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Abstract: We report the synthesis of trans-dichlorobis(1,3-diaminopropane)ruthenium(III) chloride. The molecular structure consists of a ruthenium metal complex and a chloride counterion. Electronic spectra of the solid complexes indicate an octahedral geometry around the ruthenium(III) metal center. We observe a UV-broadened band at 350nm, a common absorption band in trans-ruthenium(III) amine and haloamine complexes. We also report, the single-crystal X-ray structures of the titled complex. The complex was shown to form a self assembled monolayer on quartz, which is a suitable substrate for deposition of conducting polymer PANI, PEDOT and PPy. We discuss key parameters which can be adjusted to tune both the physical properties of the Ru(III) surfaces and the sheet conductivity of the deposited conducting polymers thin films. [Copyright &y& Elsevier]

Abstract: Mononuclear ruthenium–thiolate complexes of structural type CpRu(PPh3)2SR (1) [R=2-imidazolyl (a), 1-methylimidazolyl (b), 5-methyl-1,3,5-thiadiazolyl (c) and 5-methyl-4H-1,2,4-triazolyl (d)] are accessible from the reaction of CpRu(PPh3)2Cl with the corresponding thiolate anions. Reaction of CpRu(PPh3)2Cl with the heterocyclic-thiolate anions in the presence of the bisphosphine ligands affords CpRu(P–P)SR [P–P=bis(diphenylphosphino)methane; dppm (2), bis(diphenylphosphino)ethane; dppe (3)]. If CO gas was bubbled through a THF solution of 1b, the complex CpRu(PPh3)(CO)S(C4N2H5) (4b) is produced. These ruthenium–heterocyclic thiolate complexes have been characterized by elemental analysis, spectroscopy (IR, 1H, 31P{1H} NMR and MS) and cyclic voltammetry for some samples. The solid-state structures of 3a and 3b are determined by single-crystal X-ray structure analysis. [ABSTRACT FROM AUTHOR]

Abstract: The ruthenium–nitrosyl complexes [RuII(trpy)(tmp)(NO+)](ClO4)3 ([4](ClO4)3) and [RuII(trpy)(tmp)(NO )](ClO4)2 ([5](ClO4)2) with {Ru–NO}6 and {Ru–NO}7 configurations, respectively (trpy=2,2′:6′,2′′-terpyridine, tmp=3,4,7,8-tetramethyl-1,10-phenanthroline) have been isotaled. The nitrosyl complexes [4]3+ and [5]2+ have been generated by following a stepwise synthetic procedure: [RuII(trpy)(tmp)(X)] n , X/n =Cl/+ (1 +)→CH3CN/2+ (2 2+)→NO2/+ (3 +)→NO+/3+ (4 3+)→NO /2+ (5 2+). The single-crystal X-ray structures of two precursor complexes [1]ClO4 and [3]ClO4 have been determined. The DFT optimized structures of 4 3+ and 5 2+ suggest that the Ru–N–O geometries in the complexes are linear (177.9°) and bent (141.4°), respectively. The nitrosyl complexes with linear (4 3+) and bent (5 2+) geometries exhibit ν(NO) frequencies at 1935cm−1 (DFT: 1993cm−1) and 1635cm−1 (DFT: 1684cm−1), respectively. Complex 4 3+ undergoes two successive reductions at 0.25V (reversible) and −0.48V (irreversible) versus SCE involving the redox active NO function, RuII–NO+ ⇄RuII–NO and RuII–NO →RuII–NO−, respectively, besides the reductions of trpy and tmp at more negative potentials. The DFT calculations on the optimized 4 3+ suggest that LUMO and LUMO+1 are dominated by NO+ based orbitals of around 65% contribution along with partial metal contribution of ∼25% due to (dπ)RuII →π∗(NO+) back-bonding. The lowest energy transitions in 4 3+ and 5 2+ at 360nm and 467nm in CH3CN (TD-DFT: 364 and 459nm) have been attributed to mixed MLLCT transitions of tmp(π)→NO+(π∗), Ru(dπ)/tmp(π)→NO+(π∗) and Ru(dπ)/NO (π)→trpy(π∗), respectively. The paramagnetic reduced species 5 2+ exhibits an anisotropic EPR spectrum with g 1 =2.018, g 2 =1.994, g 3 =1.880 (〈g〉=1.965 and Δg =0.138) in CH3CN, along with 14N (I=1) hyperfine coupling constant, A2=35G at 110K due to partial metal contribution in the singly occupied molecular orbital (DFT:SOMO:Ru (34%) and NO (53%)). Consequently, Mulliken spin distributions in 5 2+ are calculated as 0.115 for Ru and 0.855 for NO (N, 0.527; O, 0.328). The reaction of moderately electrophilic nitrosyl center in 4 3+ with the nucleophile, OH− yields the nitro precursor, 3 + with the second-order rate constant value of 1.7×10−1 M−1 s−1 at 298K in CH3CN–H2O (10:1). On exposure to light (Xenon 350W lamp) both the nitrosyl species, 4 3+ ({RuII–NO+}) and 5 2+ ({RuII–NO }) undergo photolytic Ru–NO bond cleavage process but with a widely varying k NO, s−1 (t 1/2, s) of 1.56×10−1(4.4) and 0.011×10−1(630), respectively. [Copyright &y& Elsevier]

