Vinyl cyanide (CH2CHCN) in interstellar space: potential spectral lines for its detection

Abstract

Vinyl cyanide is a molecule having planar geometry with electric dipole moment components, 3.821 and 0.687 . Thus, a -type transitions are very strong as compared to b -type transitions, and are considered in this investigation. The rotational levels for a -type transitions, may be divided into two distinct groups: one group having odd values of and the other having even values of . Using the known values of rotational and centrifugal distortion constant along with the electric dipole moment , we have calculated energies of lower 120 rotational levels, having energy up to 92 , for each group, and the probabilities for radiative transitions between the levels. These radiative transition probabilities in conjunction with the scaled values of collisional rate coefficients are used in the Sobolev Large Velocity Gradient analysis. Out of a large number of lines, we have selected the strongest ones. In the low lying levels, besides the 4 observed lines of CH 2 CHCN, we have discussed about 8 additional transitions, of which 2 showing the phenomenon of anomalous absorption and 6 showing emission feature are found. These lines may play important role for the search of vinyl cyanide in a cosmic object.

Reliable Gas Phase Reaction Rates at Affordable Cost by Means of the Parameter-Free JunChS-F12 Model Chemistry

“…Aminoacetonitrile (AN), also known as vinylcyanide, has been found in several regions of the ISM 93 and may be also the best candidate for the formation of cell-like membranes in Titan’s hydrocarbon-rich lakes and seas. 94 Among the possible formation routes of AN, we have considered the addition of CN radical to ethylene, since both species are present in the ISM and on Titan. From an experimental point of view, the reaction was found to be very fast, approaching the gas kinetics limit at very low and very high temperatures.…”

Unsaturated Dinitriles Formation Routes in Extraterrestrial Environments: A Combined Experimental and Theoretical Investigation of the Reaction between Cyano Radicals and Cyanoethene (C2H3CN)

“…Cyanoethene, C 2 H 3 CN, also commonly known as vinyl cyanide or acrylonitrile, with the IUPAC name being 2-propenenitrile, is the simplest olefinic nitrile and has quite large dipole moment components in the molecular plane of μ a = 3.821 D and μ b = 0.687 D . This has favored its detection in a variety of extraterrestrial environments through the identification of its transition lines in the microwave to THz frequency range with the support of laboratory data and calculations. − The first detection was achieved in Sagittarius B2 in 1975, and more recently toward the hot molecular core Sgr B2­(N) , in Orion-KL, in the TMC-1 dark cloud, and in the L1544 proto-typical prestellar core, as well as toward IRAS 16293-2422 and in the circumstellar envelope of the C-rich star IRC + 10216 …”

Reliable Gas Phase Reaction Rates at Affordable Cost by Means of the Parameter-Free junChS-F12 Model Chemistry

“…Aminoacetonitrile (AN), also known as vinylcyanide, has been found in several regions of the interstellar medium (ISM) 88 and may be also the best candidate for the formation of celllike membranes in Titan's hydrocarbon-rich lakes and seas. 89 Among the possible formation routes of AN, we have considered the addition of CN radical to ethylene, since both species are present in the ISM and on Titan. From an experimental point of view, the reaction was found to be very fast, approaching the gas kinetics limit at very low and very high temperatures.…”