@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/101390,
    title ="Electrocatalytic transformations with small molecule substrates",
    author = "Peters, Jonas Christopher",
    
    
    
    pages = "INOR-0426",
    month = "March",
    year = "2020",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20200219-132442965",
    note = "© 2020 American Chemical Society.",
    revision_no = "9",
    abstract = "As distributed sources of renewable energy become increasingly widespread it is incumbent upon the catalysis community to define new types of multi-electron redox catalysis that can be efficiently coupled to these energy sources. The field of electrocatalysis serves an essential role in this context and, as such, has emerged at the forefront of catalysis research. In this talk I will describe recent efforts by our group at Caltech to explore new types of electrocatalytic transformations within the broad context of renewable energy conversion schemes.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/97752,
    title ="In situ nanostructuring and stabilization of polycrystalline copper electrodes with organic salt additives promotes CO_2 reduction to ethylene",
    author = "Thevenon, Arnaud and Rosas-Hernandez, Alonso",
    
    
    
    pages = "INOR-0267",
    month = "August",
    year = "2019",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20190812-090716368",
    note = "© 2019 American Chemical Society.",
    revision_no = "12",
    abstract = "The electrocatalytic conversion of CO_2 to hydrocarbons using renewable energy provides a sustainable pathway to produce carbon-neutral fuels and value-added chems. However, a great challenge remains to develop efficient and robust electrocatalysts with high selectivity profile for any single product, at low overpotential. To this end, nanostructured copper electrodes have shown enhanced selectivity for C-C coupled products during CO_2 electroredn. reaction (CO_2RR). Nevertheless, inexpensive means to maintain structural stability during catalysis remain a challenge to sustained activity and selectivity. Herein, we report the combination of polycryst. copper and pyridinium-based additives as a simple system to achieve and maintain high selectivity of up to 60-70 % for C≥2 products, for 43h, in 0.1M KHCO_3. Several roles have been demonstrated for the org. additive, including: the formation of \"nanocube-like\" nanostructures by corrosion of the copper surface; the stabilization of the nanostructures during catalysis by formation of a protective org. layer; and the promotion of C≥2 products. Overall, this simple and cheap technic opens promising opportunities in preserving nanostructures during catalysis and could be applied to many systems already reported in the literature.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/94111,
    title ="Making bonds with copper and light",
    author = "Peters, Jonas Christopher",
    
    
    
    pages = "INOR-0166",
    month = "April",
    year = "2019",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20190325-100053152",
    note = "© 2019 American Chemical Society.",
    revision_no = "11",
    abstract = "Photochem. has had a rich history within the inorg. community, and there is broad current interest in using inorg. species to mediate photoinduced reactions that are important to reaction development. Some years ago our lab discovered a family of unusually emissive copper complexes featuring a combination of amide and phosphine ligands. This discovery led us to explore their efficacy in mediating Ullmann-type cross-coupling reactions, reasoning that a copper complex might play the role of both photoreductant to generate an org. radical R.bul. and also be a key reaction partner in a subsequent bond forming step, for example via the reaction of the liberated org. radical with a resulting copper(II)-amide to form an R-N bond. As we have explored the scope of this type of reactivity we have discovered an array of conditions/cocktails that mediate efficient photoinduced, Cu-mediated couplings under mild conditions, motivating us to try to understand what Cu-mediated mechanisms may be involved in these processes. In this talk I will provide an update of some of the key mechanistic questions we have addressd in the context of these C-X couplings mediated by copper and light.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/94112,
    title ="Protonated metallocenes as extremely reactive PCET reagents",
    author = "Peters, Jonas Christopher",
    
