Matrix Effects in Matrix Isolation Infrared Spectroscopy

A major factor limiting extensive use of matrix isolation gas chromatography-Fourier transform infrared spectrometry is the incompatibility of matrix-isolated spectra with available vapor- or condensed-phase spectral data bases. Here, matrix and surface effects on matrix isolation infrared spectra of organic molecules are investigated. Use of xenon at −215°C (58 K) to obtain matrix isolation spectra that are similar to condensed-phase spectra is demonstrated. Finally, the effect of temperature on reflection-absorption infrared spectra of matrix-isolated molecules is discussed, and guidelines for obtaining and interpreting matrix isolation infrared spectra of gas chromatographic eluants using the existing condensed phase data bases are provided.

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Evaluation of Infrared Vapor-Phase Libraries for Matrix Isolation Spectral Searching

Applied Spectroscopy ◽

10.1366/0003702874448021 ◽

1987 ◽

Vol 41 (6) ◽

pp. 1052-1056 ◽

Cited By ~ 10

Author(s):

Michael L. Rogers ◽

Robert L. White

Keyword(s):

Vapor Phase ◽

Infrared Spectra ◽

Matrix Effects ◽

Structural Information ◽

Matrix Isolation ◽

Band Broadening ◽

Library Search ◽

Search Results ◽

Spectral Searching ◽

Phase Spectra

By broadening matrix isolation absorbance bands to match vapor-phase bandwidths, it is possible to employ vapor-phase libraries to provide structural information from matrix isolation infrared spectra. However, matrix effects cause frequency shifting and peak multiplicity in matrix isolation spectra which decrease correlation between matrix isolation and vapor-phase spectra. The effect of matrix effects on library search results is investigated. Of 40 matrix isolation spectra tested, 28 were identified by library search with the use of a band-broadening factor of 1.8.

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Examinations of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part XVI

Applied Spectroscopy ◽

10.1366/0003702894203895 ◽

1989 ◽

Vol 43 (6) ◽

pp. 1008-1016 ◽

Cited By ~ 8

Author(s):

W. M. Coleman ◽

Bert M. Gordon

Keyword(s):

Fourier Transform ◽

Ir Spectra ◽

Vapor Phase ◽

Infrared Spectra ◽

Condensed Phase ◽

Matrix Isolation ◽

Absorption Bands ◽

Argon Matrix ◽

The Matrix ◽

The Impact

Information concerning the matrix isolation Fourier transform infrared spectra of a series of alkanes, esters, lactones, lactams, phenols, alcohols, amides, alkenes, and ketones is presented. A comparison between the characteristics of the spectra in two matrices (argon and xenon) as well as in the absence of any matrix (bare gold disk) is drawn. The impact of these matrices on the characteristics of the IR spectra is compared with the impact observed when spectra are gathered in the vapor phase as well as the condensed phase/solid state. For the majority of compounds studied, the major absorption bands of each class of compound fall between higher values for the vapor phase and lower values for the condensed phase when either argon or xenon is used as the matrix gas. The few exceptions are discussed. The absorption bands found in the xenon matrix are usually at a lower energy than are comparable bands in the argon matrix. In most all cases, the values of absorptions for compounds on the bare disk were lower than the comparable values found in the argon matrix. These results represent the first extensive study at 10 K of the effect of different matrix gas hosts and document the proposal that preconceptions of noble gases as inert hosts for the examination of FT-IR spectra at low temperature are not valid.

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Systematic optimization of a fragment-based force field against experimental pure-liquid properties considering large compound families: Application to oxygen and nitrogen compounds.

Physical Chemistry Chemical Physics ◽

10.1039/d1cp02001c ◽

2021 ◽

Author(s):

Marina Pereira Oliveira ◽

Philippe Hunenberger

Keyword(s):

Force Field ◽

Condensed Phase ◽

Organic Molecules ◽

Nitrogen Compounds ◽

Pure Liquid ◽

Fragment Library ◽

Systematic Optimization ◽

Phase Data ◽

Force Field Parameters ◽

Large Compound

The CombiFF approach is a workflow for the automated refinement of force-field parameters against experimental condensed-phase data, considering entire classes of organic molecules constructed using a fragment library via combinatorial...

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The infrared spectra of rhenium and osmium oxide tetrachlorides in the gas phase, condensed phase, and in solution

Australian Journal of Chemistry ◽

10.1071/ch9720027 ◽

1972 ◽

Vol 25 (1) ◽

pp. 27 ◽

Cited By ~ 8

Author(s):

CG Barraclough ◽

DJ Kew

Keyword(s):

Absorption Band ◽

Gas Phase ◽

Diethyl Ether ◽

Infrared Spectra ◽

Condensed Phase ◽

Trigonal Bipyramidal ◽

Stretching Vibrations ◽

Osmium Oxide ◽

Phase Spectra

The infrared spectra of ReOCl4 and OsOCl4 have been measured in the gas phase, in the condensed phase, and in a variety of solvents. In the gas phase spectra the absorption band envelopes corresponding to the metal-oxygen stretching vibrations have been observed and the data are discussed in terms of possible square pyramidal or trigonal bipyramidal structures for the molecules. Evidence is presented showing that acetone and diethyl ether molecules will readily coordinate to these oxide tetrachlorides when dissolved in inert solvents. The effect of traces of water on the same solutions is also described and discussed. Both ReOCl4 and OsOCl4 react with the solvent if dissolved in acetone or diethyl ether and the possibility of the formation of the unknown oxide trichlorides is discussed.

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