Infrared intensities of liquids. XVII. Infrared refractive indices from 8000 to 350 cm−1, absolute integrated absorption intensities, transition moments, and dipole moment derivatives of methan‐d3‐ol and methanol‐d4 at 25 °C

1994 ◽  
Vol 101 (10) ◽  
pp. 8364-8379 ◽  
Author(s):  
John E. Bertie ◽  
Shuliang L. Zhang
Keyword(s):  
Dipole Moment ◽  
Refractive Indices ◽  
Transition Moments ◽  
Infrared Intensities ◽  
Derivatives Of

Infrared Intensities of Liquids XV: Infrared Refractive Indices from 8000 to 350 cm−1, Absolute Integrated Intensities, Transition Moments, and Dipole Moment Derivatives of Methanol-d, at 25°C

1994 ◽  
Vol 48 (2) ◽  
pp. 176-189 ◽  
Author(s):  
John E. Bertie ◽  
Shuliang L. Zhang
Keyword(s):  
Refractive Index ◽  
Dipole Moment ◽  
Molecular Properties ◽  
Refractive Indices ◽  
The Real ◽  
Transition Moments ◽  
Refractive Index Spectrum ◽  
Integrated Intensities ◽  
Derivatives Of ◽  
Real Refractive Index

This paper reports infrared absorption intensities of liquid methanol- d, CH3OD, at 25°C, between 8000 and 350 cm−1 Measurements were made by multiple attenuated total reflection spectroscopy with the use of the CIRCLE cell, and by transmission spectroscopy with a variable-path-length cell with CaF2 windows. The results of these two methods agree excellently and were combined to yield an imaginary refractive index spectrum, k(ν˜) vs. ν˜, between 6187 and 350 cm−1. The imaginary refractive index spectrum was arbitrarily set to zero between 6187 and 8000 cm−1 where k is always less than 2 × 10−6, in order that the real refractive index can be calculated below 8000 cm−1 by Kramers-Krönig transformation. The results are reported as graphs and as tables of the real and imaginary refractive indices between 8000 and 350 cm−1, from which all other infrared properties of liquid methanol- d can be calculated. The accuracy is estimated to be ± 3% below 5900 cm−1 and ± 10% above 5900 cm−1 for the imaginary refractive index and better than ± 0.5% for the real refractive index. In order to obtain molecular information from the refractive indices, the spectrum of the imaginary polarizability multiplied by wavenumber, ν˜ vs. ν˜, was calculated under the assumption of the Lorentz local field. The area under this ν˜ spectrum was separated into the integrated intensities of different vibrations. Molecular properties were calculated from these integrated intensities—specifically, the transition moments and dipole moment derivatives of the molecules in the liquid, the latter under the harmonic approximation. The availability of the spectra of both CH3OH and CH3OD enables the integrated intensities and the molecular properties of the C-H, O-H, O-D, and C-O stretching and CH3 deformation vibrations to be determined with confidence to a few percent. Further work with isotopic molecules is needed to improve the reliability of the integrated intensities of the C-O-H(D) in-plane bending, H-C-O-H(D) torsion, and CH3 rocking vibrations.

Solvent effects on the infrared intensities of the ν2, ν4, and ν9 bands of 1,1-dichloroethylene

1987 ◽  
Vol 52 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Thomas Hensel ◽  
Johanna Fruwert ◽  
Klaus Dathe
Keyword(s):  
Dipole Moment ◽  
Field Effect ◽  
Interaction Model ◽  
Dipole Interaction ◽  
Statistical Correlation ◽  
Electric Polarizability ◽  
Normal Coordinates ◽  
Infrared Intensities ◽  
Local Field Effect ◽  
Derivatives Of

The infrared intensities of the ν2, ν4, and ν9 stretching bands of 1,1-dichloroethylene have been measured in eighteen solvents of different polarity. After correcting for the local field effect, the partial derivatives of the electric dipole moment and electric polarizability with respect to normal coordinates were calculated using the dipole-dipole interaction model. A good or a poor statistical correlation of the calculated and observed intensities then indicates whether this model is adequate or other phenomena are involved in the interaction.

