Ruthenium(II) 8-quinolinolates: Synthesis, characterization, crystal structure and catalysis in the synthesis of 2-oxazolines

New octahedral ruthenium(II) complexes (1e4) have been synthesized from the reaction of ruthenium(II) precursors [RuHCl(CO)(EPh3)3] (E ¼ P or As) with the bidentate Schiff base ligands, 2-((2,6-dimethylphenylimino)methyl)quinolin-8-ol (L1) and 2-((2,6-diisopropylphenylimino)methyl)quinolin-8-ol (L2) in ethanol. These complexes have been characterized by elemental analyses, IR, UVeVis, 1H, 13C and 31P NMR and ESI-Mass spectroscopy. The molecular structure of the complex [RuCl(CO)(PPh3)2(L2)] (2) was determined by single-crystal X-ray diffraction, which reveals a distorted octahedral geometry around ruthenium(II) ion. The catalytic activity of the new complexes was evaluated for the condensation of nitriles with ethanolamine under solvent free conditions. The processes were operative with aromatic and heteroaromatic nitriles and tolerated several substitutional groups. The studies on the effect of substitution over ligands, coligands, reaction time, temperature and catalyst loading were carried out in order to find the best catalyst in this series of complexes and favorable reaction conditions. A probable mechanism for the catalytic condensation of nitrile has also been proposed. The catalyst was recovered and recycled up to five times without significant loss of its activity

Mixed ligand complexes of ruthenium(III) containing N, O/ N, S donor ligands and triphenylphosphine or triphenylarsine

797-801<span style="font-size:12.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font:minor-latin;="" mso-bidi-font-family:"times="" new="" roman";mso-bidi-theme-font:minor-bidi;="" mso-ansi-language:en-in;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Several new ruthenium(III) complexes of the type [RuX(LL')(EPh3) 3] [X = Cl or Br; LL' = schiff bases, namely, bis(aminophenol)glyoxal (apg), bis(aminophenol)benzil (apb) or bis(aminothiol)glyoxal (atg); E = P or As] have been prepared by the reactions of [RuX3 (EPh3) 3] (X = Cl or Br; E = P or As) or [RuBr3(PPh3)2MeOH)] with schiff bases. In all the reactions the schiff bases behave as binegative tetradentate ligands. The new complexes have been characterised by elemental analyses, spectral (IR, electronic, EPR) and cyclic voltammetry. Based on these studies, an octahedral structure has been proposed for all the complexes. The antifungal activities of some of the ligands and their complexes have also been carried out.</span

Mixed ligand triphenylphosphine/arsine Schiff base complexes of ruthenium(II) and their catalytic activities towards oxidation of alcohols

90-93Mixed ligand ruthenium(II) complexes [Ru(CO)(Y)(L)], where Y = PPh3, AsPh3, pyridine (py) or piperidine (pip) and H2L = Schiff bases derived from the condensation of o-aminophenol, o-aminothiophenol and anthranillic acid with acetyl acetone in 2:1 molar ratio, obtained from the reactions of [RuHX(CO)(EPh3)2(Y)] (X = H or Cl ; E = P or As) with H2L, have been found to show catalytic activity in the oxidation of alcohols to aldehydes

Electrospinning of alumina nanofibers using different precursors

Electrospinning technique is becoming increasingly13; popular for the preparation of nanofibers [1x2013;5]. The13; process involves the application of a strong electrostatic13; field to a capillary connected with a reservoir13; containing a polymer solution or melt. Under the13; influence of the electrostatic field, a pendant droplet of13; the polymer solution at the capillary tip is deformed13; into a conical shape (Taylor cone). If the voltage surpasses13; a threshold value, electrostatic forces overcome13; the surface tension, and a fine charged jet is ejected.13; The jet moves towards a ground plate, which acts as a13; counter electrode. The solvent begins to evaporate13; immediately after the jet is formed. The result is the13; deposition of nanofibers on a substrate located above13; the counter electrode. Initially, this technique was used13; for the preparation of polymer nanofibers [6x2013;9]. In13; recent years; this technique has been used for the13; preparation of metal oxide/ceramic nanofibers such as13; silica, zirconia, titania, nickel oxide, barium titanate,13; lead zirconate titanate and other oxide materials [10x2013;13; 30]. The nanofibers formed could be aligned (parallel13; and cross patterns) when an insulated cylinder attached13; to the axel of a DC motor is used as the substrate [31].13; Xia et al. [32] prepared polymeric and ceramic nanofibers13; as axially aligned arrays by the use of a collector13; consisting of two pieces of electrically conductive13; substrate separated by a gap. Katta et al. used copper13; wires spaced evenly in the form of a circular drum as a13; collector of the electro spun nanofiber

Organonickel complexes encumbering bis-imidazolylidene carbene ligands. Synthesys, X-ray structure and catalytic insights on Buchwald-Hartwig amination reactions

New four coordinated homoleptic bis(diimidazolylidene)nickel(II) complexes (C1 & C2) were synthesized and characterized by elemental analysis, NMR (1H and 13C) as well as ESI-Mass spectrometry. The molecular structure of the complex C1 was identified by means of single-crystal X-ray diffraction analysis, which revealed that the complexes possess a distorted square planar geometry with chelating bis(diimidazolylidene) NHC ligands and two non coordinating bromide counter ions in tetradentate C4 fashion. A survey of their catalytic activity in Buchwald 12Hartwig amination has been performed. The newly synthesized complexes also catalyzed the amination of aryl chlorides in the presence of KOtBu. Various aryl chlorides and amines can react smoothly to give the corresponding aminated products in moderate to high yields. The scope of the reaction encompasses electronically varied aryl chlorides and nitrogen-containing heteroaryl chlorides, including pyridine and quinoline derivatives. Both secondary and primary amines are well tolerated under the optimal reaction conditions