Surface Oxidation of Au(111) Electrode in Alkaline Media Studied by Using X-ray Diffraction and Infrared Spectroscopy: Effect of Alkali Metal Cation on the Alcohol Oxidation Reactions

2015 ◽  
Vol 119 (41) ◽  
pp. 23586-23591 ◽  
Author(s):  
Masashi Nakamura ◽  
Yo Nakajima ◽  
Ken Kato ◽  
Osami Sakata ◽  
Nagahiro Hoshi
Keyword(s):  
Infrared Spectroscopy ◽  
Alkali Metal ◽  
Metal Cation ◽  
Alkali Metal Cation ◽  
Surface Oxidation ◽  
Alcohol Oxidation ◽  
Alkaline Media ◽  
Oxidation Reactions ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Alcohol Oxidation Assisted by Molybdenum Hydrazonato Catalysts Employing Hydroperoxide Oxidants

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 881
Author(s):  
Josipa Mihalinec ◽  
Matea Pajski ◽  
Pascal Guillo ◽  
Mirna Mandarić ◽  
Nikol Bebić ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Magnetic Resonance ◽  
Alcohol Oxidation ◽  
Polynuclear Complexes ◽  
Oxidation Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mononuclear Complexes

Molybdenum(VI) catalysts were obtained from methanol or acetonitrile by the reaction of [MoO2(C5H7O2)2] and isonicotinoyl- or nicotinoyl-based aroylhydrazones. Reactions in methanol resulted in the formation of the mononuclear complexes [MoO2(L1–4)(MeOH)] (1a–4a), while the ones in acetonitrile provided polynuclear complexes [MoO2(L1–4)]n (1–4). Crystals of polynuclear compound, [MoO2(L3)]n∙H2O (3∙H2O), suitable for X-ray diffraction analysis were obtained by the solvothermal procedure at 110 °C. Complexes were characterized by infrared spectroscopy (IR-ATR), nuclear magnetic resonance (NMR), elemental analysis (EA), and thermogravimetric analysis (TGA). The prepared catalysts were tested in alcohol oxidation reactions. Carveol, cyclohexanol, and butan-2-ol were investigated substrates. Because the alcohol oxidations are very challenging due to various possible pathways, the idea was to test different oxidants, H2O2, TBHP in water and decane, to optimize the researched catalytic system.

Synthèse et caractérisation des oxypentafluorouranates(VI) NH4UOF5, KUOF5, RbUOF5 et CsUOF5

1978 ◽  
Vol 56 (14) ◽  
pp. 1874-1880 ◽  
Author(s):  
Philippe Joubert ◽  
Roland Bougon ◽  
Bernard Gaudreau
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Alkali Metal ◽  
Vibrational Spectroscopy ◽  
Uranium Atom ◽  
The Other ◽  
Metal Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman And Infrared Spectroscopy

The oxypentafluorouranates(VI) MUOF5, where M = NH4, K, Rb, Cs, have been synthetized from reaction of UOF4 with the ammonium or corresponding alkali metal fluoride in liquid SO2. According to X-ray diffraction, Raman and infrared spectroscopy, and from an isomorphism with the corresponding hexafluorouranates(V) MUF6, two different environments around the uranium atom are observed. In CsUOF5 the five fluorine atoms and the oxygen around the uranium result in a pseudo-octahedral surrounding whereas for the other complexes (M = NH4, K, Rb) each uranium is surrounded by eight light atoms forming a dodecahedron. In this structure the dodecahedra are linked together by fluorine atoms to form infinite chains. The UOF5− ion has been characterized by vibrational spectroscopy in the solid state. The proposed assignment, which was made with the assumption of a C4v symmetry of the UOF5− ion, was confirmed by a force constant calculation. From these data and contrary to the values reported for comparable oxypentafluoroanions, the axial fluorine is found to be less ionic than the equatorial ones.

scholarly journals Investigation of the Effect of Nanocrystalline Calcium Carbonate-Substituted Hydroxyapatite and L-Lysine and L-Arginine Surface Interactions on the Molecular Properties of Dental Biomimetic Composites

Biomimetics ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 70
Author(s):  
Dmitry Goloshchapov ◽  
Vladimir Kashkarov ◽  
Kirill Nikitkov ◽  
Pavel Seredin
Keyword(s):  
Amino Acids ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Surface Interactions ◽  
Molecular Composition ◽  
Alkaline Media ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray

Differences in the surface interactions of non-stoichiometric nanocrystalline B-type carbonate-substituted hydroxyapatite (n-cHAp) with the amino acids L-Lysine hydrochloride (L-LysHCl) and L-Arginine hydrochloride (L-ArgHCl) in acidic and alkaline media were determined using structural and spectroscopic analysis methods. The obtained data confirm that hydroxyapatite synthesized using our technique, which was used to develop the n-cHAp/L-LysHCl and n-cHAp/L-ArgHCl composites, is nanocrystalline. Studies of molecular composition of the samples by Fourier transform infrared spectroscopy under the change in the charge state of L-Lysine in environments with different alkalinity are consistent with the results of X-ray diffraction analysis, as evidenced by the redistribution of the modes’ intensities in the spectra that is correlated with the side chains, i.e., amide and carboxyl groups, of the amino acid. During the formation of a biomimetic composite containing L-Lysine hydrochloride and n-cHAp, the interaction occurred through bonding of the L-Lysine side chain and the hydroxyl groups of hydroxyapatite, which created an anionic form of L-Lysine at pH ≤ 5. In contrast, in biocomposites based on L-Arginine and n-cHAp, the interaction only slightly depends on pH value, and it proceeds by molecular orientation mechanisms. The X-ray diffraction and infrared spectroscopy results confirm that changes in the molecular composition of n-cHAp/L-ArgHCl biomimetic composites are caused by the electrostatic interaction between the L-ArgHCl molecule and the carbonate-substituted calcium hydroxyapatite. In this case, the bond formation was detected by Fourier transform infrared (FTIR) spectroscopy; the vibrational modes attributed to the main carbon chain and the guanidine group of L-Arginine are shifted during the interaction. The discovered interaction mechanisms between nanocrystalline carbonate-substituted hydroxyapatite that has physicochemical properties characteristic of the apatite in human dental enamel and specific amino acids are important for selecting the formation conditions of biomimetic composites and their integration with the natural dental tissue.

Alkali Metal Cation Control of Oxidation Reactions of Radicals in Zeolites

1998 ◽  
Vol 120 (23) ◽  
pp. 5667-5673 ◽  
Author(s):  
Frances L. Cozens ◽  
Maria Luz Cano ◽  
Hermenegildo García ◽  
Norman P. Schepp
Keyword(s):  
Alkali Metal ◽  
Metal Cation ◽  
Alkali Metal Cation ◽  
Oxidation Reactions
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