Identification of a prismatic P<sub>3</sub>N<sub>3</sub> molecule formed from electron irradiated phosphine-nitrogen ices.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34526489.
- Also identified by DOI 10.1038/s41467-021-25775-1 and PMC identifier 8443655.
- Licence recorded as CC BY.
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Abstract
Polyhedral nitrogen containing molecules such as prismatic P<sub>3</sub>N<sub>3</sub> - a hitherto elusive isovalent species of prismane (C<sub>6</sub>H<sub>6</sub>) - have attracted particular attention from the theoretical, physical, and synthetic chemistry communities. Here we report on the preparation of prismatic P<sub>3</sub>N<sub>3</sub> [1,2,3-triaza-4,5,6-triphosphatetracyclo[2.2.0.0<sup>2,6</sup>.0<sup>3,5</sup>]hexane] by exposing phosphine (PH<sub>3</sub>) and nitrogen (N<sub>2</sub>) ice mixtures to energetic electrons. Prismatic P<sub>3</sub>N<sub>3</sub> was detected in the gas phase and discriminated from its isomers utilizing isomer selective, tunable soft photoionization reflectron time-of-flight mass spectrometry during sublimation of the ices along with an isomer-selective photochemical processing converting prismatic P<sub>3</sub>N<sub>3</sub> to 1,2,4-triaza-3,5,6-triphosphabicyclo[2.2.0]hexa-2,5-diene (P<sub>3</sub>N<sub>3</sub>). In prismatic P<sub>3</sub>N<sub>3</sub>, the P-P, P-N, and N-N bonds are lengthened compared to those in, e.g., diphosphine (P<sub>2</sub>H<sub>4</sub>), di-anthracene stabilized phosphorus mononitride (PN), and hydrazine (N<sub>2</sub>H<sub>4</sub>), by typically 0.03-0.10 Å. These findings advance our fundamental understanding of the chemical bonding of poly-nitrogen and poly-phosphorus systems and reveal a versatile pathway to produce exotic, ring-strained cage molecules.