Abstract: The previously reported complex [Ru(ttpy)(CN)3]− [ttpy=4′(p-tolyl)-2,2′:6′,2″-terpyridine] is conveniently synthesised by reaction of ttpy with Ru(dmso)4Cl2 to give [Ru(ttpy)(dmso)Cl2], which reacts in turn with KCN in aqueous ethanol to afford [Ru(ttpy)(CN)3]− which was isolated and crystallographically characterised as both its (PPN)+ and K+ salts. The K+ salt contains clusters containing three complex anions and three K+ cations connected by end-on and side-on cyanide ligation to the K+ ions. The solution speciation behaviour of [Ru(ttpy)(CN)3]− was investigated with both Zn2+ and K+ salts in MeCN, a solvent sufficiently non-competitive to allow the added metal cations to associate with the complex anion via the externally-directed cyanide lone pairs. UV–Vis spectroscopic titration of (PPN)[Ru(ttpy)(CN)3] with Zn(ClO4)2 showed a blue shift of 2900cm−1 in the 1MLCT absorption manifold due to the ‘metallochromism’ effect; a series of distinct binding events could be discerned corresponding to formation of 4:1, 1:1 and then 1:3 anion:cation adducts, all with high formation constants, as the titration proceeded. In contrast titration of (PPN)[Ru(ttpy)(CN)3] with the more weakly Lewis-acidic KPF6 resulted in a much smaller blue-shift of the 1MLCT absorptions, and the titration data corresponded to formation of 1:1 and then 2:1 cation:anion adducts with weaker stepwise association constants of the order of 104 and then 103 M−1. Although association of [Ru(ttpy)(CN)3]− resulted in a blue-shift of the 1MLCT absorptions, the luminescence was steadily quenched, as raising the 3MLCT level makes radiationless decay via a low-lying 3MC state possible. [Copyright &y& Elsevier]

Abstract: In an unusual reaction of H2L2 (H2L2 =N-heteropentacene) with Ru(PPh3)3Cl2 a phospho-ylide ruthenium(II) complex (1) was obtained via unprecedented chemical transformations of the conjugate base [L2]2−. A bidentated phospho-ylide ligand is formed with concomitant aromatic ring hydroxylation and new C–P bond formation reactions. The new ligand, binds to RuII as a neutral N, O-donor. Crystal structure determination by single crystal X-ray diffraction has been used to characterize the compound. The phospho-ylide Ru(II) description of the complex was established based on 13C as well as 31P NMR studies. The complex shows rich spectral and redox properties. UV–Vis–NIR spectrum consisted of multiple low-energy transitions in the visible and near IR regions. Preliminary density functional theory calculations were employed to understand the electronic structure and to assign the spectral transitions. Cyclic voltammogram and EPR-spectrum of the electrogenerated oxidized compound are reported and used to characterize the redox properties. [ABSTRACT FROM AUTHOR]

