Knowledge Bank

Cyanophosphine, PH$2$CN (~{X}$\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$A), is the third row analog of cyanamide, a known interstellar molecule, and could be a potential interstellar species. However, only the microwave spectrum has been measured to date, and predictions at millimeter/submillimeter wavelengths have high uncertainities. Therefore, the millimeter/submillimeter spectrum of cyanophosphine has been measured using direct absorption techniques. This molecule was created by the reaction of gas-phase phosphorus, (CN)$2$, and H$2$ in the presence of argon carrier gas and an AC glow discharge. Eleven transitions have been recorded in the range 305-422 GHz each with multiple asymmetry components from K = 0 to 8. No evidence of inversion splitting was visible in the spectrum. The data have been fit with an asymmetric top Hamiltonian, and the spectroscopic constants have been determined. The A rotational constant and several higher-order centrifugal distortion parameters have been determined for the first time, allowing accurate predictions in the millimeter/submillimeter region. Here we report our laboratory measurements and an astronomical search.