Quantum Vibration Perturbation Approach with Poly-atomic Probe in Simulating Infrared Spectra

2021 ◽  
Author(s):  
Yang Cong ◽  
Yu Zhai ◽  
Jitai Yang ◽  
Adam Grofe ◽  
Jiali Gao ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Quantitative Prediction ◽  
Perturbation Approach ◽  
Atomic Probe

The quantitative prediction of vibrational spectra of chromophore molecules in solution is challenging and numerous methods have been developed. In this work, we present a quantum vibration perturbation (QVP) approach,...

VIBRATIONAL SPECTRA OF SOME ALKYLARSONIUM COMPOUNDS

1965 ◽  
Vol 43 (12) ◽  
pp. 3193-3200 ◽  
Author(s):  
W. R. Cullen ◽  
G. B. Deacon ◽  
J. H. S. Green
Keyword(s):  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Vibrational Assignments

The infrared spectra of some tetramethyl-, tetraethyl-, and triethylmethyl-arsonium salts, and that of tetramethylstibonium triiodomercurate(II) have been recorded in the region 4 000 to 200 cm−1. Vibrational assignments are given for the quarternary 'onium cations, and comparisons are made with the spectra of alkylorganometallic compounds of germanium and tin.

THE VIBRATIONAL SPECTRA OF THE FORMATE, ACETATE, AND OXALATE IONS

1956 ◽  
Vol 34 (2) ◽  
pp. 170-178 ◽  
Author(s):  
K. Ito ◽  
H. J. Bernstein
Keyword(s):  
Aqueous Solution ◽  
Raman Spectra ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Vibrational Assignments ◽  
Oxalate Ions ◽  
Oxalate Ion ◽  
Depolarization Ratios

The infrared spectra of the formate, acetate, and oxalate ions have been obtained for both the solid and aqueous solution. The Raman spectra of these ions with depolarization ratios have been obtained in aqueous solution. Vibrational assignments have been made which differ slightly for the acetate ion and more markedly for the oxalate ion from earlier work. The depolarization ratios confirm Fonteyne’s assignment for the formate ion.

scholarly journals Analysis of functional groups in atmospheric aerosols by infrared spectroscopy: sparse methods for statistical selection of relevant absorption bands

2016 ◽  
Vol 9 (7) ◽  
pp. 3429-3454 ◽  
Author(s):  
Satoshi Takahama ◽  
Giulia Ruggeri ◽  
Ann M. Dillner
Keyword(s):  
Infrared Spectra ◽  
Atmospheric Aerosols ◽  
Quantitative Prediction ◽  
Calibration Model ◽  
Vibrational Modes ◽  
Aerosol Composition ◽  
Absorption Bands ◽  
Calibration Models ◽  
Ft Ir ◽  
Selection Of

Abstract. Various vibrational modes present in molecular mixtures of laboratory and atmospheric aerosols give rise to complex Fourier transform infrared (FT-IR) absorption spectra. Such spectra can be chemically informative, but they often require sophisticated algorithms for quantitative characterization of aerosol composition. Naïve statistical calibration models developed for quantification employ the full suite of wavenumbers available from a set of spectra, leading to loss of mechanistic interpretation between chemical composition and the resulting changes in absorption patterns that underpin their predictive capability. Using sparse representations of the same set of spectra, alternative calibration models can be built in which only a select group of absorption bands are used to make quantitative prediction of various aerosol properties. Such models are desirable as they allow us to relate predicted properties to their underlying molecular structure. In this work, we present an evaluation of four algorithms for achieving sparsity in FT-IR spectroscopy calibration models. Sparse calibration models exclude unnecessary wavenumbers from infrared spectra during the model building process, permitting identification and evaluation of the most relevant vibrational modes of molecules in complex aerosol mixtures required to make quantitative predictions of various measures of aerosol composition. We study two types of models: one which predicts alcohol COH, carboxylic COH, alkane CH, and carbonyl CO functional group (FG) abundances in ambient samples based on laboratory calibration standards and another which predicts thermal optical reflectance (TOR) organic carbon (OC) and elemental carbon (EC) mass in new ambient samples by direct calibration of infrared spectra to a set of ambient samples reserved for calibration. We describe the development and selection of each calibration model and evaluate the effect of sparsity on prediction performance. Finally, we ascribe interpretation to absorption bands used in quantitative prediction of FGs and TOR OC and EC concentrations.

The preparation and vibrational spectra of some phenylchlorostannates

1970 ◽  
Vol 48 (17) ◽  
pp. 2787-2790 ◽  
Author(s):  
I. Wharf ◽  
J. Z. Lobos ◽  
M. Onyszchuk
Keyword(s):  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Alkylammonium Salts

The preparations of tetra-alkylammonium salts of the [(C6H5)2SnCl3]−, [(C6H5)2SnCl4]2−, and [(C6H5)3SnCl2]− ions are described. Infrared spectra (1300–100 cm−1) and Raman (400–100 cm−1) spectra are reported and an assignment of the bands is made.

