Raman spectra of CN vibrations of acetonitrile in aqueous and other solutions. Experimental results andab initio calculations

The Raman spectra of oleums, i.e. mixtures of sulphur trioxide and sulphuric acid, have been re-examined. Similar measurements on the sulphur trioxide – deuterosulphuric acid (D2SO4) system are also reported. The experimental results and conclusions of previous similar work on oleums are discussed. By comparison of the spectra of oleums with those of the polysulphuryl halides it is shown that the polysulphuric acids H2S2O7 and H2S3O10 are present in this system. The increase in the frequency of the SO2 stretching vibrations with increasing concentration of sulphur trioxide gives evidence for the existence of higher polysulphuric acids such as H2S4O13 at high concentrations of sulphur trioxide. In relatively concentrated oleum, sulphur trioxide monomer and trimer are also present. It is shown that the self-dissociation of liquid H2S2O7 gives mainly molecular H2S2O10 and H2SO4 and not ionic species. The conclusions reached from the interpretation of the Raman spectra of the D2SO4–SO3 system are similar to those arrived at for sulphuric acid oleums. The spectra of solutions of NaHSO4 in oleums were also examined, and are discussed.

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Theory of Hydrogen Complexes in Si

MRS Proceedings ◽

10.1557/proc-209-391 ◽

1990 ◽

Vol 209 ◽

Author(s):

S. B. Zhang ◽

W. B. Jackson

Keyword(s):

Binding Energy ◽

Raman Spectra ◽

Experimental Results ◽

Lattice Expansion ◽

Strained Si ◽

Amorphous Si ◽

Gap States ◽

Hydrogenated Amorphous ◽

And Diffusion ◽

Strained Bonds

ABSTRACTThe predominance of Si-H bonding and the origin of {111} platelets in hydrogenated Si remain important unsolvedproblems in the study of H in Si.Recent theoretical and experimental results indicate that H predominately enters the Si network in pairs. A promising diatomic H configuration consists of a bond centered H closely associated with an antibonding centered H. In this work, we show that adjacent diatomic H pairs have a binding energy of 0.2 eV/2H. The binding originates from relaxation of strained Si-Si backbonds. Further clustering of the H pairs eliminates all strained bonds, forming a hydrogenated platelet oriented along the {111} plane. The binding energy of 3.95 eV/2H for the platelet is 0.15 eV lower than that for interstitial H2 molecules in c-Si. Lattice expansion makes the platelets energetically more competitivewith the lowest energy Si-H bonding confi gration at hydrogenated Si (111) surfaces. These higher level complexes explainthe formation of platelets, Raman spectra, and absence of gap states in hydrogenated c- Si as well as the clustered phaseseen in NMR and of H evolution and diffusion in hydrogenated amorphous Si.

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The interpretation of the infra-red and Raman spectra of the n -paraffins

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1954.0012 ◽

1954 ◽

Vol 247 (922) ◽

pp. 35-58 ◽

Cited By ~ 74

Keyword(s):

Raman Spectra ◽

Principal Series ◽

Experimental Results ◽

Absorption Bands ◽

Infra Red ◽

Complete Set ◽

Stretching Vibrations

Infra-red spectra of a series of crystalline n -paraffins containing an odd number of carbon atoms have been obtained. The spectrum of oriented crystals of n -nonadecane has also been examined. These new experimental results have been combined with the earlier data on the crystalline n -paraffins containing an even number of carbon atoms, and many series of absorption bands have been identified in the complete set of spectra. These regularities, as well as those present in the Raman spectra, have been interpreted in terms of CH 2 , CH 3 , and C—C stretching vibrations. Very regular distributions of frequencies have been found between 720 and 1030 cm -1 and between 1200 and ca. 1370 cm -1 , which are assigned to CH 2 rocking and wagging vibrations, respectively. The majority of the absorption bands between 1150 and 880 cm -1 can be attributed to C—C stretching or CH 3 rocking modes, and assignments are suggested for the principal series observed in this region.

