-diaminocyclohexane (trans/cis-(1)) and 1-methyl-1,2-diaminopropane (trans-(2)} were obtained by reacting trans-[RuCl2(dppme)2] with an excess amount of corresponding diamine in CH2Cl2 as a solvent. The complexes were characterized by an elemental analysis, IR, (1)H, (13)C and (31)P{1H} NMR, FAB-MS and UV-visible. The trans-(1) (kinetic product) readily isomerizes to the cis-(1) (thermodynamic product) and this process was followed by using (31)P{(1)H} NMR, cyclic voltammetry and UV-vis spectroscopy. The electrochemical studies on complex (1) reveal that the Ru(III)/Ru(II) couples are sensitive to the isomer (trans/cis) formed. The cis-(1) was confirmed by X-ray structure and (31)P{(1)H} NMR. Transfer-hydrogenation reactions for reduction of trans-4-phenyl-3-butene-2-one were conducted using complexes trans/cis-(1) and trans-(2). The electronic spectra of cis/trans-(1) in dichloromethane were calculated with the use of time-dependent DFT methods.
authors.affiliation: Department of Chemistry, AN-Najah National University, Nablus, Occupied Palestinian Territory. Electronic address: warad@najah.edu.
authors.forename: Ismail
authors.initials: I
authors.lastname: Warad
authors.forename: Mousa
authors.initials: M
authors.lastname: Al-Noaimi
authors.forename: Obadah S
authors.initials: OS
authors.lastname: Abdel-Rahman
authors.forename: Firas F
authors.initials: FF
authors.lastname: Awwadi
authors.forename: Belkheir
authors.initials: B
authors.lastname: Hammouti
authors.forename: Taibi B
authors.initials: TB
authors.lastname: Hadda
mesh_terms: D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry* / Q000378:metabolism*; D018360:Crystallography, X-Ray; D003959:Diamines / Q000737:chemistry*; D004563:Electrochemistry; D006865:Hydrogenation; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D017975:Ruthenium Compounds / Q000737:chemistry* / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013816:Thermodynamics
chemical_list: D056831:Coordination Complexes; D003959:Diamines; D007659:Ketones; D017975:Ruthenium Compounds
keywords: Diamine; Diphosphine; Electrochemistry; Hydrogenation; Isomerization; Ruthenium(II)