    
    
    pages = "INOR-0520",
    month = "April",
    year = "2019",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20190325-101909054",
    note = "© 2019 American Chemical Society.",
    revision_no = "10",
    abstract = "While the cyclopentadienyl ring has a venerable history in the development of organometallic chem., it is most commonly viewed as a robust ancillary ligand that does not itself participate in reaction chem. While there are of course many exceptions to this rule, an emerging and fascinating type of reactivity that is relevant to catalytic redns. of small mol. substrates (e.g., nitrogen) involves the in situ protonation of a metallocene ring to generate a highly reactive C-H bond. Such protonated metallocenes can serve as remarkably strong PCET reagents characterized by BDFE's well below 35 kcal/mol. Because of this, they afford an opportunity to initiate challenging redns. where the kick-off step is the generation of a new and very weak E-H bond (e.g., M(NNH)). Our lab has been exploring the role of decamethylcobaltocene as a participant in this type of reactivity in the context of Fe-mediated nitrogen fixation, and as such we have spent considerable effort characterizing the protonated form of this well-known metallocene reductant. In this talk I will describe our recent findings relating to spectroscopic characterization, exptl. and theor. elucidating phys. parameters relating to the BDFE values of the reactive C-H bonds formed upon metallocene protonation, and the reactivity patterns of such species.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/85775,
    title ="Organometallic species at the heart of small molecule reduction catalysis",
    author = "Peters, Jonas",
    
    
    
    pages = "INOR-111",
    month = "March",
    year = "2018",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20180412-093842222",
    note = "© 2018 American Chemical Society.",
    revision_no = "8",
    abstract = "Our lab has an ongoing interest in exploiting organometallic systems to elucidate new reactivity patterns with\nsmall mol. substrates, such as nitrogen, cyanide, carbon monoxide, and carbon dioxide. Some of our most\nrecent strategies and findings in this area, relevant to stoichiometric and catalytic reductive transformations, will\nbe described. The talk will emphasize both reactivity patterns and fundamental mechanistic issues.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/81317,
    title ="Synthetic iron nitrogenases",
    author = "Peters, Jonas C.",
    
    
    
    pages = "INOR-310",
    month = "August",
    year = "2017",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20170911-145558818",
    note = "© 2017 American Chemical Society.",
    revision_no = "10",
    abstract = "Nitrogen redn. to NH_3 is a requisite transformation for life and new technologies for NH synthesis are a longstanding\ngoal of the chem. community. Distinct from the industrial Haber-Bosch process, the Fe-rich cofactors\nof nitrogenase enzymes facilitate this transformation under ambient temp. and pressure, but exactly how they\ndo so remains poorly understood. A central element of debate has been the site(s) of dinitrogen coordination\nand redn., and the types of intermediates crit. to the nitrogen redn. pathway. Fe is the only transition metal\nessential to all nitrogenases, and recent biochem. and spectroscopic data have implicated Fe as the most likely\nsite of N_2 binding in FeMo-co. These observations help to motivate efforts towards functional Fe catalysts, and\nit is in this context that our lab has for some years pursued the development of synthetic Fe complexes that\ncatalyze N_2-to-NH_3 conversion. These functional model systems have established that a single Fe site is capable\nof stabilizing the various N_xH_y ligands generated en route to NH_3 formation. Our most recent efforts have\ntargeted improving the efficiency of these synthetic Fe nitrogenases via exploring various conditions and\ncatalyst scaffolds, and using both expt. and theory to better understand the mechanisms by which these\ncatalysts function. This lecture will highlight our most recent findings.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/66650,
    title ="Mechanistic investigation of proton reduction by cobaloximes: Insight from H2 oxidation kinetics",
    author = "Del Ciello, Sarah A. and Winkler, Jay R.",
    
    
    
    pages = "INOR-889",
    month = "March",
    year = "2016",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20160504-105818808",
    note = "© 2016 American Chemical Society.",
    revision_no = "10",
    abstract = "Cobaloximes are a class of earth- abundant proton redn. catalysts that have been known since the 1980's. Previous studies\nhave come to conflicting conclusions about the mechanism of proton redn. by these catalysts, with evidence existing for both a\nhomolytic and heterolytic mechanism. In this work, kinetic anal. of the reverse reaction is used to gain further insight.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/66122,
    title ="Nitrogen fixation with iron complexes",
    author = "Peters, Jonas C. and Del Castillo, Trevor J.",
    
