Matrix-Isolation Study of the Hydrogen Cyanide Dimer

Abstract

On the basis of the infrared spectra of HCN and DCN in Ar, N2, and CO matrices at temperatures from 4.5° to 20.5°K, it is concluded that there is no evidence for rotation of the monomeric species in these matrices and that the dimer has a linear or nearly linear HCN·HCN structure. The Lippincott-type potential is used to calculate frequencies for the stretching of the hydrogen bond and for the torsion about the hydrogen bond. These calculated frequencies are compared with our observed far-infrared spectra of dimers in the matrix and with available Raman data on crystalline HCN and DCN.

Ab initiostudies on structure, vibrational spectra and infrared intensities of HCN, (HCN)2and (HCN)3

“…Accurate vapour phase data are available for v2 [22,26], the hydrogen bonded C-H stretch, v a and v 4 [26], the C~N vibrations, v s [18], the intermolecular stretch and v9 [21], the lowest lying intermolecular bending vibration. Low temperature matrix isolation studies have scanned intramolecular stretching [28-31, 33, 34] and bending regions [28][29][30][31]. Far infrared investigations in different matrices on low lying intermolecular modes are also available [28,[32][33][34].…”

“…Low temperature matrix isolation studies have scanned intramolecular stretching [28-31, 33, 34] and bending regions [28][29][30][31]. Far infrared investigations in different matrices on low lying intermolecular modes are also available [28,[32][33][34]. The qualitative picture emerging both from SCF [42,43] and our CPF calculations agrees well with the experimentally observed trends in the vapour phase and by matrix spectroscopy as far as intramolecular modes are concerned (o91-o96)-The CPF results for o9s and o99 are also in close agreement with the gas phase data.…”

“…Microwave spectra of (HCN)3 are currently being studied [23]. Vibrational spectra of (HCN) 2 and of larger clusters have been investigated in the vapour phase and by matrix isolation spectroscopy [28][29][30][31][32][33][34]. The recent high resolution FTIR, PARS and CARS studies on (HCN)2 and (HCN)3 by Maroncelli et al 1,26,27] have allowed an approximate determination of infrared and Raman intensities in the region of C~-N vibrations.…”

Raman spectra of liquid and crystalline HCN and DCN

“…An infrared study of HCN and DCN isolated in various solid matrices has also been published (10). Our main purpose in undertaking the present study was to determine solid phases were consistent with the reported crystal structures.…”

Isocyano compounds newly recognized in photochemical reaction of thiazole: matrix-isolation FT-IR and theoretical studies

“…Several papers reported the bands of HC^N in the gas phase 30 and in the low-temperature matrices 23,[31][32][33][34] to be $3303 and $720 cm À1 for the C-H stretching and bending modes, respectively. The 3304 cm À1 and 715 cm À1 bands observed in Fig.…”