A5102798932- Metal-Catalyzed Oxygenation Mechanisms
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Nitric Oxide and Endothelin Effects
- Metalloenzymes and iron-sulfur proteins
- Advanced biosensing and bioanalysis techniques
- Metal complexes synthesis and properties
- DNA and Biological Computing
- Photosynthetic Processes and Mechanisms
- Porphyrin and Phthalocyanine Chemistry
- Hemoglobin structure and function
- Psychosocial Factors Impacting Youth
- Sulfur Compounds in Biology
- Diverse Approaches in Healthcare and Education Studies
- Education and Learning Interventions
- Ammonia Synthesis and Nitrogen Reduction
- Ferrocene Chemistry and Applications
- Lanthanide and Transition Metal Complexes
- Healthcare Education and Workforce Issues
- Crystallography and molecular interactions
- Photoreceptor and optogenetics research
- Magnetism in coordination complexes
- Educational Systems and Policies
- Educational Research and Pedagogy
- Inorganic Fluorides and Related Compounds
University of Massachusetts Boston
2024
Boston University
2024
Brown University
2014-2024
John Brown University
2014-2023
Ajou University
2017-2022
Providence College
2013-2021
Inha University
2020
Stony Brook University
2012
Seoul National University
2011
Kyungpook National University
2009
A magnetic personality: Commercially available Fe3O4 nanoparticles were utilized for efficient nitroarene reductions, and could be recycled up to 10 times using separation, whilst retaining activity (99 % aniline yield in each case without any side-products). Excellent chemoselectivity reduction of the nitro versus other functional groups, such as halogen, ester, O-benzyl, N-Cbz was observed. Detailed facts importance specialist readers are published "Supporting Information". Such documents...
ConspectusNitric oxide (NO) is an important signaling molecule that involved in many physiological and pathological functions. Iron–sulfur proteins are one of the main reaction targets for NO, [Fe–S] clusters within these converted to various iron nitrosyl species upon with which dinitrosyl complexes (DNICs) most prevalent. Much progress has been made identifying origin cellular DNIC generation. However, it not well-understood other products besides DNICs may form during cluster degradation...
Multicomponent reactions enable the synthesis of large molecular libraries from relatively few inputs. This scalability has led to broad adoption these by pharmaceutical industry. Here, we employ four-component Ugi reaction demonstrate that multicomponent can provide a basis for large-scale data storage. Using this combinatorial chemistry encode more than 1.8 million bits art historical images, including Cubist drawing Picasso. Digital is written using robotically synthesized products, and...
Cellular dinitrosyl iron complexes (DNICs) have long been considered NO carriers. Although other physiological roles of DNICs postulated, their chemical functionality outside transfer has not demonstrated thus far. Here we report the unprecedented dioxygen reactivity a N-bound {Fe(NO)2}10 DNIC, [Fe(TMEDA)(NO)2] (1). In presence O2, 1 becomes nitrating agent that converts 2,4,-di-tert-butylphenol to 2,4-di-tert-butyl-6-nitrophenol via formation putative iron-peroxynitrite...
Dinitrosyl iron complexes (DNICs) are among the most abundant NO-derived cellular species. Monomeric DNICs can exist in {Fe(NO)2}9 or {Fe(NO)2}10 oxidation state (in Enemark–Feltham notation). However, experimental studies of analogous both states rare, which prevents a thorough understanding differences electronic structures these Here, DNIC [Fe(dmp)(NO)2](OTf) (1; dmp = 2,9-dimethyl-1,10-phenanthroline) is synthesized from ferrous precursor via an unusual pathway, involving...
Copper(I)−dioxygen adducts are important in biological and industrial processes. For the first time we explore relationship between ligand electronics, CuI−O2 adduct formation exogenous substrate reactivity. The copper(I) complexes [CuI(R-MePY2)]+ (1R, where R = Cl, H, MeO, Me2N) were prepared; R-MePY2 4-pyridyl substituted bis[2-(2-pyridyl)ethyl]methylamine chelates. Both redox potential of 1R (ranging from E1/2 −270 mV for 1Cl to −440 1MeN vs FeCp2/FeCp2+) νCO CO 2093 cm-1 1Cl-CO 2075...
The O 2 -reaction chemistry of 1:1 mixtures (F 8 )Fe II (1; F = tetrakis(2,6-diflurorophenyl)porphyrinate) and [(L Me N )Cu I ] + (2; L , -bis{2-[2-( ′, ′-4-dimethylamino)pyridyl]ethyl}methylamine) is described, to model aspects the occurring in cytochrome c oxidase. Spectroscopic investigations, along with stopped-flow kinetics, reveal that low-temperature oxygenation 1/2 leads rapid formation a heme-superoxo species III -(O \documentclass[12pt]{minimal} \usepackage{amsmath}...
Copper(I)−acetonitrile complexes are exceedingly useful starting materials for the synthesis of copper(I) with polydentate ligands. To extend utility such chemistry to solution studies in relatively low-dielectric solvents (i.e., diethyl ether, toluene) and aid obtaining products amenable X-ray diffraction studies, we have recently begun employ counteranions as B(C6F5)4- bioinorganic studies. Thus, [Cu(MeCN)4]B(C6F5)4 (1) is presented. Its recrystallization from CH2Cl2/pentane yields linear,...