Abstract: Reactions of 1-{[2-(arylazo)phenyl]iminomethyl}-2-phenol, HLsal, 1, [where H represents the dissociable protons upon complexation and aryl groups of HLsal are phenyl for HL1 sal, p-methylphenyl for HL2 sal, and p-chlorophenyl for HL3 sal], ligands with Ru(H)(CO)(Cl)(PPh3)3 afforded complexes of composition [(Lsal)Ru(CO)(Cl)(PPh3)] and (Lsal)2Ru where the N,N,O donor tridentate (Lsal)− ligands coordinated the metal centre facially and meridionally, respectively. Stepwise formation of [(Lsal)2Ru] has been ascertained. Reaction of 1-{[2-(arylazo)phenyl]iminomethyl}-2-napthol, HLnap, 2, [where H represents the dissociable protons upon complexation and aryl groups of HLnap are phenyl for HL1 nap, p-methylphenyl for HL2 nap, and p-chlorophenyl for HL3 nap], ligands with Ru(H)(CO)(Cl)(PPh3)3 afforded exclusively the complexes of composition [(Lnap)Ru(CO)(Cl)(PPh3)], where N,N,O donor tridentate (Lnap)− was facially coordinated. The ligand 1-{[2-(phenylazo)phenyl]aminomethyl}-2-phenol, HL, 3, was prepared by reducing the aldimine function of HL1 sal. Reaction of HL with Ru(PPh3)3Cl2 afforded new azosalen complex of Ru(III) in concert with regiospecific oxygenation of phenyl ring of HL. All the new ligands were characterized by analytical and spectroscopic techniques. The complexes were characterized by analytical and spectroscopic techniques and subsequently confirmed by the determination of X-ray structures of selected complexes. [ABSTRACT FROM AUTHOR]

Abstract: Ruthenium complexes [Ru(mpy)2(DMSO)2] (1) and [Ru(mbtz)2(DMSO)2] (2) containing 2-mercaptopyridine (mpy) and 2-mercaptobenzothiazole (mbtz) have been synthesized. Reactivity of 1 have been examined with 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), EPh3 (E=P, As) and 1,2-bis(diphenylphosphino)-methane (dppm). It reacted with bipy or phen in DMF to afford [Ru(mpy)2(bipy)] (3) and [Ru(mpy)2(phen)] (4) while, its reaction with EPh3 or dppm in common organic solvents failed to afford products containing EPh3 or dppm. Complexes under investigation have been characterized by elemental analyses, spectral, electrochemical studies and structures of 1–4 have been determined crystallographically. Density functional theory calculations have been performed on 1–4 and the model complex [Ru(mpy)(PMe3)2] (5) using exchange correlation functionals BP86. Optimized bond length and angles are in good agreement with the structural data. The Ru–N and Ru–S bond distances in [Ru(mpy)2]-moiety of 1 are relatively shorter than 5, indicating higher stability of 1 in comparison to 5. The WBI values of Ru–N1, Ru–N2, Ru–S1 and Ru–S2 bonds indicate Ru–mpy bonding trend as 3 > 4 > 1 > 5. There is an overall charge flow in the direction L→[Ru(mpy)2] (L=DMSO, bipy, phen and PMe3). Due to greater ionic character and Pauli repulsive interactions for Ru–PMe3 bond in comparison to Ru–DMSO, the DMSO ligands in 1 may not be substituted by phosphine ligands experimentally. [Copyright &y& Elsevier]

Abstract: Both the trans and cis isomers of [Ru(acac)2{P(OMe)3}2] were isolated in the form of single crystals and characterized by single crystal X-ray diffraction, UV–Vis, MS, 1H, 13C and 31P NMR spectroscopy. The compounds of ruthenium(II), both mononuclear complexes, crystallize in triclinic space group. The metal ion in both compounds has similar, slightly distorted octahedral coordination geometry. Both complexes were tested as catalyst in hydrogen generation from the hydrolysis of sodium borohydride. When used alone, none of the trans- and cis-[Ru(acac)2{P(OMe)3}2] complexes shows significant catalytic activity. However, the catalytic activity of cis-[Ru(acac)2{P(OMe)3}2] in the hydrolysis of sodium borohydride is significantly enhanced by the addition of two equivalents of trimethylphosphite per ruthenium into the medium. [Copyright &y& Elsevier]

