Infrared spectra of 2-pyridone-16O and 2-pyridone-18O

1968 ◽  
Vol 46 (15) ◽  
pp. 2475-2479 ◽  
Author(s):  
G. H. Keller ◽  
L. Bauer ◽  
C. L. Bell
Keyword(s):  
Absorption Band ◽  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Labelled Compound ◽  
High Concentrations

A comparison of the infrared spectra of natural 2-pyridone with that of the oxygen-18 labelled compound indicated modest shifts not only for the CO stretching mode (8.3−17.8 cm−1) for the various species in solution, but also for ring modes (0−13 cm−1) indicating a considerable mixing of the vibrations. The infrared spectrum of 2-pyridone at high concentrations revealed a new absorption band in chloroform solutions at 1685.0 and 1667.2 cm−1 for the unlabelled and labelled compound, respectively. In addition, absorption at 1614.9 cm−1 in the spectrum of 2-pyridone-18O in chloroform was found to be concentration dependent.

scholarly journals Exploration of Free Energy Surface and Thermal Effects on Relative Population and Infrared Spectrum of the Be6B11− Fluxional Cluster

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 ◽  
...  
Keyword(s):  
Free Energy ◽  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Thermal Effects ◽  
Global Minimum ◽  
Energy Surface ◽  
Weighted Sums ◽  
Free Energy Surface ◽  
Temperature Dependent ◽  
Relative Population

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.

The Far Infrared Spectra of Partially Orientationally Ordered Water Molecules: Hexamethylenetetramine Hexahydrate at 95 K

1975 ◽  
Vol 53 (17) ◽  
pp. 2642-2645 ◽  
Author(s):  
John E. Bertie ◽  
Marco Solinas
Keyword(s):  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Far Infrared ◽  
Clathrate Hydrate ◽  
Factor Group ◽  
Water Molecules ◽  
Disordered Solids ◽  
Ordered Water ◽  
Far Infrared Spectra ◽  
Three Phases

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.

Gaseous infrared spectra of the simplest geminal diol CH2(OH)2 and the isotopic analogues in the hydration of formaldehyde

2021 ◽  
Author(s):  
Hung-Yang Jain ◽  
Chih-Tsun Yang ◽  
Li-Kang Chu
Keyword(s):  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Absorption Bands ◽  
Geminal Diol

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...

The intensity of the absorption band in the infrared spectra of magnetized water and sodium oleate solutions

1970 ◽  
Vol 13 (4) ◽  
pp. 1332-1334
Author(s):  
M. A. Orel ◽  
I. V. Kagarlitskaya ◽  
I. V. Lapatukhin ◽  
R. A. Kabirova
Keyword(s):  
Absorption Band ◽  
Sodium Oleate ◽  
Infrared Spectra ◽  
Magnetized Water

'Selenation' as a diagnostic aid to reinvestigate the infrared spectra of benzimidazole-, benzoxazole- and benzothiazole-2-thiones

1980 ◽  
Vol 33 (2) ◽  
pp. 279 ◽  
Author(s):  
FA Devillanova ◽  
G Verani
Keyword(s):  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Diagnostic Aid

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.

Preparation and characterization of some methyl cyanide complexes of Cu(I), Cu(II), and Zn(II) fluorosulfates

1970 ◽  
Vol 48 (1) ◽  
pp. 75-79 ◽  
Author(s):  
J. B. Milne
Keyword(s):  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Strong Interaction ◽  
Strong Association ◽  
Conductivity Measurements ◽  
Methyl Cyanide ◽  
Cyanide Complexes

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.

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