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Photoelectrochemistry of Ferrites: Theoretical Predictions vs. Experimental Results

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2019-1449 ◽

2020 ◽

Vol 234 (4) ◽

pp. 719-776 ◽

Cited By ~ 3

Author(s):

Anna C. Ulpe ◽

Katharina C.L. Bauerfeind ◽

Luis I. Granone ◽

Arsou Arimi ◽

Lena Megatif ◽

...

Keyword(s):

Optical Absorption ◽

Electronic Properties ◽

Absorption Spectra ◽

Raman Spectra ◽

First Principles ◽

Experimental Results ◽

Atomic Scale ◽

Optical Absorption Spectra ◽

Photoelectrochemical Activity

AbstractThis paper gives an overview about recent theoretical and experimental work on electronic and optical properties of spinel ferrites MFe2O4. These compounds have come into focus of research due to their possible application as photocatalyst material for photoelectrochemical water splitting. The theoretical background of state-of-the-art quantum-chemical approaches applied for predicting electronic and optical band gaps, absolute band positions, optical absorption spectra, dielectric functions and Raman spectra, is briefly reviewed. Recent applications of first-principles methods on magnetic and electronic properties of ferrites with M = Mg and the first row of subgroup elements Sc to Zn are presented, where it is shown that the fundamental band gap is strongly dependent on the spin state and the degree of inversion of the spinel structure. The observed variation of electronic properties may serve as an explanation for the large scattering of experimental results. The exchange of M and Fe cations has also a pronounced effect on the Raman spectra of ferrites, which is analyzed at atomic scale from first principles. Calculated optical absorption spectra of ferrites are compared to experimental spectra. The electronic nature of the first excitations and the role of oxygen vacancies are discussed. For the calculation of absolute band positions, which have a significant impact on the photoelectrochemical activity of the ferrites, models of the most stable ferrite surfaces are developed that take into account their polar nature and the interaction with the solvent. Theoretically predicted valence and conduction band edges are compared to results from electrochemical measurements. The role of cation exchange on the surface electronic structure is investigated both theoretically and experimentally.

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Raman Spectra of Polyacrylonitrile

Applied Spectroscopy ◽

10.1366/000370271779951084 ◽

1971 ◽

Vol 25 (6) ◽

pp. 620-622 ◽

Cited By ~ 20

Author(s):

Y. S. Huang ◽

J. L. Koenig

Keyword(s):

Ir Spectra ◽

Raman Spectra ◽

Structural Models ◽

Experimental Results ◽

Planar Structure ◽

Selection Rules ◽

Polarized Raman

The polarized Raman spectra of polyacrylonitrile have been obtained and compared with ir spectra. On the basis of the selection rules, various proposed structural models are compared with the experimental results. The spectra suggest a syndiotactic rich composition with a planar structure. The blocks of syndiotactic placements are disrupted by short sequences of isotactic or atactic placements.

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Raman Microspectroscopic Study of the Cation Distribution in Amphiboles

Applied Spectroscopy ◽

10.1366/0003702884429490 ◽

1988 ◽

Vol 42 (8) ◽

pp. 1441-1450 ◽

Cited By ~ 16

Author(s):

A. Wang ◽

P. Dhamelincourt ◽

G. Turrell

Keyword(s):

Theoretical Analysis ◽

Raman Spectra ◽

Cation Distribution ◽

Raman Microspectroscopy ◽

Experimental Results ◽

Spectroscopic Methods ◽

Cation Distributions

The first attempt to determine the cation distributions in amphiboles by Raman microspectroscopy is described. The Raman spectra of five amphibole samples were obtained. It was observed that the Raman bands of the OH stretching modes were narrower than the corresponding infrared bands previously reported. However, even with the use of the most sophisticated Raman instruments, it was not possible to distinguish the bands due to the different cation arrangements of one particular configuration. Nevertheless, the experimental results and the theoretical analysis developed here allowed approximate calculations of the site occupancies to be made for four samples. These results yield a better understanding of the problems involved in the determination of the cation distributions in amphiboles with the use of vibrational spectroscopic methods.

