The infrared matrix isolation spectra of ND3 and NH3 in an argon matrix in the v2 bending region

1978 ◽  
Vol 31 (2) ◽  
pp. 247 ◽  
Author(s):  
JA Cugley ◽  
S Liberts ◽  
ADE Pullin
Keyword(s):  
Gas Phase ◽  
Matrix Isolation ◽  
Phase Model ◽  
Fundamental Region ◽  
Fractional Change ◽  
Argon Matrix ◽  
Rotational Constants ◽  
A Value ◽  
The Matrix

The spectra of NH3 and ND3 in an argon matrix have been obtained in the v2 (bending fundamental) region. The v2 region of ND3 has been interpreted in terms of a gas-phase model, with slightly altered rotational constants. Thus for the matrix an effective value of (B'+B') = 9.85 is required compared with 10.25 cm-1 for the gas phase. This represents a smaller fractional change than for NH3. The inversion splitting of ND3 in the argon matrix has been clearly resolved and a value of 2.0�0.1 cm-1 deduced. However, there are extra lines in the spectrum of ND3 which we cannot assign on the basis of a gas-phase model. For NH3 some vib-rotor 'lines' have been shown to be composite, in particular Q(11+) and Q(11-) are close triplets.

OPTICAL SPECTROSCOPY OF SIZE-SELECTED SILVER CLUSTERS EMBEDDED IN SOLID NEON: A CLUSTER-SUPPORT INTERACTION STUDY

1996 ◽  
Vol 03 (01) ◽  
pp. 1147-1152 ◽  
Author(s):  
W. HARBICH ◽  
Y. BELYAEV ◽  
R. KLEIBER ◽  
J. BUTTET
Keyword(s):  
Gas Phase ◽  
Silver Ions ◽  
Silver Clusters ◽  
Interaction Study ◽  
Quadrupole Mass ◽  
Mass Filter ◽  
Support Interaction ◽  
A Value ◽  
Sodium Clusters ◽  
The Matrix

Silver ions comprising 8, 11, 20, and 21 atoms have been produced by sputtering, mass-selected in a quadrupole mass filter and deposited at 30-eV landing energy together with neon on a 5-K sapphire support. The absorption spectra show results similar to the system Ag n / argon , but are better resolved. The spectra are compared to gas-phase depletion data and to corresponding sodium clusters. The matrix shift is analyzed and a value of the gas-phase position of the spectra is given.

An Accurate Quartic Force Field and Fundamental Frequencies for the Ozonide Anion: A Rare Positive Anharmonicity for the Antisymmetric Stretch

2003 ◽  
Vol 68 (1) ◽  
pp. 189-201 ◽  
Author(s):  
Timothy J. Lee ◽  
Christopher E. Dateo ◽  
Mercedes Rubio ◽  
Björn O. Roos
Keyword(s):  
Force Field ◽  
Gas Phase ◽  
Potential Surface ◽  
Matrix Isolation ◽  
External Environment ◽  
Theoretical Data ◽  
Antisymmetric Part ◽  
Fundamental Frequencies ◽  
The Matrix ◽  
Caspt2 Calculations

The CCSD(T) method has been used to compute a highly accurate quartic force field and fundamental frequencies for all 16O and 18O isotopomers of the ozonide anion. The CCSD and CASPT2 methods have also been used to verify the reliability of the CCSD(T) fundamental frequencies. The computed fundamental frequencies are in agreement with gas-phase experiments, but disagree with matrix isolation experiments for the antisymmetric stretch, ν3. CASPT2 calculations show that the antisymmetric part of the O3- potential surface is sensitive to the external environment. It is concluded that the antisymmetric stretch exhibits a significant matrix shift in the matrix isolation experiments and that the matrix environment is not representative of the gas-phase environment for ozonide anion. It is hoped that the theoretical data provided here will aid in the interpretation of future high-resolution gas-phase experiments.

