ESR of the P3− radical: establishment of the electronic ground state

The electron-spin-resonance (ESR) spectra of the P3− radical (D3h symmetry) in its X 3A2′ ground state have been observed in solid neon and argon matrices at 4 K. It is produced during laser-vaporization of solid GaP and is presumably the result of trapping the ionic GaP3 molecule. The analysis is in accord with earlier theoretical studies.