NH3(ν2) inversion doubling and two-mode interaction of PH3(ν4,ν2) in V–V energy transfer with

The collision induced deactivation constants of PH 2 ( X ˜ 2 B 1 ; v 2 ″ = 1 ) by H2S and NH3 have been determined. The NH3 constant appears to be anomalously high with respect to other polyatomic quenchers data in V–V energy transfer with PH 2 ( v 2 ″ = 1 ) . This deviation of the NH3 value has been ascribed to the inversion doubling of this molecule. The deactivation constant by PH3, determined in a previous work, has been re-examined. The removal of PH 2 ( v 2 ″ = 1 ) should be due to two PH3 vibrational modes, i.e., ν2 and ν4, and not to the single ν4, as formerly assumed, and their respective contributions have been estimated.