A5007210590- Metal complexes synthesis and properties
- Magnetism in coordination complexes
- Metalloenzymes and iron-sulfur proteins
- Organometallic Complex Synthesis and Catalysis
- Metal-Catalyzed Oxygenation Mechanisms
- Organometallic Compounds Synthesis and Characterization
- Inorganic and Organometallic Chemistry
- Crystal structures of chemical compounds
- Inorganic Chemistry and Materials
- Metal-Organic Frameworks: Synthesis and Applications
- Porphyrin and Phthalocyanine Chemistry
- Lanthanide and Transition Metal Complexes
- Synthesis and characterization of novel inorganic/organometallic compounds
- Electron Spin Resonance Studies
- Crystal Structures and Properties
- Hemoglobin structure and function
- Photosynthetic Processes and Mechanisms
- Polyoxometalates: Synthesis and Applications
- Coordination Chemistry and Organometallics
- Electrocatalysts for Energy Conversion
- DNA and Nucleic Acid Chemistry
- Esophageal and GI Pathology
- Catalysis and Oxidation Reactions
- Chemical Reaction Mechanisms
- Trace Elements in Health
Stellenbosch University
2020-2023
University of Pretoria
2017-2023
University of Limpopo
2020-2021
University of Notre Dame
2021
South African Reserve Bank
2017-2020
Observatoire des Sciences de l’Univers Terre Homme Environnement Temps Astronomie
2009-2019
University of Regensburg
2017
Schott (Germany)
2017
Friedrich Schiller University Jena
2017
Physiologie de la Nutrition et du Comportement Alimentaire
2017
Forty-six patients with severe nonpenetrating brain injury [Glasgow Coma Scale (GCS) 4–7] were randomized to standard management at 37°C (n = 22) and systemic hypothermia 32 33°C 24). The two groups balanced in terms of age (Wilcoxon's rank sum test, p > 0.95), randomizing GCS (chi-square 0.54), primary diagnosis. Cooling was begun within 6 h by use cooling blankets. Metocurine morphine given hourly during induction maintenance hypothermia. Rewarming a rate 1°C per 4 beginning 48 after...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAxial ligation modes in iron(III) porphyrins. Models for the oxidized reaction states of cytochrome P-450 enzymes and molecular structure protoporphyrin IX dimethyl ester p-nitrobenzenethiolateS. C. Tang, S. Koch, G. Papaefthymiou, Foner, R. B. Frankel, James A. Ibers, H. HolmCite this: J. Am. Chem. Soc. 1976, 98, 9, 2414–2434Publication Date (Print):April 1, 1976Publication History Published online1 May 2002Published inissue 1 April...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTrigonal-planar [M(SR)3]1- complexes of cadmium and mercury. Structural similarities between mercury-cysteine cadmium-cysteine coordination centersEric S. Gruff Stephen A. KochCite this: J. Am. Chem. Soc. 1990, 112, 3, 1245–1247Publication Date (Print):January 1, 1990Publication History Published online1 May 2002Published inissue 1 January 1990https://pubs.acs.org/doi/10.1021/ja00159a054https://doi.org/10.1021/ja00159a054research-articleACS...
X-ray absorption fine structure (XAFS) spectra have been measured for a series of structurally characterized zinc model complexes that mimic the sites found in metalloproteins. These include both inorganic coordination and small binding peptides. data analyzed to determine extent which Zn XAFS can be used reliably ligation environment zinc. Because Zn−N Zn−S oscillations are nearly out phase over accessible energy range, it is difficult relative number sulfur nitrogen scatterers, some cases,...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolid-state mercury-199 and cadmium-113 NMR studies of mercury- cadmium-thiolate complexes. Spectroscopic models for [Hg(SCys)n] centers in the bacterial mercury resistance proteinsRodolfo A. Santos, Eric S. Gruff, Stephen Koch, Gerard HarbisonCite this: J. Am. Chem. Soc. 1991, 113, 2, 469–475Publication Date (Print):January 1, 1991Publication History Published online1 May 2002Published inissue 1 January...
