14940-63-7Relevant articles and documents
Vibrational excitation of H2O and HOD molecules produced by reactions of OH and OD with cyclo-C6H12, n-C4H10, neo-C5H12, HCI, DCI and NH3 as studied by infrared chemiluminescence
Butkovskaya,Setser
, p. 2434 - 2447 (1998)
The room-temperature reactions of OH(OD) radicals with cyclo-C6H12,n-C4H10, and neo-C5H12 have been investigated by observing the infrared chemiluminescence from the H2O(HOD) molecules generated in a fast-flow reactor. These hydrocarbon molecules are representative for abstraction from secondary and primary C-H bonds. The total vibrational energy released to H2O(HOD) was in the range of (fv)=0.55-0.65. The majority (80%-85%) of the vibrational energy is in the stretching modes and the main energy release is to the local mode associated with the new OH bond. The dynamics associated with the energy disposal to H2O(HOD) resemble the H+L-H dynamics for the analogous reactions of F atoms. The data from H2O and HOD are complementary because of the different collisional coupling between the energy levels of the v1. v2. and v modes: however, no specific isotope effect was found for the energy disposal to H2O versus HOD for reactions with the hydrocarbon molecules. In contrast, a very unusual isotope effect was found between the OH+HCl and OD+ HCl pairs The latter reaction gave the expected stretching mode excitation of HOD: however, the OH reaction gave H2O molecules with virtually no vibraitonal energy. This anomalous situation is partly associated with an inverse secondary kinetic-isotope effect, but the main isotope effect is on the dynamics of the energy disposal process itetf.
Ultrafast dynamics of hydrogen bond exchange in aqueous ionic solutions
Park, Sungnam,Odelius, Michael,Gaffney, Kelly J.
, p. 7825 - 7835 (2009)
The structural and dynamical properties of aqueous ionic solutions influence a wide range of natural and biological processes. In these solutions, water has the opportunity to form hydrogen bonds with other water molecules and anions. Knowing the time sca
Reaction pathways and site requirements for the activation and chemical conversion of methane on Ru-based catalysts
Wei, Junmei,Iglesia, Enrique
, p. 7253 - 7262 (2004)
Kinetic and isotopic tracer and exchange measurements were used to determine the identity and reversibility of elementary steps required for CH4 reforming reactions on Ru-based catalyst. CH4 reactions were limited by C-H bond activat
Quantitative spectroscopic and theoretical study of the optical absorption spectra of H2O, HOD, and D2O in the 125-145 nm region
Cheng, Bing-Ming,Chung, Chao-Yu,Bahou, Mohammed,Lee, Yuan-Pern,Lee,Van Harrevelt, Rob,Van Hemert, Marc C.
, p. 224 - 229 (2004)
Synchrotron radiation was used to determine the room temperature absorption spectra of water and its isotopomers D2O and HOD in absolute cross section units in the 125 to 145 nm wavelength region. The cross sections at a temperature of 300K were calculated by applying a Monte Carlo sampling over the initial rotational states of the molecules. Two more resonances were found at low energy in the case of HOD. The width of the resonances of 0.04 eV is the result of overlapping and narrower resonances in the spectra of molecules differing in rotational ground state.
Requirements for functional models of the iron hydrogenase active site: D2/H2O exchange activity in {(μ-SMe)(μ-pdt)[Fe(CO)2(PMe3)] 2+}[BF4-]
Georgakaki, Irene P.,Miller, Matthew L.,Darensbourg, Marcetta Y.
, p. 2489 - 2494 (2003)
Hydrogen uptake in hydrogenase enzymes can be assayed by H/D exchange reactivity in H2/D2O or H2/D2/H2O mixtures. Diiron(I) complexes that serve as structural models for the active site of iron hydrogenase are not active in such isotope scrambling but serve as precursors to FeIIFeII complexes that are functional models of [Fe]H2ase. Using the same experimental protocol as used previously for {(μ-H)(μ-pdt)[Fe(CO)2(PMe3)] 2+}, 1-H+ (Zhao et al. J. Am. Chem. Soc. 2001, 123, 9710), we now report the results of studies of {(μ-SMe)(μ-pdt)[Fe(CO)2(PMe3)]2 +}, 1-SMe+, toward H/D exchange. The 1-SMe+ complex can take up H2 and catalyze the H/D exchange reaction in D2/H2O mixtures under photolytic, CO-loss conditions. Unlike 1-H+, it does not catalyze H2/D2 scrambling under anhydrous conditions. The molecular structure of 1-SMe+ involves an elongated Fe...Fe separation, 3.11 A, relative to 2.58 A in 1-H+. It is proposed that the strong SMe- bridging ligand results in catalytic activity localized on a single FeII center, a scenario that is also a prominent possibility for the enzyme active site. The single requirement is an open site on FeII available for binding of D2 (or H2), followed by deprotonation by the external base H2O (or D2O).