    
    
    pages = "INOR-631",
    month = "March",
    year = "2016",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20160413-112733252",
    note = "© 2016 American Chemical Society.",
    revision_no = "12",
    abstract = "Nitrogen redn. to NH_3 is a requisite transformation for life. While it is widely appreciated that the Fe- rich cofactors of\nnitrogenase enzymes facilitate this transformation, how they do so remains poorly understood. It is known that Fe is the only\ntransition metal essential to all nitrogenases, and recent biochem. and spectroscopic data have implicated Fe as the likely site of\nN_2 binding in FeMo-co. These observations motivate studies of functional Fe catalysts as models. In this talk, Fe complexes\nthat catalyze the redn. of N_2 to NH_3 will be discussed. Our lab's most recent data for various Fe complexes, aimed at\nimproving catalysis, providing mechanistic insight pertinent to the catalysis, and exposing new reactivity patterns, will be\nemphasized.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/64949,
    title ="Mechanistic insights into photo-induced, copper-catalyzed alkylations of amines",
    author = "Ahn, Jun Myun and Hannoun, Kareem",
    
    
    
    pages = "WRM-134",
    month = "November",
    year = "2015",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20160302-081446965",
    note = "© 2015 American Chemical Society.",
    revision_no = "13",
    abstract = "Photoinduced, copper-catalyzed cross-couplings have emerged as an attractive class of lightdriven\ntransformations to construct carbon-nitrogen bonds in recent years. Despite the\nbroadening scope with respect to coupling partners, the understanding of the operating\nmechanisms has been limited to date. Herein, a mechanistic investigation of a photoinduced,\ncopper-catalyzed cross-coupling of amines and alkyl halides, including spectroscopic evidence\nfor a copper intermediate, is presented.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/60291,
    title ="Diiron μ-thiolate complexes that bind N2 across multiple oxidation states: Towards new structural/functional models of nitrogenase",
    author = "Creutz, Sid and Peters, Jonas",
    
    
    
    pages = "INOR-706",
    month = "August",
    year = "2015",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20150916-161306847",
    note = "© 2015 American Chemical Society.",
    revision_no = "8",
    abstract = "While known biol. metallocofactors involved in nitrogen redn. (e.g. FeMoco) invariably contain iron in a sulfur-rich coordination\nenvironment, synthetic examples of transition metal model complexes (esp. iron) that bind N while also featuring sulfur donor\nligands remain rare. In order to address this deficiency, we have synthesized an unusual series of diiron complexes featuring\nthiolate and dinitrogen ligands. A new binucleating ligand scaffold is introduced that supports a Fe(SAr)Fe diiron subunit that\ncoordinates two dinitrogen mols. across at least three oxidn. states (Fe(II)Fe(II), Fe(II)Fe(I), and Fe(I)Fe(I)). This scaffold\nalso supports dinitrogen binding with hydride as a co-ligand. Synthetic model complexes of these types are desirable to\ninform and evaluate hypotheses regarding Fe-mediated nitrogen fixation in biol., and may help to delineate the role of the Fe-SFe\nunit in facilitating this challenging reaction.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/60316,
    title ="H2 oxidation by cobaloximes: Mechanistic insight into hydrogen evolution catalysis",
    author = "Del Ciello, Sarah A. and Winkler, Jay R.",
    
    
    
    pages = "INOR-685",
    month = "August",
    year = "2015",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20150918-085547603",
    note = "© 2015 American Chemical Society.",
    revision_no = "10",
    abstract = "Cobaloximes are a series of macrocyclic cobalt complexes that have been shown to catalyze the hydrogen\nevolution reaction (HER) at low overpotentials. There has been much debate about the mechanism of this\nreaction, particularly with regard to H-H bond formation. As catalysts that operate close to the thermodn.\npotential, cobaloximes show some degree of reversibility, oxidizing hydrogen in the presence of base to form\nthe conjugate acid. Presented here are kinetic studies of the cobaloxime-mediated oxidn. of hydrogen in the\npresence of base. Insight into the bifurcation between homolytic and heterolytic mechanisms of cobaloximecatalyzed\nHER is gained by studying the microscopic reverse reaction.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/60332,
    title ="Molecular Fe-mediated nitrogen fixation catalysis: Improving turnover and mechanistic insights",
    author = "Peters, Jonas C. and Creutz, Sidney E.",
    
