Loading...
Search for:
axial-ligands
0.005 seconds
Study of NxOy Macrocycles Bearing Peripheral Functional Groups as Axial Ligands of Zinc Tetraphenylporphyrin
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
In this project, M2 macrocyclic ligand, bearing three pyridine side arms (3p) was synthesized and characterized by employing elemental analysis and 1H NMR, 13C NMR and IR methods. The interaction of 3p with zinc tetraphenylporphyrin was investigated, using fluorescence and UV-vis spectroscopy in solution phase. The observed quenching in the fluorescence spectrum alongside Q band shift in UV-vis spectrum indicate on the interaction of 3p with ZnTPP. The formation constant for these interactions in 1:1 ratio was calculated 10100 M-1, employing fluorescence method. The formation constant was calculated 630 M-1 for 1:2 ratio for 3p:ZnTPP. Having 1:2 ratio 3pZnTPP was also synthesized and...
Catalytic activity of manganese(III)-oxazoline complexes in urea hydrogen peroxide epoxidation of olefins: The effect of axial ligands
, Article Journal of Molecular Catalysis A: Chemical ; Volume 260, Issue 1-2 , 2006 , Pages 163-169 ; 13811169 (ISSN) ; Latifi, R ; Tahsini, L ; Sharif University of Technology
2006
Abstract
The catalytic activity of two manganese(III)-oxazoline complexes [Mn(phox)2(CH3OH)2]ClO4 and Mn(phox)3 (Hphox = 2-(2′-hydroxylphenyl)oxazoline), was studied in the epoxidation of various olefins. All of epoxidation reactions were carried out in (1:1) mixture of methanol:dichloromethane at room temperature using urea hydrogen peroxide (UHP) as oxidant and imidazole as co-catalyst. The epoxide yields clearly demonstrate the influence of steric and electronic properties of olefins, the catalysts and nitrogenous bases as axial ligand. [Mn(phox)2(CH3OH)2]ClO4 catalyst with low steric properties has higher catalytic activity than Mn(phox)3. The highest epoxide yield (95%) was achieved for indene...
Synthesis and Study of Catalytic Activity of Iron (III)-bis(2-oxazolinyl) Methane complex by Urea Hydrogen Peroxide in Oxidation of Sulfides
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
Considerable effort has been directed in recent years towards the transition metal complex catalyzed oxidation of organic compounds. Herein the synthsis of the iron complex of bis(oxazoline) ligand as a novel catalyst is reported, and the catalytic activity of this complex in oxidation of sulfides is investigated. Bis(2-oxazolynil)methane as ligand is prepared by condensation of diethylmalonate with 2-aminoethanole in 1:2 molar ratio and finally corresponding complex is synthesized by the reaction between FeCl3.6H2O and Bis(2-Oxazolynil)methane in 1:1 molar ratio. The complex is characterized by using IR, UV-Vis, cyclic voltametery, conductometery and elemental analysis data. Moreover,...
Catalytic oxidation of sulfides to sulfoxide using manganese(III) complexes with bidentate O,N-donor oxazoline ligand and UHP oxidizing agent
, Article Catalysis Communications ; Volume 10, Issue 2 , 2008 , Pages 196-200 ; 15667367 (ISSN) ; Latifi, R ; Tahsini, L ; Amini, M ; Sharif University of Technology
2008
Abstract
The efficient catalytic systems were investigated for the oxidation of various sulfide by manganese(III)-oxazoline complexes, [Mn(phox)2(MeOH)2]ClO4 and Mn(phox)3 (Hphox = 2-(2′-hydroxyphenyl)oxazoline). These complexes were found efficient catalysts for the oxidation of sulfides with urea hydrogen peroxide (UHP) in short reaction times (5 min) and under mild condition. Sulfoxides were obtained as the main products together with variable amounts of sulfones. The efficiency of the catalytic system was strongly influenced by the nature of solvents and axial ligands so the best yields were achieved in a mixture of methanol: dichloromethane and in the presence of imidazole as co-catalyst. © 2008...
Synthesis, Structure and Catalytic Application of Mn, Fe and Mo Complexes with Schiff base Ligands in the Oxidation of Olefins and Sulfides and Theoretical Mechanistic Studies on the Catalytic Activity of non-Heme Iron and Copper Enzymes
, Ph.D. Dissertation Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)Synthesis, Structure and Catalytic Application of Mn, Fe and Mo Complexes with Schiff base and Oxazoline ligands and Theoretical Mechanistic Studies on the Role of Heme and non-Heme Iron(IV)-Oxo Species in Hydroxylation and Epoxidation Reactions
, Ph.D. Dissertation Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
The first part of this thesis describes the synthesis and characterization of several Mn, Fe and Mo complexes containing tridentate Schiff base and oxazoline ligands and their reactivities as catalysts in the oxidation of organic compounds like olefins and sulfides, as well. The crystal structures of newly prepared cis-dioxo-bis[2-(2′-hydroxyphenyl)-oxazolinato]molybdenum(VI), cis-[MoO2(phox)2] and (N-hydroxyphenyl-salicylidenamine)(acetylacetonato)ethanol iron(III), [FeIII(N-OPh-sal)(acac)EtOH] complexes have been described by X-ray crystallography. Due to the difficulties in the preparation of suitable single crystals of novel...
How does the axial ligand of cytochrome p450 biomimetics influence the regioselectivity of aliphatic versus aromatic hydroxylation?
, Article Chemistry - A European Journal ; Volume 15, Issue 22 , 2009 , Pages 5577-5587 ; 09476539 (ISSN) ; Tahsini, L ; Nam, W ; Sharif University of Technology
2009
Abstract
The catalytic activity of highvalent iron-oxo active species of heme enzymes is known to be dependent on the nature of the axial ligand trans to the iron-oxo group. In a similar fashion, experimental studies on iron-oxo porphyrin biomimetic systems have shown a significant axial ligand effect on ethylbenzene hydroxylation, with an axial acetonitrile ligand leading to phenyl hydroxylation products and an axial chloride anion giving predominantly benzyl hydroxylation products. To elucidate the fundamental factors that distinguish this regioselectivity reversal in iron-oxo porphyrin catalysis, we have performed a series of density functional theory calculations on the hydroxylation of...