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

1989 ◽  
Vol 43 (6) ◽  
pp. 1004-1008 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon
Keyword(s):  
Fourier Transform ◽  
Infrared Spectra ◽  
Matrix Isolation ◽  
Fourier Transform Infrared ◽  
Argon Matrix ◽  
Fourier Transform Infrared Spectra ◽  
The Matrix ◽  
Ft Ir ◽  
Oil Components ◽  
Search Routine

Matrix isolation Fourier transform infrared spectra (MI/FT-IR) of a series of essential oil components have been described. Clear, well-defined differences were detected in the MI/FT-IR spectra of compounds having minor differences in their structure. A library search routine was found to correctly identify components of interest when visual differences were not clearly evident. The presence of discrete conformers in the argon matrix resulted in the presence of split absorptions in the carbonyl band for selected compounds.

scholarly journals ИК спектроскопия высокого разрешения в низкотемпературных матрицах. Структура фундаментальных полос поглощения SiH-=SUB=-4-=/SUB=- в азотной и аргоновой матрицах

2020 ◽  
Vol 128 (10) ◽  
pp. 1478
Author(s):  
Р.Е. Асфин ◽  
М.В. Бутурлимова ◽  
Т.Д. Коломийцова ◽  
И.К. Тохадзе ◽  
К.Г. Тохадзе ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Temperature ◽  
Gas Phase ◽  
Experimental Conditions ◽  
Bending Vibration ◽  
Argon Matrix ◽  
Solid Nitrogen ◽  
The Matrix ◽  
Stretching Vibration ◽  
Narrow Bands

The features of high resolution IR spectra of the SiH4 molecule in N2 and Ar low-temperature matrices at 6.6-20 K were analyzed depending on experimental conditions. It was found, that in the nitrogen matrix in region of stretching vibration of 28SiH4 three narrow bands are observed, in the region of bending vibration (ν4) two bands are observed instead of one, which is explained by a change in the symmetry of the molecule from Td in the gas phase to C3v in solid nitrogen. In the argon matrix spectra change even more, where, in addition to narrow bands, the broad enough components are also recorded. The calculations of the SiH4 spectrum in the Ar matrix were performed based on the QM/MM approach, which confirm the reality of the change in the symmetry of the molecule as a result of its interaction with the matrix environment.

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

1989 ◽  
Vol 43 (6) ◽  
pp. 1008-1016 ◽  
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.

scholarly journals Structure and IR Spectra of 3(5)-Aminopyrazoles and UV-Induced Tautomerization in Argon Matrix

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4299
Author(s):  
Alina Secrieru ◽  
Susy Lopes ◽  
Maria L. S. Cristiano ◽  
Rui Fausto
Keyword(s):  
Ir Spectroscopy ◽  
Ir Spectra ◽  
Matrix Isolation ◽  
Energy Difference ◽  
Argon Matrix ◽  
Tautomeric Forms ◽  
Gibbs Free Energy Difference ◽  
The Matrix ◽  
Isolated Compound

The prototropic tautomerism in 3(5)-aminopyrazoles was investigated by matrix isolation infrared (IR) spectroscopy, supported by DFT(B3LYP)/6-311++G(d,p) calculations. In consonance with the experimental data, the calculations predict tautomer 3-aminopyrazole (3AP) to be more stable than the 5-aminopyrazole (5AP) tautomer (calculated energy difference: 10.7 kJ mol−1; Gibbs free energy difference: 9.8 kJ mol−1). The obtained matrix isolation IR spectra (in both argon and xenon matrices) were interpreted, and the observed bands were assigned to the tautomeric forms with help of vibrational calculations carried out at both harmonic and anharmonic levels. The matrix-isolated compound (in argon matrix) was then subjected to in situ broadband UV irradiation (λ > 235 nm), and the UV-induced transformations were followed by IR spectroscopy. Phototautomerization of the 3AP tautomer into the 5AP form was observed as the strongly prevalent reaction.

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

1988 ◽  
Vol 42 (2) ◽  
pp. 304-309 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon
Keyword(s):  
Fourier Transform ◽  
Organic Compounds ◽  
Vapor Phase ◽  
Infrared Spectra ◽  
Matrix Isolation ◽  
Fourier Transform Infrared ◽  
Argon Matrix ◽  
Fourier Transform Infrared Spectra ◽  
The Matrix ◽  
Ft Ir

Matrix isolation Fourier transform infrared (MI/FT-IR) data has been presented that documents the presence of discrete conformers in an argon matrix for a series of ketones. The distribution of conformers in the matrix was related to the structure of the molecule, in that rigid structures (i.e., small rings, bicyclic systems, and unsaturated systems) displayed simple carbonyl absorption patterns relative to those of their less rigid counterparts. Also, conformer isolation was seen for halosubstituted ketones. These results are in agreement with previous findings concerning the vapor-phase (VP) spectra of these molecules.

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