    
    
    pages = "INOR-293",
    month = "August",
    year = "2015",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20150918-135114265",
    note = "© 2015 American Chemical Society.",
    revision_no = "11",
    abstract = "Our lab. at Caltech has been exploring iron complexes for the redn. of nitrogen to ammonia in the presence of\nsources of electrons and protons at low temp. We have recently discovered several iron catalytsts that mediate\nthis reaction, and are now focused on understanding the mechanism(s) by which these iron catalysts operate.\nWe are particularly interested in establishing whether the distal (or Chatt), alternating, and/or a hyrbid\nmechanism is at work for these iron catalysts. We have also been exploring a no. of reaction parameters that\nsubstantially increase the TON of some of these iron systems. Finally, we have been exploring related potential\ncatalysts that feature late metals other than iron such as cobalt. My talk, which is submitted in honor of the late\nProfessor Gregory L Hillhouse, will provide a snapshot of our progress to date in this area of high energy\norganometallic chem.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/60288,
    title ="Tunable spin equilibria in four-coordinate iron trisphosphine phosphiniminato complexes",
    author = "Creutz, Sid and Peters, Jonas",
    
    
    
    pages = "INOR-736",
    month = "August",
    year = "2015",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20150916-160632073",
    note = "© 2015 American Chemical Society.",
    revision_no = "9",
    abstract = "A series of four-coordinate iron tris(phosphine)borate phosphiniminato complexes (PhBP3RFeNPR'3) with\nvarying alkyl or aryl substituents (R = Ph, CH2Cy, m-terphenyl, iPr; R' = Ph, Cy, Et) have been synthesized and\ncrystallog. characterized. The spin states of these complexes vary depending on the ligand substituents, and\nmost undergo spin-crossover (S = 0 to S = 2) at temps. near or above room temp. in soln. and in the solid\nstate. The change in spin state also involves a significant change in the degree of π-bonding between Fe and\nthe N of the phosphiniminato ligand as well as dramatic changes in Fe-P bond lengths. Spin-crossover is\naccompanied by striking changes in the UV-visible absorption spectra, which allowed for quant. modeling of the\nthermodn. parameters (ΔH and ΔS) of the spin equil. The complexes and their spin equil. have also been\nstudied by paramagnetic NMR, IR spectroscopy, Moessbauer spectroscopy, and soln.- and solid-state\nmagnetometry. These studies lead to qual. correlations between the steric and electronic properties of the\nligand substituents and the enthalpy and entropy changes assocd. with the spin equil. in soln. This series of\ncomplexes emphasizes the importance of considering sep. entropic and enthalpic effects when attempting to\nunderstand and predict trends in spin-crossover temps. (TC).",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/48375,
    title ="Catalytic cross-\u200bcoupling with copper and light",
    author = "Peters, Jonas C. and Fu, Gregory",
    
    
    
    pages = "INOR 607",
    month = "August",
    year = "2014",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20140812-105957073",
    note = "© 2014 American Chemical Society.",
    revision_no = "8",
    abstract = "Carbon-nitrogen bond-forming reactions of amines with aryl halides to generate arylamines (anilines), mediated by a stoichiometric copper reagent at elevated temp. (>180 °C), were first described by Ullmann in 1903. Recent advances in catalytic Ullmann-type cross-couplings make these bond-forming processes powerful tools for org. synthesis. In this talk I will describe a recent collaborative effort between the Fu and Peters research groups at Caltech to develop photo-induced, copper-catalyzed C-X cross-couplings (X = N, S, O, C) as a methodolgically simple, mild approach to Ullmann-type bond constructions.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/48359,
    title ="Efforts towards novel catalysts for N_2 reduction to NH_3",
    author = "Del Castillo, Trevor J. and Suess, Daniel L. M.",
    
    
    
    pages = "INOR 802",
    month = "August",
    year = "2014",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20140811-155351287",
    note = "© 2014 American Chemical Society.",
    revision_no = "11",
    abstract = "In part as an effort to probe the viability of a single iron site hypothesis for the binding and conversion of N_2 to NH_3 by nitrogenase enzymes, our group has recently reported a tris(phosphine)borane supported mononuclear Fe system that can stabilize many potentially relevant nitrogenous ligands and ligand motifs, such as N_2, N_2H_4, NH_3, NH_2, N_2R_2, N_2R, and NR. This system has also been shown to mediate catalytic conversion of N_2 to NH_3 at low temp. in the presence of strong acid and reductant. More recently we reported a related tris(phosphine)alky supported Fe system that also mediates N_2 to NH_3 conversion under similar conditions. Common features of these systems that may be crit. to the obsd. nitrogen fixation reactivity include local approx. three-fold rotational symmetry at the metal center as well as a flexible axial interaction to a light atom, either carbon or boron. This paper will describe recent efforts to extend this nitrogen fixation catalysis to novel systems and the elucidation of important factors in achieving this reactivity.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/48325,
    title ="Intra-\u200bmolecular proton transfer and hydrogen evolution mechanism in cobalt catalysts",
    author = "Huo, Pengfei and Uyeda, Christopher",
    