In Brief Somatosensory evoked potential (SSEP) monitoring is used to prevent nerve damage in spine surgery and detect changes upper extremity function. Upper SSEP conduction may indicate impending injury. We investigated the effect of operative positioning on function retrospectively 1000 consecutive surgeries that monitoring. The vast majority (92%) were reversed by modifying arm position therefore classified as position-related. incidence position-related was calculated compared for five...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSingle-crystal spectral studies of Fe(SR)4- [R = 2,3,5,6,-(Me)4C6H]: the electronic structure ferric tetrathiolate active siteMatthew S. Gebhard, Joseph C. Deaton, Stephen A. Koch, Michelle Millar, and Edward I. SolomonCite this: J. Am. Chem. Soc. 1990, 112, 6, 2217–2231Publication Date (Print):March 1, 1990Publication History Published online1 May 2002Published inissue 1 March...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structures of Zn(SR)2 complexes: structural models for the proposed [Zn(cys-S)2(his)2] center in transcription factor IIIA and related nucleic acid binding proteinsDouglas T. Corwin Jr. Stephen A. KochCite this: Inorg. Chem. 1988, 27, 3, 493–496Publication Date (Print):February 1, 1988Publication History Published online1 May 2002Published inissue 1 February...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFerric porphyrin thiolates. Possible relation to cytochrome P-450 enzymes and the structure of (p-nitrobenzenethiolato)iron(III) protoporphyrin IX dimethylesterStephen Koch, S. Conrad Tang, R. H. Holm, Richard B. Frankel, James A. IbersCite this: J. Am. Chem. Soc. 1975, 97, 4, 916–918Publication Date (Print):February 1, 1975Publication History Published online1 May 2002Published inissue 1 February 1975https://doi.org/10.1021/ja00837a052Request...
Sn3S7·(NMe4)2·H2O has been shown to consist of the framework composition [Sn3S7]2– with two exchangeable [NMe4]+ ions occupying cavities in structure; these molecules can be exchanged a variety alkali, alkali earth and transition metal cations.
Reactions of NO and CO with Fe(II) complexes the tripodal trithiolate ligands NS3 PS3* yield trigonal-bipyramidal (TBP) varying redox states reactivity patterns respect to dissociation diatomic ligand. The previously reported four-coordinate [Fe(II)(NS3)](-) complex reacts irreversibly gas S = 3/2 {FeNO}(7) [Fe(NS3)(NO)](-) anion, isolated as Me(4)N(+) salt. In contrast, reaction species generated by FeCl(2) Li(3)PS3* gives a high neutral, TBP, 1 complex, [Fe(PS3*)(NO)], first example...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis, structure, and interconversion of polypyrazolylborate complexes molybdenum(V)Sandra Lincoln Stephen A. KochCite this: Inorg. Chem. 1986, 25, 10, 1594–1602Publication Date (Print):May 1, 1986Publication History Published online1 May 2002Published inissue 1 1986https://pubs.acs.org/doi/10.1021/ic00230a017https://doi.org/10.1021/ic00230a017research-articleACS PublicationsRequest reuse permissionsArticle Views266Altmetric-Citations70LEARN...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthetic approaches to 14-, 15-, and 16-membered tetraaza macrocycles their metal complexesS. C. Tang, S. Koch, G. N. Weinstein, R. W. Lane, H. HolmCite this: Inorg. Chem. 1973, 12, 11, 2589–2595Publication Date (Print):November 1, 1973Publication History Published online1 May 2002Published inissue 1 November 1973https://pubs.acs.org/doi/10.1021/ic50129a020https://doi.org/10.1021/ic50129a020research-articleACS PublicationsRequest reuse...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTNickel(II) Thiolate Complex with Carbon Monoxide and Its Fe(II) Analog: Synthetic Models for CO Adducts of Nickel−Iron-Containing EnzymesDao Hinh Nguyen, Hua-Fen Hsu, Michelle Millar, Stephen A. Koch, Catalina Achim, Emile L. Bominaar, Eckard MünckView Author Information Department Chemistry State University New York at Stony Brook Brook, 11794-3400 Carnegie Mellon Pittsburgh, Pennsylvania 15213 Cite this: J. Am. Chem. Soc. 1996, 118, 37,...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTChemistry of Iron Thiolate Complexes with CN- and CO. Models for the [Fe(CO)(CN)2] Structural Unit in Ni−Fe Hydrogenase EnzymesHua-Fen Hsu, Stephen A. Koch, Codrina V. Popescu, Eckard MünckView Author Information Department Chemistry State University New York at Stony Brook Brook, 11794-3400 Chemistry, Carnegie Mellon Pittsburgh, Pennsylvania 15213 Cite this: J. Am. Chem. Soc. 1997, 119, 35, 8371–8372Publication Date (Web):September 3,...