Abstract: Preparation and characterization of (triphenylphosphine)ruthenium complexes bearing N,O,N′-tridentate ligands, [(L1)RuCl(PPh3)2](BF4) (L1 =2-[(2-pyridylmethoxy)methyl]pyridine), 1), [(L2)RuCl(PPh3)2](BF4) (L2 =8-(2-pyridylmethoxy)quinoline, 2) and [(L3)RuCl2(PPh3)] (L3 =2-[(2-pyridylmethoxy)methyl]quinoline, 3) are described. Complexes 1–3 have been characterized by NMR and elemental analyses. Molecular structures of 2 and 3 have been determined by X-ray crystallography. Both compounds exhibit the octahedral geometry. L2 adopts the facial configuration in 2 while L3 is in a mer-arrangement in 3. Complexes 1–3 have proven to be able to catalyze the transfer hydrogenation of several ketones to alcohols in the presence of KOH and 2-propanol at refluxing, among which complex 3 was found to be the most active. [Copyright &y& Elsevier]

Abstract: The reaction of ruthenium carbonyl polymer ([Ru(CO)2Cl2] n ) with azopyridyl compounds (2,2′-azobispyridine; apy or 2-phenylazopyridine; pap) generated new complexes, [Ru(azo)(CO)2Cl2] (azo=apy, pap). [Ru(apy)(CO)2Cl2] underwent photodecarbonylation to give a chloro-bridged dimer complex, whereas the corresponding pap complex ([Ru(pap)(CO)2Cl2]) was not converted to a dimer. The reactions of the chloro-bridged dimer containing the bpy ligand (bpy=2,2′-bipyridine) with either apy or pap resulted in the formation of mixed polypyridyl complexes, [Ru(azo)(bpy)(CO)Cl]+. The novel complexes containing azo ligands were characterized by various spectroscopic measurements including the determination of X-ray crystallographic structures. Both [Ru(azo)(CO)2Cl2] complexes have two CO groups in a cis position to each other and two chlorides in a trans position. The azo groups are situated cis to the CO ligand in [Ru(azo)(bpy)(CO)Cl]+. All complexes have azo N–N bond lengths of 1.26–1.29Å. The complexes exhibited azo-based two-electron reduction processes in electrochemical measurements. The effects of introducing azopyridyl ligands to the ruthenium carbonyl complexes were examined by ligand-based redox potentials, stretching frequencies and force constants of CO groups and bond parameters around Ru–CO moieties. [Copyright &y& Elsevier]

Abstract: The bifunctional material [RuNO(en)2Cl]3[Cr(OH)6 Mo6O18]2 ·17H2O (en – ethylenediamine), comprisingphotochromic and paramagnetic molecular blocks, have been synthesised. The crystal structure, photochromic and magnetic properties of the compound have been investigated. [Copyright &y& Elsevier]

Abstract: The new trans-hyponitrite derivative complex [Ru2(CO)4(μ-P t Bu2)(μ-dppm)(μ-η2-ONNOMe)] (2, dppm=Ph2PCH2PPh2) was prepared by deprotonation of [Ru2(CO)4(μ-H)(μ-P t Bu2)(μ-dppm)(μ-η2-ONNOMe)][BF4] (1) with the base DBU (1.8-diazabicyclo[5.4.0]undec-7-ene). The latter complex salt has been obtained in an improved synthesis starting from the trans-hyponitrite complex [Ru2(CO)4(μ-H)(μ-P t Bu2)(μ-dppm)(μ-η2-ONNO)]. Compound 2 has been characterized by spectroscopic methods as well as by X-ray diffraction and represents the first neutral complex bearing a deprotonated monoester of the hyponitrous acid as the bridging ligand. [Copyright &y& Elsevier]