    
    
    pages = "PHYS 134",
    month = "August",
    year = "2014",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20140811-133647033",
    note = "© 2014 American Chemical Society.",
    revision_no = "11",
    abstract = "Hydrogen generation through catalytic water splitting is a promising strategy for solar energy storage and clean renewable energy generation. In most hydrogen evolution catalysts, external energetic costs to initiate the reaction are anti-correlated with the overall turnover frequency for the catalyst. This has been a limitation for designing more efficient catalysts that evolve hydrogen with both a high reactive rate and a low energetic cost. Here, we report the synthesis and characterization of cobalt-based (pyridine-diimine-dioime) catalysts for hydrogen evolution. A combination of theor. and exptl. anal. suggests that the complex can facilitate an intra-mol. proton transfer reaction from protonated pyridine to cobalt. This process produces CoIII hydride as the key intermediate for hydrogen evolution. Our calcns. indicate a significantly lower energetic barrier for hydrogen generation process with a CoII hydride intermediate compared to the corresponding CoIII hydride intermediate, suggesting that the CoII hydride is the key reactive species for hydrogen generation. Using these insights, we propose a strategy to decouple the anti-correlation between external energetic costs and the catalytic turnover frequency, which provides a promising design principle for more efficient hydrogen evolution catalysts.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/48368,
    title ="Low valent bisphosphinoborane transition metal compounds: Unusual coordination chemistry and E-\u200bH bond activation",
    author = "Nesbit, Mark A. and Suess, Daniel L. M.",
    
    
    
    pages = "INOR 669",
    month = "August",
    year = "2014",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20140812-083916351",
    note = "© 2014 American Chemical Society.",
    revision_no = "8",
    abstract = "Recently there has been great interest in the use of transition metal compds. supported by a redox active ligand which are able to serve as bifunctional catalysts for two electron processes. We have previously shown that iron aminoimide compds. bearing bisphosphinoborane ligands activate of Si-H and H-H bonds to generate hydrazido and amide species. We have also reported activation of H-H and Si-H bonds in the context of catalytic hydrogenation of olefins and hydrosilylation of aldehydes by related low valent nickel compds. Computational studies of the Ni system have alluded to the importance of the M-B interaction in the activation of E-H bonds. The M-B unit in these compds. can be thought of as a transition metal based frustrated Lewis pair with an electron rich metal center acting as the base with the nearby Lewis acidic borane acting as a hydride acceptor. Efforts to expand this chem. to other low valent metal centers supported by a similar ligand scaffold and the resultant coordination chem., E-H bond activation chem. and catalytic activity towards some small mols. will be discussed.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/48338,
    title ="Photoinduced, copper-\u200bcatalyzed reactivity of unactivated aryl and alkyl halides and photophysical characterization of a Cu(I) bis(carbazolide) complex",
    author = "Ratani, Tanvi S. and Peters, Jonas C.",
    
    
    
    pages = "ORGN 665",
    month = "August",
    year = "2014",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20140811-145345755",
    note = "© 2014 American Chemical Society.",
    revision_no = "7",
    abstract = "In a 2012 result from the Peters and Fu groups published in Science, a luminescent Cu(PPh3)2(carbazolide) complex was able to perform C-N Ullmann coupling under unusually mild conditions with a 100W-mercury lamp. This study is to date the most substantial evidence toward a single electron transfer (SET) mechanism for Ullmann coupling. Since this result, there have been several joint publications from the Peters and Fu groups entailing ligandless, photo-induced, copper-catalyzed C-N coupling of carbazoles with alkyl halides, other nitrogen nucleophiles with more diverse halide electrophiles, alkylation of amides, as well as carbon-sulfur coupling under mild conditions. This work will describe new coupling reactions which have been obsd. with use of a similar photoinduced, copper-catalyzed methodol., identifying an SET step in the mechanism. It will also report photophys. characterization and data of a copper bis(carbazolide) intermediate in C-N Ullmann coupling.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/48345,
    title ="Stabilization of mononuclear two-\u200bcoordinate Fe(0) and Co(0) complexes",
    author = "Ung, Gael and Peters, Jonas C.",
    