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGeneral synthesis of iron(III) tetrathiolate complexes. Structural and spectroscopic models for the [Fe(Cys-S)4] center in oxidized rubredoxinLynn E. Maelia, Michelle Millar, Stephen A. KochCite this: Inorg. Chem. 1992, 31, 22, 4594–4600Publication Date (Print):October 1, 1992Publication History Published online1 May 2002Published inissue 1 October...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSingle-crystal spectroscopic studies of Fe(SR)42- (R = 2-(Ph)C6H4): electronic structure the ferrous site in rubredoxinMatthew S. Gebhard, Stephen A. Koch, Michelle Millar, Frank J. Devlin, Philip Stephens, and Edward I. SolomonCite this: Am. Chem. Soc. 1991, 113, 5, 1640–1649Publication Date (Print):February 1, 1991Publication History Published online1 May 2002Published inissue 1 February...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTrigonal planar [Zn(SR)3]1- complex. A possible new coordination mode for zinc-cysteine centersEric S. Gruff and Stephen A. KochCite this: J. Am. Chem. Soc. 1989, 111, 23, 8762–8763Publication Date (Print):November 1, 1989Publication History Published online1 May 2002Published inissue 1 November 1989https://pubs.acs.org/doi/10.1021/ja00205a052https://doi.org/10.1021/ja00205a052research-articleACS PublicationsRequest reuse permissionsArticle...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSteric control of metal-thiolate coordination: synthesis and structure monomeric cobalt(II) copper(I) thiolate complexesStephen A. Koch, Ronald Fikar, Michelle Millar, Timothy O'SullivanCite this: Inorg. Chem. 1984, 23, 2, 121–122Publication Date (Print):January 1, 1984Publication History Published online1 May 2002Published inissue 1 January 1984https://pubs.acs.org/doi/10.1021/ic00170a001https://doi.org/10.1021/ic00170a001research-articleACS...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthetic models for the iron-sulfur protein rubredoxin: synthesis, structure, and properties of a highly symmetric iron(III) tetrathiolate anionMichelle Millar, Joe F. Lee, Stephen A. Koch, Ronald FikarCite this: Inorg. Chem. 1982, 21, 11, 4105–4106Publication Date (Print):November 1, 1982Publication History Published online1 May 2002Published inissue 1 November...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFour- and five-coordinate cobalt(II) thiolate complexes: models for the catalytic site of alcohol dehydrogenaseDouglas T. Corwin Jr., Ronald Fikar, Stephen A. KochCite this: Inorg. Chem. 1987, 26, 19, 3079–3080Publication Date (Print):September 1, 1987Publication History Published online1 May 2002Published inissue 1 September 1987https://pubs.acs.org/doi/10.1021/ic00266a001https://doi.org/10.1021/ic00266a001research-articleACS PublicationsRequest...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTetrakis(2-methoxy-5-methylphenyl)dichromiumF. Albert Cotton, Stephen A. Koch, and Michelle MillarCite this: Inorg. Chem. 1978, 17, 8, 2084–2086Publication Date (Print):August 1, 1978Publication History Published online1 May 2002Published inissue 1 August 1978https://pubs.acs.org/doi/10.1021/ic50186a010https://doi.org/10.1021/ic50186a010research-articleACS PublicationsRequest reuse permissionsArticle Views407Altmetric-Citations53LEARN ABOUT THESE...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRuthenium and osmium thiolate compoundsStephen A. Koch Michelle MillarCite this: J. Am. Chem. Soc. 1983, 105, 10, 3362–3363Publication Date (Print):May 1, 1983Publication History Published online1 May 2002Published inissue 1 1983https://pubs.acs.org/doi/10.1021/ja00348a082https://doi.org/10.1021/ja00348a082research-articleACS PublicationsRequest reuse permissionsArticle Views248Altmetric-Citations49LEARN ABOUT THESE METRICSArticle Views are the...
Dithiolate bridging Ni−Fe complexes [(dppe)NiII(μ-SEt)2FeII(CN)2(CO)2]6 and [(dppe)NiII(μ-pdt)FeII(CN)2(CO)2] [dppe = 1,2-bis(diphenylphosphino)ethane pdt 1,3-propanedithiolate] have been synthesized structurally characterized as structural analogues of the active site hydrogenase enzymes. The synthesis starts from key intermediate fac-[Fe(CN)2(CO)3I]−. [(dppe)NiII(μ-SEt)2FeII(CN)2(CO)2]6, which features a near-planar diethanethiolate-bridged rhomb, arrangement 2CN− ligands is cis to each...