Vibrational Spectra and Rotational Isomerism in Acrylyl (Propenoyl) Chloride and Related α,β-Unsaturated Acyl Halides

Abstract

The complete vibrational spectra of acrylyl (propenoyl) chloride have been recorded and analyzed. This compound exists as a mixture of two discrete rotational isomers in the vapor and liquid states, their energy differing by about 0.6 kcal/mole in the vapor state. The spectra of the two isomers have been tentatively assigned and it has been found that all of the skeletal stretching modes are conformation dependent. Three other α,β-unsaturated acyl chlorides have been studied and the results are compared with those of acrylyl chloride.

Molecular and electronic structures of acryloyl isothiocyanate, CH2CHC(O)NCS: a joint experimental and theoretical study

“…The molecular structure and conformational properties of related CH 2 CHC(O)Cl and CH 3 C(O)NCS had been studied by theoretical and experimental methods. 35,38 The previous vibrational and theoretical investigations indicate that the trans conformation is preferred for acryloyl chloride and the trans-cis (F CQC-CQO = 1801, F OQC-NQC = 01) conformation is preferred for acryloyl isocyanate in the gas phase, 39 while substantial amounts of both conformers are present in the condensed phase. According to these antecedents, the structure of CH 2 CHC(O)NCS with both syn-periplanar orientations around the CC and CN single bonds was used as the initial form in the calculations.…”

Structure and Properties of Fumaryl Fluoride

“…In conjugated aldehydes, the energy difference between the two possible conformers is so high (>5.02 kJ · mol –1 ) that only a very small quantity of the second isomer is present at ambient temperatures. [ 16,17 ] In acrolein e.g., the configuration of the lowest energy is the trans ‐position [ 17,18 ] with an energy difference to the cis conformer of 6.99 kJ · mol –1 . [ 19 ] This is consistent with fumaraldehyde [ 11,20 ] existing only as its trans‐trans rotational isomer revealing an energy difference to the cis‐cis species of 13.50 kJ · mol –1 .…”

Infrared absorption of 3-propenonyl (⋅CH2CHCO) radical generated upon photolysis of acryloyl chloride [CH2CHC(O)Cl] in solid para-H2

“…5 Extensive experimental investigations on CH 2 CHC(O)Cl have been conducted. These include structural and spectral studies, [6][7][8][9][10][11] pyrolysis, 12 photolysis, [13][14][15][16][17][18] and photoionization. 19 Quantum-chemical calculations were also performed to predict the enthalpy, vibrational frequencies, electronic states, and reaction paths for isomerization and dissociation of CH 2 CHC(O)Cl.…”