Raman spectroscopy of matrix-isolated hydrogen: I. Influence of matrices on defects

Abstract

The hydrogen molecule is treated as a model substance for matrix-isolation effects. Raman investigations are made concerning the influence of matrix material on the various modes of hydrogen. The opposite interaction, how the defect influences modes of the matrix, is the object of the following paper.For the doublet in the vibrational range of hydrogen in rare-gas solids, an assignment to Ql(0) and Q2(l) is made and well substantiated. In addition to matrix-shift considerations, temperature influences, orrho-para investigations, and aggregation effects, different sites are observable in the nonspherical matrices, N2 and 0 2 , with a restriction of free rotation in nitrogen.La molCcule d'hydrogkne est traitCe comrne une substance modkle pour les effets d'isolation de matrice. Des etudes de spectroscopic Raman ont CtC faites concernant l'influence du matCriau matriciel sur les diffkrents modes de l'hydrogkne. L'interaction opposCe-l'influence des dCfauts sur les modes de la matrice-est traitCe dans I'article suivant. Pour le doublet dans le spectre vibrationnel de l'hydrogkne, une attribution a Q1(0) et Q l ( l ) est faite et bien prouvCe. En plus des considCrations de dCcalage matriciel, des influences de la temperature, des investigations ortho-para et des effets d'aggrkgation, diffkrents sites sont observables dans les matrices non spheriques, N2 et 02, avec une restriction de rotation libre dans l'azote.

Photolysis of HCOOH monomer and dimer in solid argon: Raman characterization of in situ formed molecular complexes

“…However, it should be noticed here that the frequency values observed in our spectra are by B2.5 (for ortho-H 2 ) and B3 cm À1 (for para-H 2 ) red shifted as compared with Alikhani et al50 or Bier et al49 results and even by ca. 9 [S 0 (1)] or ca.…”

“…On the basis of previous reports on H 2 trapped in Ar matrices [49][50][51][52] these bands can be assigned to the S 0 (1) (582.1 cm À1 ) and S 0 (0) (348.6/350.5 cm À1 ) rotational lines of ortho-H 2 and para-H 2 , respectively. However, it should be noticed here that the frequency values observed in our spectra are by B2.5 (for ortho-H 2 ) and B3 cm À1 (for para-H 2 ) red shifted as compared with Alikhani et al 50 or Bier et al 49 results and even by ca. 9 [S 0 (1)] or ca.…”

Raman spectroscopy and crystal-field split rotational states of photoproducts CO and H2 after dissociation of formaldehyde in solid argon

“…[36][37][38][39][40][41][42] The first recorded spectra were obtained by Prochaska 42 measured rotational transition frequencies at 356.5 cm −1 and 587.9 cm −1 . To our knowledge, the latter study is the latest Raman measurement on isolated hydrogen in solid argon.…”

Structure of quench condensed nH2–N2 binary alloys: isotope effect

“…Solid mixtures of hydrogen with rare gases have been extensively studied within different approaches, ranging from rare-gas diluted matrix-isolation systems [1][2][3][4][5][6][7][8] to high mutual concentrations investigated macroscopically [9][10][11][12][13][14][15][16] and to new stoichiometric compounds formed at very high pressures [17]. Of special interest is the recent high-resolution infrared study [18], in which precise microscopic results are compared with inferences drawn from macroscopic measurements.…”

“…The results obtained in those papers suggest that not only the behavior of the hydrogen molecules change when placed in the rare gas crystals but that heavy rare gas impurities affect the hydrogen matrix. Hydrogen-containing alloys with molecular alloy components like N 2 , CH 4 , etc. were less studied, in many cases as matrix isolated species.…”