Photoinduced reactions of chloroacetone in solid Ar: Identification of CH2=COCICH3

The UV light-induced reactions of chloroacetone in a cryogenic Ar matrix were investigated using infrared spectroscopy. The photoinduced isomerisations of gauche-chloroacetone to syn-chloroacetone and hypochlorous acid 1-methylethenyl ester were confirmed by comparing the experimental and calculated spectra. In addition, the photolysis products were found to be CH2double bond; length as m-dashCdouble bond; length as m-dashO and a cyclopropanone⋯HCl complex. The cyclopropanone⋯HCl complex was further decomposed into CH2double bond; length as m-dashCH2, CO and HCl. The hypochlorous acid 1-methylethenyl ester was further isomerized to 2-chloro-2-methyloxirane.ArticleCHEMICAL PHYSICS LETTERS. 614:258-262 (2014)journal articl

Density functional theory studies on the addition and abstraction reactions of OH radicals with terephthalate dianions

The addition and abstraction reactions of OH radicals with terephthalate dianions are investigated by density functional theory calculations that include solvent effects. Geometry optimizations of the reactants, products, and transition state species are performed for the potential reaction paths. For the addition reactions, those targeting the ipso- and ortho-carbons are predicted to be exoergic. The H-atom abstraction reaction is also predicted to be exoergic. On the basis of the rate constants calculated by means of the transition state theory, the H-atom abstraction reaction is determined to be the thermochemically favored path. (C) 2012 Wiley Periodicals, Inc.ArticleINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY. 113(4):418-422 (2013)journal articl

Computational study of the reaction between chloroacetone and OH radical

In this study, the reaction of the chloroacetone with OH radical was studied theoretically using density functional theory (DFT) and transition state theory. The potential energy surface of the reaction was calculated at the CAM-B3LYP/6-311++G(2d,2p) and M06-2X/6-311++G(2d,2p) levels. We initially considered four possible reaction paths: (1) the hydrogen atom abstraction from chloroacetone by OH radical; (2) the addition of the OH radical to the carbonyl carbon; (3) chlorine atom abstraction; and (4) SN2 displacement. The conventional transition state theory was employed to calculate the rate constants. The hydrogen abstraction from the ?CH2Cl group was found to be dominant. Since, the predicted total rate constant at the CAM-B3LYP/6-311++G(2d,2p) level was in good agreement with the experimental value at 298 K, the level of theory used in this study to describe this reaction is appropriate.ArticleCOMPUTATIONAL AND THEORETICAL CHEMISTRY. 1020:108-112 (2013)journal articl

Photoinduced rotamerization and dissociation of o-fluorobenzoyl chloride in solid Ar

UV light-induced reactions of o-fluorobenzoyl chloride (FBC) were investigated using infrared spectroscopy in a cryogenic Ar matrix. Photoinduced rotational isomerization from anti- to gauche-FBC was confirmed by comparison with calculated spectra. In addition, photolysis products were found to be ketene species (6-chloro-2-fluoro-2,4-cyclohexadien-1-ylidenemethanone), o-fluorobenzoyl radical, o-chlorofluorobenzene, m-chlorofluorobenzene and CO.ArticleCHEMICAL PHYSICS LETTERS. 613:34-39 (2014)journal articl

Matrix isolation studies of 185 nm light-induced cage reactions of o-chlorobenzaldehyde

VUV light photolysis of o-chlorobenzaldehyde (CBA) has been investigated by infrared spectroscopy in cryogenic Ar and O-2 matrices. Previously reported photoinduced rotational isomerization from anti- to syn-CBA was confirmed in the Ar matrix. In addition, absorption bands associated with photoinduced rearrangement to benzoyl chloride were observed accompanying the weak bands due to the CO photolysis product. However, in the reactive O-2 matrix, isomerization was observed and there was no evidence of benzoyl chloride formation. A kinetic analysis revealed that rearrangement was a minor process under the present excitation energy. The TD-B3LYP calculations show that as the excitation energy increases the predissociation channel will open and the repulsive (1)(pi, sigma(c-a)*) and 1(eta, sigma(c-a)*) states are directly achievable by the 185 nm excitation. Photoinduced rearrangement will be caused by the reaction of thus dissociated cage pairs.ArticleJOURNAL OF MOLECULAR STRUCTURE. 1025:48-52 (2012)journal articl

Influence of Dye Content on the Conduction Band Edge of Titania in the Steam-treated Dye-dispersing Titania Electrodes

The titania and dye-dispersing titania electrodes were prepared by a nitric acid-catalyzed sol-gel process. The dye-dispersing titania contains the dye molecules dispersed on the surface of the individual nanosized titania particles. The photo-cyclic voltammetry (Photo-CV) and photoelectric measurements of the dye-dispersing titania electrodes were conducted to clarify the factors changing the conduction band edge of the titania and the open-circuit voltage (V-oc) of the electrodes. The remaining nitrate ions caused a negative shift of conduction band edge of the titania of the dye-dispersing titania. The conduction band edge of the titania was shifted in a negative direction in the electrode containing a greater amount of the dye. These results are due to the adsorption of nitrate ions and the dye-titania complex formation on the titania particle surface. The effect of the dye-titania complex formation on the shift in the titania conduction band edge was greater than that of the adsorption of nitrate ions due to strong interaction between the dye and titania through the carboxylate and quinone-like groups of the dye. The shift in the titania conduction band edge corresponded to the change in the V-oc value.ArticlePHOTOCHEMISTRY AND PHOTOBIOLOGY. 90(5):1004-1011 (2014)journal articl

Removal of detergents and fats from waste water using allophane

Micelles, consisting of an anionic surfactant and a fatty acid released from fat, were removed from an aqueous phase using the ion exchange characteristics of a natural clay mineral, allophane. The UV spectral measurements revealed that the concentrations of the anionic surfactant and the fatty acid in the aqueous phase decreased and that these species were removed from the aqueous phase. The adsorption of the surfactant and the fatty acid onto the allophane was confirmed by FT-IR spectroscopy. Furthermore, this adsorption was confirmed by the adsorption of anthracene added as a probe molecule.ArticleAPPLIED CLAY SCIENCE. 47(3-4):325-329 (2010)journal articl

Global deceleration and inward movements of X-ray knots and rims of RCW 103

Kinematics of shocks, ejecta knots, and the compact remnant of a supernova remnant gives an insight into the nature of the progenitor and surrounding environment. We report on a proper motion measurement of X-ray knots and rims of the magnetar-hosting supernova remnant RCW 103. Chandra data obtained in three epochs, 1999, 2010, and 2016 are used. We find a global deceleration of 12 knots and rims both in northern and southern regions within the last $\sim 24$ yrs, even though its age is thought to be larger than 2 kyr. Some of them even changed their moving directions from outward ($\sim 1,000$ km s$^{-1}$) to inward ($\sim -2,000$ km s$^{-1}$). Our findings can be explained with a collision with a high-density medium both in the northern and southern edges of the remnant, although the remnant may still be expanding in the wind-blown cavity. The proper motion of the associated magnetar 1E161348$-$5055 is possibly detected with a velocity of $\approx 500$ km s$^{-1}$.Comment: 8 pages, 4 figures, accepted for publication in Ap