Isotope effects in liquid water by infrared spectroscopy
Max, Jean-Joseph,Chapados, Camille
, p. 4626 - 4642 (2002)
The heavy and light liquid water (H2O-D2O) mixtures were studied by Fourier transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy. The deformation bands of liquid water clearly indicate the presence of the three typ
The dynamics of the OH + HD gas-phase reaction: Absolute reaction cross section and H/D atom product branching ratio
Brownsword,Hillenkamp,Schmiechen,Volpp,Wolfrum
, p. 325 - 331 (1997)
The dynamics of the OH + HD reaction were studied in the gas-phase using the laser photolysis/vacuum-UV laser-induced fluorescence pump-and-probe technique. Translationally energetic OH(2II) radicals with an average reagent translational energy of Ec.m. = 0.24 eV in the (OH-HD)-center-of-mass system were generated by the laser photolysis of H2O2 at 248 nm. Doppler profiles of nascent D and H atoms produced in reactive collisions of OH with room-temperature HD molecules were detected under single-collision conditions by VUV-LIF at the Lyman-α transition. For the OH + HD reaction an absolute reaction cross section of σrR(0.24 eV) = (0.14 ± 0.05) A2 was determined by means of a calibration method using OH + D2 as a reference reaction. The branching ratio for the OH + HD → H + HOD (D + H2O) product channels was measured to be ΓH/D = (1.2 ± 0.2).
Micropolarity and Hydrogen-Bond Donor Ability of Environmentally Friendly Anionic Reverse Micelles Explored by UV/Vis Absorption of a Molecular Probe and FTIR Spectroscopy
Girardi, Valeria R.,Silber, Juana J.,Falcone, Ruben Darío,Correa, N. Mariano
, p. 759 - 765 (2018)
In the present work we show how two biocompatible solvents, methyl laurate (ML) and isopropyl myristate (IPM), can be used as a less toxic alternative to replace the nonpolar component in a sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT) reverse micelles (RMs) formulation. In this sense, the micropolarity and the hydrogen-bond ability of the interface were monitored through the use of the solvatochromism of a molecular probe (1-methyl-8-oxyquinolinium betaine, QB) and Fourier transform infrared spectroscopy (FTIR). Our results demonstrate that the micropolarity sensed by QB in ML RMs is lower than in IPM RMs. Additionally, the water molecules form stronger H-bond interactions with the polar head of AOT in ML than in IPM. By FTIR was revealed that more water molecules interact with the interface in ML/AOT RMs. On the other hand, for AOT RMs generated in IPM, the weaker water–surfactant interaction allows the water molecules to establish hydrogen bonds with each other trending to bulk water more easily than in ML RMs, a consequence of the dissimilar penetration of nonpolar solvents into the interfacial region. The penetration process is strongly controlled by the polarity and viscosity of the external solvents. All of these results allow us to characterize these biocompatible systems, providing information about interfacial properties and how they can be altered by changing the external solvent. The ability of the nontoxic solvent to penetrate or not into the AOT interface produces a new interface with attractive properties.
Temperature programmed desorption studies of OD coadsorbed with H2 on Pt(111)
Backstrand, Kyle M.,Weibel, Michael A.,Moision, Robert M.,Curtiss, Thomas J.
, p. 7209 - 7218 (2000)
A molecular beam source of pure hydroxyl radicals has been developed and used to explore the water reaction catalyzed over Pt(111). An electrostatic hexapole selectively focused OD radicals from a supersonic corona discharge source onto a Pt target at a surface temperature of TS=143 K. Subsequent D2O temperature programmed desorption (TPD) spectra revealed two major features, one near TS ca. 170 K from desorption of molecular water overlayer and a second near TS ca. 210 K from the decomposition of an adsorbed OD intermediate. The latter feature was isolated and analysis of TPD spectra revealed that the D2O production reaction was approximately half-order in total oxygen coverage with a pre-exponential factor ranging from υd=4+/-1*1016 to 5+/-2*1018 molecules1/2 cm-1 s-1 and activation energy Ea=9.7+/-0.1 to 11.5+/-0.1 kcal mol-1 for initial coverage ranging from θ0=0.04 to 0.25 ML. Coadsorption studies of OD and H2 revealed that H atoms drive reactions with adsorbed OD at TS ca. 180 K to form all three water isotopes: D2O, HDO, and H2O. Oxygen (O2) TPD spectra contained three desorption features (TS=700 K, 735 K, and 790 K). The relative abundance of O2 from these three features was virtually the same in all low temperature (TS=143 K) TPD experiments. At elevated dosing temperatures (TS=223 K) the two features at TS=700 K and 790 K could be selectively titrated from the surface by hydrogen. The presence of hydrogen prior to OD exposure at this elevated temperature prevented the accumulation of oxygen on the surface. The implications of these observations on our mechanistic understanding of the low temperature (TS210K) water reaction are discussed.
Mechanism for the reaction of hydroxyl radicals with dimethyl disulfide
Butkovskaya,Setser
, p. 37 - 44 (1999)
Strong infrared chemiluminescence from the reactions of OH and OD radicals with CH3SSCH3 was observed in a discharge flow reactor viewed by a Fourier transform spectrometer. The recorded spectra were identical to the H2O and HDO plus D2O emission spectra from the OH+CH3SH and OD+CH3SD reactions, respectively. These observations strongly suggest that the primary reaction in the OH and OD+CH3SSCH3 system generates CH3SH and CH3SD molecules with the observed emission arising from the OH+CH3SH and OD+CH3SD secondary reactions.
