14N-quadrupole coupling in the microwave spectrum of cyanamide, NH2CN

The microwave spectrum of cyanoformamide

“…For comparison, this table also includes the corresponding values obtained in the principle axis system of the molecules for propiolamide [12], cyanamide [15], acetylcyanide [16], and formamide [17]. The values for acetylcyanide are seen with hindsight to have presented a better starting point than cyanamide for the refinement of both v cy aa and v cy bb À v cy bb .…”

“…This latter criterion means that the number of identifiable component peaks, their relative intensity, and the splitting between them could be clearly related to one or the other of the four parameters to be determined, v cy aa and v cy bb À v cy cc , and v am aa and v am bb À v am cc , where the superscript indicates the cyanide or amide group. The simplest model system for starting values for the cyanide nitrogen nucleus was cyanamide, with a cyanide group directly on the a principle axis [15]. The structure of cyanoformamide gives a tilt of the nitrogen quadrupole environment relative to the a axis, but the projection on the a axis should still predominate.…”

Analysis of the mm- and submm-wave rotational spectra of isotopic cyanamide: New isotopologues and molecular geometry

“…This molecule has not yet been subjected to a systematic astrophysical investigation, but coincidences with predicted cyanamide lines are regularly noted in astrophysical surveys [15][16][17]. The rotational constants of cyanamide are rather high so that the ground-breaking work on its rotational spectrum was limited to the lowest-J rotational transitions in the cm-wave region [1][2][3][4]. Extension of these studies to the mm-wave region was made in [5][6][7][8][9], although the most extensive set of spectroscopic constants for the parent H 2 NCN species was determined in the study of its far infrared spectrum [12].…”

“…Like the ammonia molecule, it has been a prototype system for the study of the inversion motion at the nitrogen atom, in this case in the framework of a highly prolate asymmetric top. The rotational spectrum of cyanamide has been studied on numerous occasions [1][2][3][4][5][6][7][8][9][10], as was its rotationally resolved infrared spectrum [11][12][13]. Cyanamide is also an astrophysically relevant molecule, with the first reported detection dating back to more than 35 years ago [14].…”

An investigation of the relative stabilities of the isomers of CF2N2: Comparison of ab initio and MNDO calculations

“…The energies recorded in Table I indicate that there are a number of differences in the ordering between the MNDO and the HF/3-21G calculations. The two approaches agree in the ordering of isomers (1) and (2). The HF/3-21G calculation a g r e e s w i t h M N D O i n placing isomers (3146) next in energy, but in the order (51, (31, (61, (4).…”