    
    
    pages = "INOR 1055",
    month = "August",
    year = "2014",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20140811-150719732",
    note = "© 2014 American Chemical Society.",
    revision_no = "7",
    abstract = "Low coordinate iron and cobalt complexes are sought after for their catalytic applications as well as their potential as bond activators. Most of the two-coordinate iron and cobalt species are in the formal +II oxidn. state, and are stabilized with extremely bulky X-type ligands. Formally zero-valent two-coordinate transition metal species are exceedingly rare and neither two-coordinate Fe(0) nor Co(0) complexes have been characterized to date. We will present the synthesis of neutral two-coordinate mononuclear iron and cobalt complexes using the vital cyclic (alkyl)(amino)carbenes as ligands. Their unusual properties and reactivity will also be discussed.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/45220,
    title ="Fixing nitrogen with iron complexes",
    author = "Peters, Jonas C. and Anderson, John S.",
    
    
    
    pages = "INOR-132",
    month = "March",
    year = "2014",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20140425-092615947",
    note = "© 2014 American Chemical Society.",
    revision_no = "10",
    abstract = "Nitrogen redn. to NH_3 is a requisite transformation for life. While it is widely appreciated that the Fe-rich cofactors of\nnitrogenase enzymes facilitate this transformation, how they do so remains poorly understood. A central element of debate has\nbeen the site(s) of dinitrogen coordination and redn. in these cofactors. As Fe is the only transition metal essential to all\nnitrogenases, prepg. functional nitrogen redn. catalysts that feature iron has been a longstanding goal. In this talk I will\ndiscuss our lab's most recent efforts directed towards the prepn. of nitrogen-fixing Fe complexes.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/41899,
    title ="Catytic N2 reduction to NH3 by a mononuclear Fe complex",
    author = "Peters, Jonas C. and Anderson, John S.",
    
    
    
    pages = "INOR-191",
    month = "September",
    year = "2013",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20131011-132856579",
    note = "© 2013 American Chemical Society.",
    revision_no = "11",
    abstract = "Our group has suggested that a hemi-labile role may be played by the interstitial light X-atom of the FeMocofactor,\nmost recently assigned as C. Such a role would enable a high degree of conformational and redox\nflexibility at a single iron N_2 binding site. In particular, a hemi-labile behavior of the interstitial C-atom would\nallow an iron binding site to modulate its local geometry by varying its degree of interaction with the C-atom\nunder crude local three-fold symmetry, possibly sampling trigonal bipyramidal, trigonal pyramidal, and/or\npseudotetrahedral geometries as a function of the nature of the state of redn. of the nitrogenous ligand. To test\nthese ideas, our group has been exploring a range of 4- and 5-coordinate iron model complexes that exhibit local\nthree-fold symmetry and feature a host of nitrogenous ligands (e.g., N_2, N_2H_4, NH_3, NH_(2-), NR^(2-), N^(3-)) in an axial\nsubstrate-binding site trans to a light atom (e.g., B or C). These single-iron site inorg. model complexes show\npromise for the catalytic redn. of nitrogen to ammonia in the presence of protons and electrons in soln. at low\ntemp. This talk will provide an update on our lab's most recent progress in this area.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/41897,
    title ="Iron dinitrogen complexes and nitrogen fixation with tris(phosphine)alkyl ligands",
    author = "Peters, Jonas C. and Rittle, Jonathan",
    