Infrared Intensities of Liquids XI: Infrared Refractive Indices from 8000 to 2 cm−1, Absolute Integrated Intensities, and Dipole Moment Derivatives of Methanol at 25°C

1993 ◽  
Vol 47 (8) ◽  
pp. 1100-1114 ◽  
Author(s):  
John E. Bertie ◽  
Shuliang L. Zhang ◽  
Hans H. Eysel ◽  
Shipra Baluja ◽  
M. Khalique Ahmed
Keyword(s):  
Refractive Index ◽  
Dipole Moment ◽  
Attenuated Total Reflection ◽  
Refractive Indices ◽  
The Real ◽  
Molar Polarizability ◽  
Infrared Intensities ◽  
Integrated Intensities ◽  
Real Refractive Index ◽  
Better Than

This paper reports infrared absorption intensities of liquid methanol at 25°C between 8000 and 2 cm−1. Measurements were made by attenuated total reflection spectroscopy by four different workers between 1984 and 1991, with the use of CIRCLE cells of two different lengths and with several different alignments of the cell in the instrument. Steps were taken to ensure that as few parameters as possible remained unchanged throughout the series of measurements, to try to reveal systematic errors. The reproducibility was better than ±2.5% in regions of significant absorption. In order to allow comparison between different methods, results of all methods were converted to real and imaginary refractive index spectra. Measurements were also made by transmission spectroscopy in regions of weak absorption, with results that agreed excellently with those from ATR. The ATR and transmission results were combined to give a spectrum between 7500 and 350 cm−1. This spectrum agreed excellently with literature results from 350 to 2 cm−1, and the two sets of measurements were combined to yield a spectrum from 7500 to 2 cm−1. The imaginary refractive index was arbitrarily set to zero between 7500 and 8000 cm−1, where it is always less than 2 × 10−6, in order that the real refractive index can be calculated below 8000 cm−1 by Kramers-Kronig transform. The results are reported as graphs and as tables of the real and imaginary refractive indices between 8000 and 2 cm−1, from which all other infrared properties of liquid methanol can be calculated. The accuracy is estimated to be ±3% below 5000 cm−1 and ±10% above 5000 cm−1 for the imaginary refractive index and better than ±0.5% for the real refractive index. To obtain molecular information from the measurements, one calculates the imaginary molar polarizability spectrum, [Formula: see text] vs. [Formula: see text], under the Lorentz local field assumption, and the area under [Formula: see text] bands is separated into contributions from different vibrations under several approximations. Much accuracy is lost in this process. The changes of the dipole moment during normal vibrations, and during OH, CH, and CO bond stretching and COH torsional motion, are presented.

Optical Constants and Dipole Moment Derivatives of Bromobenzene between 3200 and 400 cm−1 at 25 °C

1998 ◽  
Vol 52 (8) ◽  
pp. 1062-1072 ◽  
Author(s):  
C. Dale Keefe ◽  
Janet Pittman
Keyword(s):  
Dipole Moment ◽  
Optical Constants ◽  
Refractive Indices ◽  
Normal Coordinates ◽  
Molar Polarizability ◽  
Ft Ir ◽  
Transmission Measurements ◽  
Integrated Intensities ◽  
Derivatives Of ◽  
Absorbance Spectra

The optical constants (real and imaginary refractive indices) of bromobenzene were determined at 25 °C via transmission measurements. Experimental absorbance spectra measured on a Nicolet Impact 410 FT-IR were converted to imaginary refractive indices by using methods described in the literature. The real refractive indices were obtained by Kramers-Kronig transformation of the imaginary refractive indices. The complex refractive indices were used to calculate the molar absorption coefficient ( Em) and complex molar polarizability (m) spectra. The integrated intensities and dipole moment derivatives with respect to normal coordinates for the fundamentals were obtained from the areas under the bands in the α“m spectrum. These dipole moment derivatives were compared to those obtained from the spectra of chlorobenzene in the literature. It was found that, in general, the dipole moment derivatives displayed very little dependence on the substituent, even for some of the vibrations for which the wavenumber is substituent sensitive.

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