Kinetic study of the collisional quenching of electronically excited phosphorus atoms, P(32DJ, 32PJ), by polyatomic molecules

Abstract

Electronically excited phosphorus atoms, P(3²D_J) and P(3²P_J), respectively 1.40 and 2.32 eV above the P(3⁴S) ground state, have been generated by the pulsed irradiation of PCl₃. The optically metastable atoms have been monitored photoelectrically by atomic absorption spectroscopy using time-resolved attenuation of resonance radiation in the ultra-violet. The decay of the excited atoms has been investigated in the presence of a number of added gases and second order rate constants (300 K) for quenching of the two atomic states are reported for the following collision partners: HCl, Cl₂, CF₄, CF₃H, CF₃Cl, SF₆, C₂H₆, CH₃CHCH₂ and C₂H₂. The logarithms of the rate constants for the quenching of both P(3²D_J) and P(3²P_J) by polyatomic molecules were found to exhibit linear correlations with ionisation potential.