    
    
    pages = "INOR-270",
    month = "September",
    year = "2013",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20131011-130112398",
    note = "© 2013 American Chemical Society.",
    revision_no = "11",
    abstract = "The interstitial light atom of the FeMo-cofactor of MoFe-Nitrogenase has recently been identified as a C-atom, and hypotheses\nregarding its possible role/s warrant synthetic model studies. We have previously suggested that one role this structural unit\nmay play is to modulate an Fe-C interaction upon substrate binding and redn. at the cofactor. To explore this idea, we have\nbegun to target ligands whereby a comparatively loosely bound C-atom is installed on an Fe center in a position trans to where\nsubstrates such as nitrogen bind. I will discuss the fundamental coordination chem. of these ligands at iron and other late\nfirst row metals, and will describe their efficacy towards the catalytic redn. of dinitrogen to ammonia.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/39381,
    title ="Benchmarking electrocatalysts for hydrogen evolution and oxygen evolution",
    author = "McCrory, Charles C. and Jung, Suho",
    
    
    
    pages = "INOR 1207",
    month = "April",
    year = "2013",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20130716-081832711",
    note = "© 2013 American Chemical Society.",
    revision_no = "14",
    abstract = "Objective evaluation of the activity of electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction\n(HER) is of fundamental importance for the development of solar water-splitting devices. However, current testing methods\nemployed in catalysis research are far from standardized, making it difficult to cross-compare the activity and stability of these\nsystems. In this presentation, an overview of the std. methods used within the Benchmarking facility of the Joint Center for\nArtificial Photosynthesis (JCAP) will be discussed. In particular, the presentation will focus on std. techniques used for detg.\nelectrochem.-active surface areas and measuring electrocatalytic activity and catalyst stability. Figures of merit for\nelectrocatalytic hydrogen-evolving and oxygen-evolving reactions will also be discussed. Finally, the results of using this\nbenchmarking methodol. to study and compare over 50 electrodeposited HER and OER catalysts in both acidic and basic\nconditions will be presented.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/39428,
    title ="Bifunctional catalysis with boratranes",
    author = "Peters, Jonas C.",
    
    
    
    pages = "INOR 1064",
    month = "April",
    year = "2013",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20130717-160629760",
    note = "© 2013 American Chemical Society.\n",
    revision_no = "13",
    abstract = "Transition metal catalyzed bond forming reactions often involve formal two-electron redox steps (e.g. Oxidative addn. and\nreductive elimination). Noble metal catalysts are commonly used in these reactions due, in part, to their propensity to facilitate\nthese multi-electron processes. By contrast, first row metal complexes often engage in 1-electron reaction steps. But there is\ngrowing interest and substantial promise in developing catalysts for bond forming/cleavage reactions based on earth abundant\nmid-to-late first-row transition metals. First row metallaboratranes are appealing as catalysts because of the boron center's\nability to stabilize low valent metals and serve as a hydride acceptor. As such, metallaboratranes can mediate 2-electron\nreaction steps. Akin to frustrated Lewis pairs (FLPs) that employ main group donor and acceptor partners, our group has\nrecently reported a demonstrative example wherein nickel boratranes facilitate H_2 activation and catalytic hydrogenations. We\nhave since been exploring E-H bond addn. across M-B bonds more generally, for example where M = Fe, Co, and Ni. In this talk\nI will summarize what we have learned to date, and where we think ripe opportunities exist for productive bifunctional catalysis.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/39462,
    title ="Bonding in silatranes and boratranes and where it gets confusing",
    author = "Peters, Jonas C.",
    
    
    
    pages = "INOR 686",
    month = "April",
    year = "2013",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20130719-084608012",
    note = "© 2013 American Chemical Society.",
    revision_no = "10",
    abstract = "Our group has reported an array of mid-to-late first row transition metal complexes supported by tris(phosphino)silyl and\ntris(phosphino)borane ligands. Some of these complexes have interesting electronic structures and warrant consideration of\nappropriate valence and oxidn. state assignments. Because of the highly covalent nature of these complexes no limiting\nformalism is ever to be fully satisfying. In this talk I will present some of the more interesting and hence more confusing\nscenarios that have arisen, including cases were 1-electron sigma bonding may be prevalent.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/39497,
    title ="C-N cross coupling with Cu and light",
    author = "Peters, Jonas C.",
    
