The infrared spectra of solid solutions. I. The infrared spectrum of a dilute solution of NO−3 in KBr at 4 K

1985 ◽  
Vol 83 (1) ◽  
pp. 448-449
Author(s):  
C. J. H. Schutte
Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 112
Author(s):  
Carlos Emiliano Buelna-Garcia ◽  
José Luis Cabellos ◽  
Jesus Manuel Quiroz-Castillo ◽  
Gerardo Martinez-Guajardo ◽  
Cesar Castillo-Quevedo ◽  
...  

The starting point to understanding cluster properties is the putative global minimum and all the nearby local energy minima; however, locating them is computationally expensive and difficult. The relative populations and spectroscopic properties that are a function of temperature can be approximately computed by employing statistical thermodynamics. Here, we investigate entropy-driven isomers distribution on Be6B11− clusters and the effect of temperature on their infrared spectroscopy and relative populations. We identify the vibration modes possessed by the cluster that significantly contribute to the zero-point energy. A couple of steps are considered for computing the temperature-dependent relative population: First, using a genetic algorithm coupled to density functional theory, we performed an extensive and systematic exploration of the potential/free energy surface of Be6B11− clusters to locate the putative global minimum and elucidate the low-energy structures. Second, the relative populations’ temperature effects are determined by considering the thermodynamic properties and Boltzmann factors. The temperature-dependent relative populations show that the entropies and temperature are essential for determining the global minimum. We compute the temperature-dependent total infrared spectra employing the Boltzmann factor weighted sums of each isomer’s infrared spectrum and find that at finite temperature, the total infrared spectrum is composed of an admixture of infrared spectra that corresponds to the spectra of the lowest-energy structure and its isomers located at higher energies. The methodology and results describe the thermal effects in the relative population and the infrared spectra.


1975 ◽  
Vol 53 (17) ◽  
pp. 2642-2645 ◽  
Author(s):  
John E. Bertie ◽  
Marco Solinas

The far infrared spectra of four isotopic modifications of the partially orientationally ordered clathrate hydrate hexamethylenetetramine hexahydrate at 95 K are reported. The spectra are assigned to absorption allowed under the diffraction factor group, and to disorder-allowed absorption, following the theory for absorption by translational vibrations in orientationally disordered solids. Three phases formed primarily by hydrogen-bonded water molecules are known to be significantly, but only partially, orientationally ordered, hexamethylenetetramine hexahydrate, ice V, and ice VI. Of these phases, only ice VI fails to show sharp absorption in its far infrared spectrum in addition to the broad, disorder-allowed absorption.


Author(s):  
Hung-Yang Jain ◽  
Chih-Tsun Yang ◽  
Li-Kang Chu

The infrared spectrum of the simplest geminal diol, methanediol or methylene glycol (CH2(OH)2), was successfully probed in the gaseous hydration of formaldehyde. The observed absorption bands coincided with the anharmonic...


1980 ◽  
Vol 33 (2) ◽  
pp. 279 ◽  
Author(s):  
FA Devillanova ◽  
G Verani

The substitution of sulfur with selenium in benzimidazole- (bnt), benzoxazole- (bot) and benzothiazole-2-thione (btt) has been used to locate the vibrations related to the >C=S group. The thioketone bnt behaves like imidazolidine-2-thione, since it gives typical >C=S absorptions below 700 cm-1, while btt, like thiazolidine-2-thione, also gives rise to >C=S absorptions around 1000 cm-1. In bot the selenation also affects the NH modes, thus producing differences in several ranges of the infrared spectrum. The S- and Se-methiodides and the complexes obtained from these ligands with CdCl2 have been prepared and their infrared spectra compared with the free ligands; but it proves difficult to choose the site of coordination.


1963 ◽  
Vol 19 (7) ◽  
pp. 1173-1177 ◽  
Author(s):  
Marilyn E. Jacox ◽  
Dolphus E. Milligan

1970 ◽  
Vol 48 (1) ◽  
pp. 75-79 ◽  
Author(s):  
J. B. Milne

Tetrakis(methyl cyanide) complexes of Cu(I), Cu(II), and Zn(II) fluorosulfates have been prepared by reactions of anhydrous Cu(II) and Zn(II) fluorosulfates in methyl cyanide. The infrared spectra indicate a strong interaction between the fluorosulfate anion and the complex Cu(II) and Zn(II) cations. Conductivity measurements in methyl cyanide show strong association between the fluorosulfate anion and the dipositive cations. The Cu(I) compound is completely dissociated in methyl cyanide and, according to the infrared spectrum, shows no strong interaction with fluorosulfate anion.


1972 ◽  
Vol 26 (5) ◽  
pp. 540-542 ◽  
Author(s):  
G. R. Burns ◽  
D. G. McGavin

Infrared and Raman spectra have been measured for spiropentane-H8. Raman spectra for the liquid have enabled the b1 species ring twist to be assigned. Previous assignments of this mode were based on calorimetric data and on the assignment of a band in the infrared spectrum to a combination band involving the ring twist mode. Infrared spectra of low temperature crystalline films have provided sufficient information that, when taken with the Raman data and gas phase infrared spectra, we have assignments for all of the fundamental modes.


1971 ◽  
Vol 49 (12) ◽  
pp. 2008-2013 ◽  
Author(s):  
C. Jolicoeur ◽  
Nguyen Dinh The ◽  
A. Cabana

The near-infrared spectrum of water at various temperatures and in aqueous solutions of Bu4NBr, [Formula: see text], and [Formula: see text] is studied in the region 0.8–1.2 µ. The spectra are recorded differentially with respect to water by varying the cell lengths as to take into account density changes or the volume occupied by the solutes. A simple analysis of these spectra illustrates the qualitative similarity between the effects of the Bu4N+ ion and that of a temperature decrement on the spectrum of water. On the other hand striking differences are observed in the differential spectra obtained with Bu4NBr and the phenyl substituted: salts. Further differences are exhibited in the relative solute-solvent interactions of [Formula: see text] and [Formula: see text].


1979 ◽  
Vol 33 (6) ◽  
pp. 551-555 ◽  
Author(s):  
Stoil Dirlikov ◽  
Jack L. Koenig

Fourier transform infrared spectrum of atactic poly(methyl methacrylate) (PMMA) is compared with that of atactic PMMA labeled with 18O in the ester groups. The results obtained define the assignment of the bands associated with vibrations of the ester groups of PMMA. Furthermore, the Fourier transform infrared spectroscopy provides a simple method for obtaining the spectra of “pure” derivatives containing 18O.


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