A5058649542- Metal-Catalyzed Oxygenation Mechanisms
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Metal complexes synthesis and properties
- Porphyrin and Phthalocyanine Chemistry
- Oxidative Organic Chemistry Reactions
- CO2 Reduction Techniques and Catalysts
- Magnetism in coordination complexes
- Crystallography and molecular interactions
- Catalysis and Oxidation Reactions
- Photosynthetic Processes and Mechanisms
- Asymmetric Hydrogenation and Catalysis
- Metal-Organic Frameworks: Synthesis and Applications
- Synthesis and Characterization of Heterocyclic Compounds
- Catalytic Processes in Materials Science
- Inorganic and Organometallic Chemistry
- Lanthanide and Transition Metal Complexes
- Catalysts for Methane Reforming
- Synthesis and Biological Evaluation
- Metalloenzymes and iron-sulfur proteins
- Organometallic Complex Synthesis and Catalysis
- Microbial metabolism and enzyme function
- Advanced Photocatalysis Techniques
- Carbon dioxide utilization in catalysis
- Photodynamic Therapy Research Studies
National Institute of Technology Calicut
2018-2025
Ewha Womans University
2015-2024
Ewha Womans University Medical Center
2015-2019
Seoul Institute
2017-2019
Bharathidasan University
2010-2017
A mononuclear non-heme manganese(V)-oxo complex, [Mn(V)(O)(TAML)](-) (1), was synthesized by activating dioxygen in the presence of olefins with weak allylic C-H bonds and characterized structurally spectroscopically. In mechanistic studies, formation rate 1 found to depend on bond dissociation energies (BDEs) olefins, a kinetic isotope effect (KIE) value 16 obtained reactions cyclohexene cyclohexene-d10. These results suggest that hydrogen atom abstraction from putative Mn(IV)-superoxo...
Mononuclear nonheme manganese(IV)-oxo complexes binding calcium ion and other redox-inactive metal ions, [(dpaq)MnIV(O)]+-M n+ (1-Mn+, M = Ca2+, Mg2+, Zn2+, Lu3+, Y3+, Al3+, Sc3+) (dpaq 2-[bis(pyridin-2-ylmethyl)]amino- N-quinolin-8-yl-acetamidate), were synthesized by reacting a hydroxomanganese(III) complex, [(dpaq)MnIII(OH)]+, with iodosylbenzene (PhIO) in the presence of ions (M n+). The Mn(IV)-oxo characterized using various spectroscopic techniques. In reactivity studies, we observed...
A new family of nickel(II) complexes the type [Ni(L)(CH(3)CN)](BPh(4))(2), where L=N-methyl-N,N',N'-tris(pyrid-2-ylmethyl)-ethylenediamine (L1, 1), N-benzyl-N,N',N'-tris(pyrid-2-yl-methyl)-ethylenediamine (L2, 2), N-methyl-N,N'-bis(pyrid-2-ylmethyl)-N'-(6-methyl-pyrid-2-yl-methyl)-ethylenediamine (L3, 3), N-methyl-N,N'-bis(pyrid-2-ylmethyl)-N'-(quinolin-2-ylmethyl)-ethylenediamine (L4, 4), and N-methyl-N,N'-bis(pyrid-2-ylmethyl)-N'-imidazole-2-ylmethyl)-ethylenediamine (L5, 5), has been...
Global warming due to the unrestricted release of CO<sub>2</sub> into atmosphere is a prevalent challenge faced by 21<sup>st</sup> century.
Researchers have always been intrigued by one-step selective hydroxylation of aromatic compounds since achieving adequate selectivity toward the target product and avoiding overoxidation are challenging. However, naturally available oxygenase enzymes efficiently selectively perform such transformations under normal atmospheric conditions. Inspired occurring enzymes, researchers undertaken numerous attempts to catalyze oxidation arenes using homogeneous heterogeneous catalysts. In this...
An iron complex with a tetraamido macrocyclic ligand, [(TAML)FeIII]-, was found to be an efficient and selective catalyst for allylic oxidation of cyclohexene by dioxygen (O2); cyclohex-2-enone obtained as the major product along oxide minor product. iron(V)-oxo complex, [(TAML)FeV(O)]-, which formed activating O2 in presence cyclohexene, initiated autoxidation produce cyclohexenyl hydroperoxide, reacted [(TAML)FeIII]- [(TAML)FeV(O)]- autocatalysis. Then, rapidly μ-oxo dimer,...
A manganese(<sc>iii</sc>)–peroxo complex was synthesized by activating dioxygen (O<sub>2</sub>) and the amphoteric reactivity of a manganese(<sc>iii</sc>)–hydroperoxo demonstrated in electrophilic nucleophilic reactions.
Abstract A mononuclear nonheme manganese(IV)–oxo complex binding the Ce 4+ ion, [(dpaq)Mn IV (O)] + –Ce ( 1 ‐Ce ), was synthesized by reacting III (OH)] 2 ) with cerium ammonium nitrate (CAN). characterized using various spectroscopic techniques, such as UV/Vis, EPR, CSI‐MS, resonance Raman, XANES, and EXAFS, showing an Mn−O bond distance of 1.69 Å a Raman band at 675 cm −1 . Electron‐transfer oxygen atom transfer reactivities were found to be greater than those Mn (O) intermediates...
