Marcelo O. Santiago

Electrochemical and spectroscopic studies on RuCl2(PPh3)2(N)2 and RuCl2(PPh3)2(N–N) complexes (N=pyridine derivatives and N–N=phenanthroline or bipyridine derivatives). X-ray structure of RuCl2(PPh3)2(phen)

Abstract A series of RuCl2(PPh3)2(N)2 and RuCl2(PPh3)2(N–N) complexes were synthesized from RuCl2(PPh3)3, (N)2=pyridine (py), 4-(N,N-dimethylamino)pyridine (4-dmNpy), 4-tert-butylpyridine (4-tBu-py), 4-methylpyridine (4-Mepy), 4-vinylpyridine (4-Vpy), 4-phenylpyridine (4-Phpy), isonicotinamide (4-CONH2py), 4-cyanopyridine (4-CNpy) N–N=1,10-phenanthroline (phen), 2,2′-bipyridine (bipy), 2,2′-bipyridine-4,4′-dimethoxy (MeO-bipy), 2,2′-bipyridine-4,4′-dimethyl (Me-bipy), 2,2′-bipyridine-4,4′-dithiomethyl (MeS-bipy), 2,2′-bipyridine-4,4′-dichloro (Cl-bipy) and 2,2′-bipyridine-4,4′-dinitro (NO2-bipy). The complexes were characterized by elemental analysis, cyclic voltammetry and UV–Vis, NMR and IR spectroscopies. The structure of the RuCl2(PPh3)2(phen) was established by single crystal X-ray crystallography.

On the correlation between electronic intramolecular delocalization and Au-S bonding strength of ruthenium tetraammine SAMs

Trans-[Ru(L)(NH3)4(L’)](PF6)n type complexes, where L = 4-cyanopyridine (CNpy), NCS-, CN-, and L’ = CNpy, 1,4-dithiane (1,4-dt), 4-mercaptopyridine (pyS) and thionicotinamide (tna), were synthesized and characterized. SAMs on gold of the complexes containing sulfur were studied by reductive desorption and SERS spectroscopy. Depending on the nature of L’, the withdrawing capability of the CNpy ligand is strong enough to partially oxidize the ruthenium atom and, as a consequence, delocalize the s electronic density from the trans located ligand. The reductive desorption results showed that the stability of the SAMs is directly related to this effect.

Synthesis, Structural, Spectroscopic and Electrochemical Characterization of New Ruthenium(II) Tetramer Complexes Containing 1,4-Bis(diphenylphosphine)butane and Alterdentate Ligands

In this work a series of {[RuCl2(dppb)](μ-4,4′-N-N)}4 complexes were synthesized and characterized by elemental analysis, cyclic voltammetry and differential pulse voltammetry and UV–Vis and 31P{1H} NMR spectroscopies; [(μ-4,4′-N-N=pyrazine (pz), 4,4′-bipyridine=(4,4′-bipy), 1,2-bis-trans-(4-pyridyl)ethane = (pyeta) and 1,2-bis-trans-(4-pyridyl)ethylene=(pyetil) as bridging alterdentate ligands (alterdentate ligands are molecules (or ions), with two equivalent ligating atoms or ligating sites that do not simultaneously bind to a metallic center [Zelewsky von A. in Stereochemistry of Coordination Compounds, Inorganic Chemistry, A Textbook Series; John Wiley & Sons, Inc.: New York, 1995: p. 45] [1]) and 1,4-bis(diphenylphosphino)butane=dppb]. Electrochemical experiments (cyclic voltammetry and differential pulse voltammetry) suggest that for longer ligands the interaction between two ruthenium atoms is weak and for short ligands like pyrazine the corresponding interaction is strong. The analysis of the X-ray structure of the {[RuCl2(dppb)](μ-4,4′-bipy)}4 complex showed that the molecular squares obtained are stacked on top of each other along the α axis forming infinite columns and that the formation of central tunnels is prevented by the bulky character of the phenyl groups of the diphenylphosphine ligands.

Electrochemical and spectroscopic studies on RuCl(PPh3)2(N)2 and RuCl2(PPh3)2((N-N)

Abstract A series of RuCl2(PPh3)2(N)2 and RuCl2(PPh3)2(N–N) complexes were synthesized from RuCl2(PPh3)3, (N)2=pyridine (py), 4-(N,N-dimethylamino)pyridine (4-dmNpy), 4-tert-butylpyridine (4-tBu-py), 4-methylpyridine (4-Mepy), 4-vinylpyridine (4-Vpy), 4-phenylpyridine (4-Phpy), isonicotinamide (4-CONH2py), 4-cyanopyridine (4-CNpy) N–N=1,10-phenanthroline (phen), 2,2′-bipyridine (bipy), 2,2′-bipyridine-4,4′-dimethoxy (MeO-bipy), 2,2′-bipyridine-4,4′-dimethyl (Me-bipy), 2,2′-bipyridine-4,4′-dithiomethyl (MeS-bipy), 2,2′-bipyridine-4,4′-dichloro (Cl-bipy) and 2,2′-bipyridine-4,4′-dinitro (NO2-bipy). The complexes were characterized by elemental analysis, cyclic voltammetry and UV–Vis, NMR and IR spectroscopies. The structure of the RuCl2(PPh3)2(phen) was established by single crystal X-ray crystallography.

Electrochemical and spectroscopic studies on RuCl 2 (PPh 3 ) 2 (N) 2 and RuCl 2 (PPh 3 ) 2 (N–N) complexes (N=pyridine derivatives and N–N=phenanthroline or bipyridine derivatives). X-ray structure of RuCl 2 (PPh 3 ) 2 (phen)

Abstract A series of RuCl2(PPh3)2(N)2 and RuCl2(PPh3)2(N–N) complexes were synthesized from RuCl2(PPh3)3, (N)2=pyridine (py), 4-(N,N-dimethylamino)pyridine (4-dmNpy), 4-tert-butylpyridine (4-tBu-py), 4-methylpyridine (4-Mepy), 4-vinylpyridine (4-Vpy), 4-phenylpyridine (4-Phpy), isonicotinamide (4-CONH2py), 4-cyanopyridine (4-CNpy) N–N=1,10-phenanthroline (phen), 2,2′-bipyridine (bipy), 2,2′-bipyridine-4,4′-dimethoxy (MeO-bipy), 2,2′-bipyridine-4,4′-dimethyl (Me-bipy), 2,2′-bipyridine-4,4′-dithiomethyl (MeS-bipy), 2,2′-bipyridine-4,4′-dichloro (Cl-bipy) and 2,2′-bipyridine-4,4′-dinitro (NO2-bipy). The complexes were characterized by elemental analysis, cyclic voltammetry and UV–Vis, NMR and IR spectroscopies. The structure of the RuCl2(PPh3)2(phen) was established by single crystal X-ray crystallography.