13657-09-5Relevant articles and documents
Photodissociation at 193 nm of Cyclooctatetraene and Styrene into Benzene and Acetylene
Yu, C. F.,Youngs, F.,Bersohn, R.,Turro, N. J.
, p. 4409 - 4412 (1985)
When irradiated in a molecular beam at 193 nm, both cyclooctatetraene and styrene dissociate into benzene and acetylene.The average kinetic energy release is 12percent of the available energy in both cases.So that the mechanism of the dissociation of styrene could be determined the ratio of mass 26 to mass 27 (C2H2/C2HD) was measured for C6H5CDCH2 and C6H5CHCH2 and found to be 1.46 +/- 0.10 and 2.29 +/- 0.10, respectively.These numbers rule out cyclooctatetraene as an intermediate in the dissociation of styrene.A bicycloocta-2,4,7-triene intermediate which can tautomerize by 1,3 hydrogen atom jumps in the smaller ring explains all the experimental results.
Photochemical H2 Evolution from Bis(diphosphine)nickel Hydrides Enables Low-Overpotential Electrocatalysis
Castellano, Felix N.,Kurtz, Daniel A.,Miller, Alexander J. M.,Stratakes, Bethany M.,Wells, Kaylee A.
supporting information, p. 21388 - 21401 (2021/12/17)
Molecules capable of both harvesting light and forming new chemical bonds hold promise for applications in the generation of solar fuels, but such first-row transition metal photoelectrocatalysts are lacking. Here we report nickel photoelectrocatalysts for H2 evolution, leveraging visible-light-driven photochemical H2 evolution from bis(diphosphine)nickel hydride complexes. A suite of experimental and theoretical analyses, including time-resolved spectroscopy and continuous irradiation quantum yield measurements, led to a proposed mechanism of H2 evolution involving a short-lived singlet excited state that undergoes homolysis of the Ni–H bond. Thermodynamic analyses provide a basis for understanding and predicting the observed photoelectrocatalytic H2 evolution by a 3d transition metal based catalyst. Of particular note is the dramatic change in the electrochemical overpotential: in the dark, the nickel complexes require strong acids and therefore high overpotentials for electrocatalysis; but under illumination, the use of weaker acids at the same applied potential results in a more than 500 mV improvement in electrochemical overpotential. New insight into first-row transition metal hydride photochemistry thus enables photoelectrocatalytic H2 evolution without electrochemical overpotential (at the thermodynamic potential or 0 mV overpotential). This catalyst system does not require sacrificial chemical reductants or light-harvesting semiconductor materials and produces H2 at rates similar to molecular catalysts attached to silicon.
Iridium(iii) catalyzed trifluoroacetoxylation of aromatic hydrocarbons
Bischof, Steven M.,Hashiguchi, Brian G.,Lokare, Kapil S.,Gunsalus, Niles,Yousufuddin, Mohammed,Periana, Roy A.
, p. 35639 - 35648 (2014/12/10)
A tridentate, NNC-tb (where NNC-tb = 2-(pyridin-2-yl)benzo[h]quinoline) ligated IrIII complex (NNC-tb)Ir(Ph)(4-MePy)(TFA), 11 along with analogues are very active for CH activation as evidenced by rapid catalytic H/D exchange between benzene and trifluoroacetic acid-d1 (DTFA). The complexes were examined with a variety of oxidants for the catalytic conversion of benzene to phenyltrifluoroacetate. Herein, the synthesis and characterization of (NNC-tb)Ir complexes is described along with the reactivity of these complexes towards arenes and alkanes.
TRIDENTATE (NNC) CATALYSTS FOR THE SELECTIVE OXIDATION OF HYDROCARBONS
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Page/Page column 12, (2009/09/28)
The synthesis of discrete, air, protic, and thermally stable transition metal NNC complexes that catalyze the CH activation and functionalization of alkanes and arenes is disclosed. Methods for the selective conversion of methane to methanol or methyl esters in acidic and neutral media are disclosed.
