title: Organobimetallic Ru(II)-Re(I) 4-ethynylpyridyl complexes: structures and non-linear optical properties.
abstract: A series of heterobimetallic complexes, [RuCp(C[triple bond]Cpy-4)(P-P)][Re(CO)3(N-N)]+ (P-P = dppf, N-N = bpy 5, Me2bpy 6, tBu2bpy 7, phen 8, tpy 9; P-P = 2PPh3, N-N = bpy 10) have been obtained from Lewis addition between the metalloligands [RuCp(C[triple bond]Cpy-4)(P-P)] (P-P = dppf 1; 2PPh3 2) and solvent-stabilised fac-[Re(CH3CN)(CO)3(N-N)]+. All new complexes 5-10, together with fac-[ReBr(CO)3(tpy)] (3) and fac-[Re(CH3CN)(CO)3(tpy)][PF6] (4), are characterized by solution spectroscopy; 3 and 5-9 are also characterized by single-crystal X-ray crystallography. The terpyridine ligands in 3 and 9 are in an unusual 2-bidentate coordination mode with a pendant pyridyl. Electrochemical studies showed successive metal-based oxidations and a ligand-centered reduction in 5-10. Significant oxidation changes are observed at the Ru(II) and Re(I) centers in 5-10 when compared with their respective monometallic components. Cubic nonlinearities of 5-10 determined by the Z-scan technique at 750 nm reveal two-photon absorption that increases significantly on progression from Ru(II) monomeric precursors to heterobimetallics, suggesting NLO enhancement upon heterometallic complex formation.
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543.
authors.forename: Qingchun
authors.initials: Q
authors.lastname: Ge
authors.forename: T Christopher
authors.initials: TC
authors.lastname: Corkery
authors.forename: Mark G
authors.initials: MG
authors.lastname: Humphrey
authors.forename: Marek
authors.initials: M
authors.lastname: Samoc
authors.forename: T S Andy
authors.initials: TS
authors.lastname: Hor
mesh_terms: D018360:Crystallography, X-Ray; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D012211:Rhenium / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D009942:Organometallic Compounds; D011725:Pyridines; D012211:Rhenium; D012428:Ruthenium