scholarly journals Ozone Activation on TiO2 Studied by IR Spectroscopy and Quantum Chemistry

2021 ◽  
Vol 11 (16) ◽  
pp. 7683
Author(s):  
Timur Aminev ◽  
Irina Krauklis ◽  
Oleg Pestsov ◽  
Alexey Tsyganenko

The adsorption of different isotopic ozone mixtures on TiO2 at 77K was studied using FTIR spectroscopy and DFT calculations of cluster models. In addition to weakly bound ozone with band positions close to those of free or dissolved molecules, the spectrum of chemisorbed species was observed. The splitting of the ν1+3 combination band to eight maxima due to different isotopomers testified to the loss of molecule symmetry. The frequencies of all the isotopic modifications of the ozone molecules which form monodentate or bidentate complexes with four- or five-coordinated titanium atoms were calculated and compared with those of experimentally observed spectra. The four considered complexes adequately reproduced the splitting of the ν1+3 vibration band and the lowered anharmonism of chemisorbed O3. The energetically most favorable monodentate complex with four-coordinated titanium atoms showed good agreement with the observed spectra, although a large difference between the frequencies of ν1 and ν3 modes was found. For better coherence with the experiment, the interaction of the molecule with adjacent cations must be considered.

2008 ◽  
Vol 22 (4) ◽  
pp. 235-250 ◽  
Author(s):  
Alberto Mezzetti ◽  
Riccardo Spezia

We have used time-resolved step-scan FTIR spectroscopy to investigate the process of triplet formation in the peridinin–chlorophyll-a–protein (PCP) at 100 K. Results have led to the identification of possible marker bands for peridinin (Per) and3Per. Band assignment has been carried out performing a DFT investigation on Per,3Per and on model molecules. The main spectral feature is a couple of bands at 1746 (negative) and 1719 (positive) cm–1. The assignment of these two bands to the lactonic C═O of Per in (respectively) its fundamental S0 and tripletT1state is based on: (1) comparison with FTIR spectra of isolated Per in literature; (2) good agreement with DFT calculations for Per and3Per; (3) the downshift of the band upon triplet formation as predicted by DFT calculations in Per and similar lactonic systems; (4) the kinetic of band disappearance, in agreement with literature data. Another possible band for Per in its fundamental state has been identified at 1523 cm–1.The results are in overall agreement with a recent step-scan FTIR study on PCP at 298 K (Alexandre et al.,Biophys. J. 93 (2007), 2118–2128) even though some small discrepancies emerge, probably related to the different temperature at which experiments were carried out. Further DFT calculations have been performed to rationalise these spectral discrepancies. From a methodological point of view, the work demonstrates the potential of a combined step-scan FTIR/DFT approach in the study of photophysical processes in proteins. Furthermore, it has been shown that, when small differential IR signals are concerned, nagging photothermal effects can interfere and can possibly lead to misleading interpretations.


Author(s):  
Reynier Suardíaz ◽  
Emily Lythell ◽  
Philip Hinchliffe ◽  
Marc van der Kamp ◽  
James Spencer ◽  
...  

Elucidation of the catalytic reaction mechanism of MCR-1 enzyme, responsible for the antimicrobial resistance to colistin, using DFT calculations on cluster models.


ChemInform ◽  
2004 ◽  
Vol 35 (51) ◽  
Author(s):  
Olga V. Manoilova ◽  
Simon G. Podkolzin ◽  
Balarishna Tope ◽  
Johannes Lercher ◽  
Eric E. Stangland ◽  
...  

2015 ◽  
Vol 17 (38) ◽  
pp. 25014-25026 ◽  
Author(s):  
Fahri Alkan ◽  
C. Dybowski

Accurate computation of 207Pb magnetic shielding principal components is within the reach of quantum chemistry methods by employing relativistic ZORA/DFT and cluster models adapted from the bond valence model.


2018 ◽  
Vol 54 (4) ◽  
pp. 346-349 ◽  
Author(s):  
Michael Lesslie ◽  
Yang Yang ◽  
Allan J. Canty ◽  
Elettra Piacentino ◽  
Francis Berthias ◽  
...  

Isotope labelling, IR spectroscopy and DFT calculations reveal a novel ligand-induced decarbonylation reaction.


2012 ◽  
Vol 97 (7) ◽  
pp. 1043-1048 ◽  
Author(s):  
B. Wunder ◽  
S. Jahn ◽  
M. Koch-Muller ◽  
S. Speziale

2018 ◽  
Vol 122 (37) ◽  
pp. 8712-8717 ◽  
Author(s):  
Kenta Fujii ◽  
Michiru Sogawa ◽  
Nobuko Yoshimoto ◽  
Masayuki Morita

2006 ◽  
Vol 794 (1-3) ◽  
pp. 83-91 ◽  
Author(s):  
Jacek Żeglin´ski ◽  
Grzegorz P. Piotrowski ◽  
Ryszard Piękos´

1995 ◽  
Vol 414 ◽  
Author(s):  
J.-X Ciwen ◽  
J. A. Gardella ◽  
C. A. Santos ◽  
E. Mathiowitz

AbstractWe present in this paper the surface derivatization of polyanhydrides with triethylamine for labeling the hydroxyl group. The reaction was verified with diffuse reflectance FTIR spectroscopy. Surface derivatization of poly(fumaric-co-sebacic)anhydride of 50:50 and 20:80 compositions was performed and ESCA measurements showed the surface nitrogen concentration in good agreement with stoichiometry values.


2001 ◽  
Vol 105 (19) ◽  
pp. 4331-4336 ◽  
Author(s):  
Pierre M. Esteves ◽  
Alejandro Ramírez-Solís ◽  
Claudio J. A. Mota

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