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MO-theoretische Behandlung des F5SO--Ions und der korrespondierenden Saure F5SOH / The F5SO--Ion and the Corresponding Acid F5SOH

Zeitschrift für Naturforschung A ◽

10.1515/zna-1973-0924 ◽

1973 ◽

Vol 28 (9) ◽

pp. 1537-1538 ◽

Cited By ~ 3

Author(s):

Bernd M. Rode

Keyword(s):

Raman Spectra ◽

Experimental Results ◽

Ir And Raman Spectra ◽

Mo Calculations ◽

Related Compounds ◽

Ir And Raman ◽

Good Agreement

The bonding in the F5SO--ion is discussed by comparing the results of CNDO MO calculations on this and some related compounds with data obtained from IR- and RAMAN-spectra. Theoretical and experimental results are found to be in good agreement. The-yet not prepared -acid F5SOH is discussed with respect to its stabilization and acidity.

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Structure, isomerization and dimerization processes of narigenin flavonoids

Physical Chemistry Chemical Physics ◽

10.1039/d1cp01161h ◽

2021 ◽

Author(s):

Ana González Moreno ◽

Pilar Prieto ◽

M. Carmen Ruiz Delgado ◽

Eva Dominguez ◽

Antonio Heredia ◽

...

Keyword(s):

Molecular Structure ◽

Raman Spectra ◽

Experimental Results

In this study, theoretical and experimental results on molecular structure and reactivity of the plant flavonoids naringenin chalcone and naringenin are reported. UV-Vis and Raman spectra were recorded and their...

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Fragmentation of C60 Molecules in Partially Ionized Fullerene Beam Deposition

MRS Proceedings ◽

10.1557/proc-359-429 ◽

1994 ◽

Vol 359 ◽

Author(s):

Zhong-Min Ren ◽

Xia-Xing Xiong ◽

Yuan-Cheng Du ◽

Zhi-Feng Ying ◽

Liang-Yao Chen ◽

...

Keyword(s):

Raman Spectra ◽

Amorphous Carbon ◽

Experimental Results ◽

Cluster Beam ◽

X Ray Diffraction ◽

X Ray ◽

Partially Ionized ◽

Almost All ◽

Cluster Beam Deposition ◽

Beam Deposition

ABSTRACTC60 films have been deposited using a partially ionized cluster beam deposition (PIBD) technique. The experimental results show that as Va. exceeds about 400 V almost all the C60 molecules fragmentate at collision with the substrate and the obtained films turn to be amorphous carbon layers at elevated Va, indicated by measurements of Raman spectra, X-ray diffraction, and ellipsometry.

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Measurement of Nonuniform Stresses in Semiconductors by the Micro-Raman Method

MRS Proceedings ◽

10.1557/proc-505-507 ◽

1997 ◽

Vol 505 ◽

Cited By ~ 2

Author(s):

K. Pinardi ◽

S. C. Jain ◽

H. E. Maes ◽

R. Van Overstraeten ◽

M. Willander ◽

...

Keyword(s):

Absorption Coefficient ◽

Laser Beam ◽

Penetration Depth ◽

Raman Spectra ◽

Excellent Agreement ◽

Large Volume ◽

Strain Distribution ◽

Laser Light ◽

Experimental Results

ABSTRACTMicro-Raman measurements axe performed with a focused laser beam. Because of its finite diameter (∼ 1 μm) and penetration depth, the laser beam samples a “large volume” of the sample. In a nonuniformly strained sample, spectra originating from different points are different. Therefore the observed spectrum depends on both the strain distribution in the sample and the absorption coefficient of the laser light. We describe a method to calculate the Raman spectra taking these factors into account. The calculated spectra show excellent agreement with the experimental results.

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