The reduction of nitrate (NO3–) to nitrite (NO2–) is significant biological and environmental importance. While MoIV(O) MoVI(O)2 complexes that mimic the active site structure reducing enzymes are prevalent, few these model can reduce through oxygen atom transfer (OAT) chemistry. We present a novel strategy induce chemistry previously known catalyst MoIV(O)(SN)2 (2), where SN = bis(4-tert-butylphenyl)-2-pyridylmethanethiolate, otherwise incapable achieving OAT with nitrate. Addition Lewis...
Abstract Acid-base reactions are ubiquitous, easy to prepare, and execute without sophisticated equipment. Acids bases also inherently complementary naturally map a universal representation of “0” “1.” Here, we propose how leverage acids, bases, their encode binary information perform processing based upon the majority negation operations. These operations form functionally complete set that use implement more complex computations such as digital circuits neural networks. We present building...
A mixed-valent Cu(I)Cu(II) complex, [CuI,II2(UN-O-)]2+ (1), reacts with NO(g) at -80 °C to form [CuI,II2(UN-O-)(NO)]2+ (2), best described as a nitrosyl complex that has ν(N-O) band 1670 cm-1 in its infrared (IR) spectrum. Complex 2 undertakes one-electron oxidation via the addition of O2(g) generate new intermediate, superoxide and adduct, [CuII2(UN-O-)(NO)(O2-)]2+ (3), based on distinctively blue-shifted 1853 cm-1. Over course 20 min °C, 3 is converted peroxynitrite (PN)...
Molecular data systems have the potential to store information at dramatically higher density than existing electronic media. Some of first experimental demonstrations this idea used DNA, but nature also uses a wide diversity smaller non-polymeric molecules preserve, process, and transmit information. In paper, we present general framework for quantifying chemical memory, which is not limited polymers extends mixtures all types. We show that theoretical limit molecular two orders magnitude...
Catalytic reduction of O2 to H2O, and coupling membrane proton translocation, occurs at the heterobinuclear heme a3-CuB active site cytochrome c oxidase. One CuB ligated histidines is cross-linked a neighboring tyrosine (C-N bond; C6 histidine epsilon-nitrogen), protic residue this His-Tyr moiety proposed participate as both an electron donor in catalytic dioxygen event. To provide insight into chemistry such moiety, we have synthesized characterized tetra- tridentate pyridylalkylamine...
Recent spectroscopic, kinetics, and structural studies on cytochrome c oxidases (CcOs) suggest that the histidine−tyrosine cross-link at heme a3−CuB binuclear active site plays a key role in reductive O2-cleavage process. In this report, we describe dioxygen reactivity of copper heme/Cu assemblies which imidazole−phenol moieties are employed as part ligand LN4OH (2-{4-[2-(bis-pyridin-2-ylmethyl-amino)-ethyl]-imidazol-1-yl}-4,6-di -tert-butyl-phenol). Stopped-flow kinetic reveal...
The appropriate control of redox and coordination chemistry dinitrosyl iron complexes enables them to become anti-inflammatory agents.
The crosstalk between two biologically important signaling molecules, nitric oxide (NO) and hydrogen sulfide (H2S), proceeds via elusive mechanism(s). Herein we report the formation of H2S by action NO on synthetic [2Fe-2S] clusters when reaction environment is capable providing a formal H• (e–/H+). Nitrosylation (NEt4)2[Fe2S2(SPh)4] (1) in presence PhSH or tBu3PhOH results (NEt4)[Fe(NO)2(SPh)2] (2) with concomitant generation PhSSPh tBu3PhO•. amount generated dependent electronic cluster as...
Heme-Cu/O2 adducts are of interest in the elucidation fundamental metal-O2 chemistry occurring heme-Cu enzymes which effect reductive O-O cleavage dioxygen to water. In this report, four heme-peroxo-copper [FeIII-(O22-)-CuII]+ complexes (1-4), varying their ligand architecture, copper-ligand denticity, or both and thus structures physical properties compared reactivity toward CO, PPh3, acids, cobaltocene, phenols. 1 2, copper(II) is N4-tetradentate, peroxo unit bound side-on iron(III) end-on...
New types of degradation products iron-sulfur clusters by nitric oxide (NO) have been identified in the acidic environment. In absence acid, NO reacts with (Et(4)N)(2)[Fe(2)S(2)Cl(4)] (1) to form a {Fe(NO)(2)}(9) dinitrosyliron complex, (Et(4)N)[Fe(NO)(2)Cl(2)] (2), wherein bridging sulfides are oxidized elemental sulfur four electrons (2S(2-) → 2S(0) + 4e(-)). contrast, successive additions and HCl 1 result formation {Fe(NO)}(7) mononitrosyliron (Et(4)N)[Fe(NO)Cl(3)] (3), along hydrogen...
A new {Fe(NO)2}10 dinitrosyl iron complex possessing a 2,9-dimethyl-1,10-phenanthroline ligand has been prepared. This exhibits dioxygenase activity, converting NO to nitrate (NO3−) anions. During the oxygenation reaction, formation of reactive nitrating species is implicated, as shown in effective o-nitration with phenolic substrate.
Reversible modification of iron-sulfur clusters by nitric oxide acts as a genetic switch in group regulatory proteins. While the conversion [Fe-S] to iron-nitrosyls has been widely studied past, little is known about reverse process, repair clusters. Reported here system which mononitrosyl iron complex (MNIC), (PPN)[Fe(StBu)3(NO)] (1), converted [2Fe-2S] cluster, (PPN)2[Fe2S2(SCH2CH2C(O)OMe)4] (2). This requires only addition cysteine analogue, 3-mercaptomethylpropionate (MMP), at room...