Vibrational spectra of alkylamino substituted phthalocyanine compounds: Density functional theory calculations

2018 ◽  
Vol 22 (09n10) ◽  
pp. 771-776 ◽  
Author(s):  
Xin Chen ◽  
Chiming Wang ◽  
Yuxiang Chen ◽  
Dongdong Qi ◽  
Jianzhuang Jiang
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Bond Order ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Molecular Orbitals ◽  
Functional Theory ◽  
Localized Molecular Orbitals ◽  
Theoretical Investigations

The infrared spectra of tetrakis(dibutylamino) phthalocyanine and octakis(dibutylamino) compounds were studied via theoretical investigations. The results reveal deep fusion of the peripheral alkylamino moieties with the phthalocyanine chromophore in the tetrakis(dibutylamino)- but not in the octakis(dibutylamino)-phthalocyanine compounds. The successive localized molecular orbitals (LMO) and bond order analyses give support for the infrared vibrational results.

The Preparation and Low-Frequency Vibrational Spectra of Some Copper(I) and Silver(I) Alkane- and Arene-monothiolate Complexes

1979 ◽  
Vol 32 (7) ◽  
pp. 1443 ◽  
Author(s):  
GA Bowmaker ◽  
L Tan
Keyword(s):  
Raman Spectra ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Low Frequency ◽  
Far Infrared ◽  
New Methods ◽  
Thiolate Complexes ◽  
New Compounds ◽  
First Time ◽  
Far Infrared Spectra

A number of different methods for preparing anionic Group 1B metal thiolate complexes have been investigated. The compounds [Me4N] [CU2(SMe)3] and [Et4N] [Ag5(SBut)6] are reported for the first time, and new methods for preparing the previously known compounds [Et4N] [Cu5(SBut)6], [Me4N]2 [CU5(SPh)7] and [Et4N]2 [Cu5(SPh)7] are described. The far-infrared spectra of the above compounds, and of CuSMe, CuSBut, AgSBut, [Me4N]2 [CU4(SPh)6] and [Me4N]2 [Ag5(SPh)7] have been obtained, and metal-sulfur stretching bands are assigned in the 150-350 cm-1 region. The low-frequency Raman spectra have also been obtained for some of these compounds. Possible structures for the new compounds are considered in the light of the low-frequency vibrational spectra.

Vibrational Spectra of Bis-(Monothioacetylacetonato) Ni(II)

1969 ◽  
Vol 23 (3) ◽  
pp. 224-229 ◽  
Author(s):  
Umesh Agarwala ◽  
P. Bhaskara Rao
Keyword(s):  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
The Other ◽  
Methyl Groups ◽  
Vibrational Modes ◽  
Normal Coordinate ◽  
Conjugated Systems

The infrared spectra of substituted acetylacetonates have been discussed in the light of normal coordinate analysis of bis-(monothioacetylacetonato) Ni(II) assuming methyl groups as point masses. The Urey-Bradley potential constants evaluated are found to be quite close to those of analogous systems studied earlier. The calculations show that each of the fundamental bands results from vibrational modes involving appreciable contributions from a number of bonds. The single major contribution from the stretching of C = S has been found in the 723 cm−1 band. This is in agreement with the other conjugated systems, like thioamides, studied earlier.

Multivariate Calibration of Infrared Spectra for Quantitative Analysis Using Designed Experiments

1988 ◽  
Vol 42 (5) ◽  
pp. 865-872 ◽  
Author(s):  
Frederick Cahn ◽  
Senja Compton
Keyword(s):  
Infrared Spectra ◽  
Multivariate Calibration ◽  
Principal Component Regression ◽  
Principal Component ◽  
Experimental System ◽  
Weight Fraction ◽  
Quantitative Prediction ◽  
Residual Spectrum ◽  
Lattice Design ◽  
Simplex Lattice

The principal component regression (PCR) and partial least-squares (PLS) methods are used to calibrate and validate models for quantitative prediction of the composition of mixtures from FT-IR spectra. An experimental system of two- and three-component mixtures of xylene isomers was sampled with the use of statistical experimental designs. For two-component mixtures, the prediction error of independent validation samples decreased with increasing numbers of design points in the calibration. Four design points were needed to achieve a prediction accuracy of 0.0013 weight fraction. For three-component mixtures, a Scheffé {3,3} simplex lattice design, which has ten design points, achieved an equivalent accuracy of 0.002 weight fraction. There was little difference in performance between PLS and PCR computations. The results demonstrate the application of statistical methodology to the calibration of infrared spectra and show the importance of including an adequate number of samples in the calibration. The F test on the residual spectrum is shown to be a valuable tool for the identification of spurious data.

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