Infrared spectra and vibrational assignments of trans–CH3N–NH, CH3N–ND, CD3N–NH, and CD3N–ND

Abstract

Erratum: Infrared spectra and vibrational assignments of trans CH 3 N=NH, CH 3 N=ND, CD 3 N=NH , and CD 3 N=ND

Combined Electron-Diffraction, Spectroscopic, and Theoretical Determination of the Structure of N-Deuterio-trans-Methyldiazene, CH3N═ND. Conformational Effects of the N═N Double Bond

“…However, one would expect a large amplitude of motion for the methyl torsion, and this feature is borne out by the relatively large values of nonbonded H···N amplitudes in Table . The methyl torsional frequency itself has not been measured but is estimated to be about 170 cm –1 from combination bands seen for trans- CH 3 NNH . This value is in reasonable accord with harmonic/anharmonic values of 199/189 cm –1 that we calculate using the B3LYP method with a cc-pVTZ basis set.…”

“…The methyl torsional frequency itself has not been measured but is estimated to be about 170 cm −1 from combination bands seen for trans-CH 3 NNH. 24 This value is in reasonable accord with harmonic/anharmonic values of 199/189 cm −1 that we calculate using the B3LYP method with a cc-pVTZ basis set.…”

“…As nitrogen analogs to ethylene compounds, the diazenes are of considerable interest to chemists, both experimentally and theoretically. − The simplest of these are shown in Figure , with a trans arrangement displayed since in all cases this structure is theoretically lower in energy than the cis form. We note also that, for the trans forms, rotamers with a methyl CH bond eclipsing ( E ) the NN bond have a lower energy than the ones with staggered ( S ) CH bonds with respect to the NN bond.…”

“…22 Nonetheless, vibrational spectra of various deuterium isotopomers of both trans and cis forms have been reported. 17,23,24 No high-resolution vibration−rotation spectra have been recorded for either isomer, but some microwave rotational transitions have been measured for trans-CH 3 NND, which is more stable than its H counterpart. 25 The MW study yielded a dipole moment of 0.67(10) D 26 and accurate values for the rotational constants 25 B 0 and C 0 , respectively equal to 10254.50 (20) MHz and 9239.13 (20) MHz.…”

Synthesis and Vibrational Spectroscopy of 1,1,2,2-Tetrafluoroethane and Its 13C2 and d2 Isotopomers

“…A possible, but questionable, explanation is hydrogen bonding. In going from the gas phase to the crystal phase, one expects stretching modes to decrease in frequency and bending modes to increase in frequency with hydrogen bonding . In addition, although the shift due to hydrogen bonding should be smaller for CD bonds than for CH bonds, the difference observed for TFEA isotopomers is too large.…”