433940-66-0Relevant academic research and scientific papers
Ruthenium(II) unsymmetrical N2O2 tetradentate Schiff-base complexes: Synthesis, characterization, and catalytic studies
Gowri,Muthukumar,Krishnaraj,Viswanathamurthi,Prabhakaran,Natarajan
, p. 524 - 533 (2010)
A series of six-coordinate ruthenium(II) complexes [Ru(CO)(Lx)(B)] (B= PPh3, AsPh3 or Py; Lx = unsymmetrical tetradentate Schiff base, x= 5-8; L5=salen-2-hyna, L6=Cl-salen-2-hyna, L7=valen-2-hyna, L8=o-hyac-2-hyna) have been prepared by reacting [RuHCl(CO) (EPh3)2(B)] (E=P or As) with unsymmetrical Schiff bases in benzene under reflux. The new complexes have been characterized by analytical and spectroscopic (infrared, electronic, 1H, 31P, and 13C NMR) data. An octahedral structure has been assigned for all the complexes. The new complexes are efficient catalysts for the transfer hydrogenation of ketones and also exhibit catalytic activity for the carbon-carbon coupling reactions.
Double end-on azido derivative of a tridentate (NNO) Schiff base dimeric copper(II) complex: synthesis, X-ray structure, magnetic property and catalytic effectiveness
Chowdhury, Habibar,Bera, Rajesh,Rizzoli, Corrado,Adhikary, Chandan
, p. 3062 - 3078 (2020/10/29)
A dimeric copper(II) complex, bis{(2-[1-(aminoethylimino)ethyl]-phenoxo}-di-μ1,1-azido-dicopper(II), [Cu2(L)2(μ2-1,1-N3)2] (1) [L = 2-[1-(aminoethylimino)ethyl]-phenoxo ion], has been isolated using a self-assembly reaction using a 1:1:1 molar ratio of Cu(NO3)2·3H2O, HL and NaN3 in methanol at room temperature and characterized through X-ray diffraction analysis and spectroscopic studies. X-ray structural analysis reveals that 1 consists of two distinct dinuclear molecular units, where each copper(II) center in the individual dinuclear unit adopts a distorted square pyramidal geometry with a CuN4O chromophore ligated through a tridentate (NNO) Schiff base and two N atoms of two different bridging azides in μ1,1-mode. Two Cu(II) centers are linked through double μ2-1,1-N3 bridges to form the dinuclear unit [Cu2(L)2(μ2-1,1-N3)2]. In the crystalline state, the dinuclear units in 1 are associated through weak intermolecular N-H?O hydrogen bonds to afford a 2-D sheet structure viewed along the crystallographic a-axis. The small magnitude of the antiferromagnetic interaction (J = –0.45 cm?1) is a result of the long Cu···Cu separation (3.205(2) ?). The catalytic efficacy of 1 was studied in a series of solvents for the epoxidation of alkenes using tert-butyl-hydroperoxide (TBHP) as an efficient oxidant under mild conditions.
Hydrogenation of alkenes and alkynes catalysed by N?O (imino)phenol palladium(II) complexes: Structural, kinetics and chemoselectivity studies
Tshabalala, Thandeka A.,Ojwach, Stephen O.
, p. 35 - 42 (2018/08/21)
Reactions of 2-(2-methoxyethylimino)ethyl)phenol (HL1), 2-(2-hydroxyethylimino)ethyl)phenol (HL2), 2-(2-aminoethylimino)ethyl)phenol (HL3) and 2-(2-hydroxyethylimino)methyl)phenol (HL4) with [PdCl2(COD)] afforded the neutral palladium complexes [PdCl2(HL1)] (1), [PdCl2(HL2)] (2), [PdCl2(HL3)] (3), [PdCl2(HL4)] (4) respectively. Treatment of complex 1 with PPh3 gave the cationic complex [Pd(HL1)ClPPh3]+ (5), while reactions of 4 with Pd(OAc)2, in the presence of PPh3 and p-TsOH produced the corresponding palladium complex, [Pd(L1) (OTs) (PPh3)] (6). The molecular structure of 4a (derivative of 4) contained two bidentate anionic ligands (L4). Complexes 1–6 formed active catalysts in hydrogenation of alkenes and alkynes, in which the catalytic activities were largely dependent on the pendant donor atom of the ligand motif. Isomerization reactions were dominant in terminal alkenes hydrogenation reactions, while hydrogenation of alkynes to alkanes occurred in two steps via alkene intermediates. Kinetics data were consistent with homogeneous active species. Density functional theory studies supported the hemi-labile nature of the ligands, and offered insights into the catalytic activity trends observed.