A mononuclear non-heme Mn(III)–aqua complex, [(dpaq)MnIII(OH2)]2+ (1, dpaq = 2-[bis(pyridin-2-ylmethyl)]amino-N-quinolin-8-yl-acetamidate), is capable of conducting hydrogen atom transfer (HAT) reactions much more efficiently than the corresponding Mn(III)–hydroxo [(dpaq)MnIII(OH)]+ (2); high reactivity 1 results from positive one-electron reduction potential (Ered vs SCE 1.03 V), compared to that 2 −0.1 V). The HAT mechanism varies between electron followed by proton and one-step concerted...
The reaction of Li[(TAML)CoIII]·3H2O (TAML = tetraamido macrocyclic tetraanionic ligand) with iodosylbenzene at 253 K in acetone the presence redox-innocent metal ions (Sc(OTf)3 and Y(OTf)3) or triflic acid affords a blue species 1, which is converted reversibly to green 2 upon cooling 193 K. electronic structures 1 have been determined by combining advanced spectroscopic techniques (X-band electron paramagnetic resonance (EPR), nuclear double (ENDOR), X-ray absorption spectroscopy/extended...
The iron(III) complexes of the bis(phenolate) ligands 1,4-bis(2-hydroxy-4-methyl-benzyl)-1,4-diazepane H2(L1), 1,4-bis(2-hydroxy-4-nitrobenzyl)-1,4-diazepane H2(L2), 1,4-bis(2-hydroxy-3,5-dimethylbenzyl)-1,4-diazepane H2(L3) and 1,4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)-1,4-diazepane H2(L4) have been isolated studied as structural functional models for 3,4-PCD enzymes. [Fe(L1)Cl] 1, [Fe(L2)(H2O)Cl] 2, [Fe(L3)Cl] 3 [Fe(L4)Cl] 4 characterized using ESI-MS, elemental analysis, absorption...
A series of Ni(ii) complexes the types [Ni(L)(CH3CN)2](BPh4)21-3, 5 and [Ni(L4)](BPh4)24, where L = N,N'-bis(2-pyrid-2-ylmethyl)-1,4-diazepane (L1), N-(6-methylpyrid-2-ylmethyl)-N'-(pyrid-2-ylmethyl)-1,4-diazepane (L2), N,N'-bis(6-methyl-2-pyridylmethyl)-1,4-diazepane (L3), N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)ethylenediamine (L5) L4 N,N'-bis((1-methyl-1H-imidazole-2-yl)methyl)-1,4-diazepane, have been isolated characterized. The complex cations 1 4 possess, respectively, distorted...
Copper( ii ) complexes of tridentate (N 2 O) Schiff base ligands as efficient catalysts for 2-aminophenol oxidation to 2-aminophenoxazin-3-one with excellent reaction rates.
A carbazolyl appended trans-pyridyl porphyrin (1) was synthesized and its dicationic form 2 obtained by methylation of the pyridyl group. Copper zinc complexes (Cu(II), 3; Zn(II), 4) were isolated characterized various modern spectroscopic techniques. The DNA binding properties 2, 3, 4 have been explored against calf thymus-DNA (CT-DNA). quantized using intrinsic constant (Kb) that calculated UV-visible absorption spectroscopy, value Kb = 1.6 × 106 M-1 for compound reveals a better...
Selective oxidation of aromatic substrates to phenols is a challenging goal in synthetic chemistry. Herein, we investigate the catalytic activity nickel(II) complexes type [Ni(L)(CH3CN)](X)2 (1‐4); (X = ClO4‐, BPh4‐, L N4Py, BnTPEN and, BnImDPEN) supported by pentadentate ligands hydroxylation corresponding using H2O2. In benzene oxidation, complex 2 showed phenol yield 28% and turnover number 560 with 99% selectivity. Also, preferential C‐H bonds over aliphatic was noted during substituted...
Activation of CO2 and conversion into value-added products is an effective option to mitigate emission. The nickel(II) complexes [Ni(L1)](ClO4)2 1, [Ni(L2)](ClO4)2 2, [Ni(L3)(CH3CN)2](Ph4B)2 3 diazepane-based ligands [1,4-bis[(pyridin-2-yl-methyl)]-1,4-diazepane (L1), 1,4-bis[2-(pyridin-2-yl)ethyl]-1,4-diazepane (L2), 4-bis[2-(quinoline-2-yl)-methyl]-1,4-diazepane (L3)] have been synthesized structurally characterized. were employed as the catalysts for atmospheric organic carbonates in...
Abstract Streamline synthesis of cyclic alcohols has been an enduring goal in synthetic chemistry. In this regard, a series aminoquinoline‐based pincer ligands (L1(H)=2‐(dimethylamino)‐ N ‐(quinolin‐8‐yl)acetamide, L2(H)=2‐(diethylamino)‐ ‐(quinoline‐8‐yl)acetamide, L3(H)=2‐(dipropylamino)‐ ‐(quinoline‐8‐yl)acetamide and L4(H)=2‐(dibutylamino)‐ ‐(quinolin‐8‐yl)acetamide)) corresponding nickel(II) complexes the type [Ni(L)Cl] ( 1–4 ) were synthesized characterized using modern analytical...