Formation of phosphine imide (HN[double bond, length as m-dash]PH3) and its phosphinous amide (H2N-PH2) isomer.

We present the first formation of the previously elusive phosphine imide (HN[double bond, length as m-dash]PH3) along with its phosphinous amide (H2N-PH2) isomer via exposure of phosphine (PH3) and ammonia (NH3) ices to ionizing radiation. Our approach may be extended to prepare, separate, and detect highly reactive compounds such as intermediates of Wittig reactions.

Synthesis of the hitherto elusive formylphosphine (HCOPH2) in the interstellar medium - a molecule with an exotic phosphorus peptide bond.

The formylphosphine (HCOPH2) molecule was detected in the gas phase via isomer selective photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS). Synthesized in carbon monoxide (CO)-phosphine ices (PH3) exposed to ionizing radiation, the formation mechanism involves an initial phosphorus-hydrogen bond rupture in phosphine yielding the phosphino radical (PH2) along with atomic hydrogen, addition of the suprathermal hydrogen atom to carbon monoxide leading to the formyl radical (HCO), and recombination of both radicals to formylphosphine (HCOPH2). This molecule represents the isovalent counterpart of the ubiquitous interstellar formamide (HCONH2). This study provides a fundamental framework to explore the synthesis and stability of the simplest isovalent counterpart of interstellar formamide (HCONH2) and suggests that formylphosphine (HCOPH2) should be detectable in the interstellar medium eventually providing a missing link between phosphorus-bearing complex organic molecules detected in the interstellar medium and on comet 67P/Churyumov-Gerasimenko.