    
    
    pages = "INOR 632",
    month = "April",
    year = "2013",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20130722-131615713",
    note = "© 2013 American Chemical Society.\n",
    revision_no = "10",
    abstract = "Carbon-nitrogen bond-forming reactions of amines with aryl halides to generate arylamines (anilines), mediated by a\nstoichiometric copper reagent at elevated temp. (>180 °C), were first described by Ullmann in 1903. Advances in catalytic\nUllmann C-N cross-couplings make this and related C-N bond-forming processes powerful tools for org. synthesis. Gaining\ninsight into the mechanisms by which Ullmann couplings proceed, as well as demonstrating new pathways for accomplishing this\nimportant bond construction, is an important objective. In this talk I will describe the first examples of photoinduced Ullmann CN\ncoupling reactions. These reactions arise from fundamental studies of a new class of highly emissive copper complexes\nsupported by phosphine and amide ligands. Model studies suggested to us that the excited states of these complexes likely\nfeature substantial aminyl radical character. As such they offered promise to engage in C-N cross coupling reactions that\nproceed via single electron transfer (SET) from the copper complex excited state to an aryl halide coupling partner. In close\ncollaboration with Professor Gregory Fu and his group at Caltech, stoichiometric and catalytic C-N cross couplings using copper\nhave now been realized at room temp. and even at -40 °C. An array of data are consistent with an SET mechanism,\nrepresenting the most substantial exptl. support to date for the viability of this pathway for Ullmann C-N couplings.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/39586,
    title ="Fixing nitrogen with iron complexes",
    author = "Peters, Jonas C.",
    
    
    
    pages = "INOR 28",
    month = "April",
    year = "2013",
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20130725-100657552",
    note = "© 2013 American Chemical Society.",
    revision_no = "10",
    abstract = "Our group has suggested that a hemi-labile role may be played by the interstitial light X-atom of the FeMo-cofactor, most\nrecently assigned as C. Such a role would enable a high degree of conformational and redox flexibility at a single iron N_2 binding\nsite. A spring-like behavior of the interstitial atom would allow an iron binding site to modulate its local geometry by varying its\ndegree of interaction with the light X-atom under crude local three-fold symmetry, possibly sampling trigonal bipyramidal,\ntrigonal pyramidal, and/or pseudotetrahedral geometries as a function of the nature of the state of redn. of the nitrogenous\nligand. To test these ideas, our group has been exploring a range of 4- and 5-coordinate iron model complexes that exhibit local\nthree-fold symmetry and feature a host of nitrogenous ligands (e.g., N_2, N_2H_4, NH_3, NH_2-, NR^2-, N^3-) in an axial substrate-binding\nsite. These inorg. model complexes will be discussed in the context of a single-iron site 'spring' hypothesis for nitrogen redn.",
}
@conference_item {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/33236,
    title ="Hydrogen evolution at low overpotentials",
    author = "Peters, J. C.",
    
    
    
    
    month = "December",
    year = "2010",
    
    
    
    
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20120815-144745225",
    note = "© 2012 American Chemical Society.",
    revision_no = "12",
    abstract = "Global energy demands motivate us to consider whether technol. valid solns. to renewable energy sources can be found.\nChemists have for decades wanted to mimic biol. photosynthesis, but the vast no. of scientific and technol. challenges\nassocd. with such an endeavor have precluded the development of chem. systems that are efficient. Our belief is that\nphotocatalysts for water-splitting, interfaced with a photoelectrode membrane, may some day provide the soln. to clean\nand efficient, carbon-free fuel from sunlight. The types of catalysts that might in principle efficiently mediate hydrogen or\noxygen evolution are chem. distinct and thus need to meet independent design criteria. A crit. chem. question therefore\nbecomes: How can we generate efficient mol. catalysts for each of the half-cell reactions of water-splitting, and how can\nwe get these catalysts to work in concert with one another, and also with a photoelectrode membrane, to generate\nstorable fuel form sunlight and water Moreover, how can we redirect the protons and electrons derived from the photooxidn.\nof water to fix carbon substrates such as CO2Our group has been actively engaged in a collaborative effort\nbetween several universities and national labs, supported by the NSF, called 'Powering the Planet'. The goal of this\ncollaborative center is to meet the fundamental science challenges assocd. with each element of a photosynthetic app.\nAs our group's expertise pertains to homogeneous catalysis, we have been exploring promising catalyst systems that\nmediate proton redn. to hydrogen at unusually low overpotentials.",
}