12037-06-8Relevant articles and documents
Lifetimes and quenching of B 2Σ+ PO by atmospheric gases
Wong, Koon Ng,Anderson, William R.,Kotlar, Anthony J.,DeWilde, Mark A.,Decker, Leon J.
, p. 81 - 90 (1986)
Pulsed laser excited fluorescence in the B 2Σ+->X2? system of gas phase PO was used to measure the lifetime for υ' = 0 of the B state.Rotationally resolved measurements for a few selected J' levels, at Ar or He carrier gas pressures of ca. 2 Torr, reveal no dependence of the lifetime on the rotational level excited.Earlier measurements of relative fluorescence intensities in the υ' = 0 vibrational progression were reinterpreted to extract the dependence of the electronic transition moment on internuclear distance.Using this transition moment, no lifetime dependence on rotational level is to be expected, even at low pressures.Rate constants for quenching of the B state PO by N2, O2, CO2, and H2O, and upper limits thereof for He and Ar are reported.O2 was found to react with ground state PO.A crude measurement of the rate constant was performed.The result is compared to two other known measurements.The rate constant is in excellent agreement with the previous measurement, but in poor agreement with that of a concurrent study.Further work is required to determine the reason for the discrepancy.A cathode ray-vidicon type waveform digitizer was found to lend itself readily to the lifetime measurements, wherein a low repetition rate laser was used.Unfortunately, it was discovered that small nonlinearities ( ca. 1 percent of full scale) in the digitizer response have a marked etfect on the fits to the exponential lifetime decays and, especially, the quenching rate constants.We believe this problem is not commonly recognized.A simple method for calibration of this type of digitizer and removal of these effects is presented.
The laser induced fluorescence spectrum and radiative lifetime of PO2
Hamilton, Peter A.
, p. 33 - 41 (1987)
The ultraviolet spectrum of PO2 first observed in absorption by Verma and McCarthy has been studied by laser induced fluorescence for the first time.The spectra are similar in many respects to those observed in the visible system of NO2 and no predissociation is observed.The loss of rotational structure is attributed instead to mixing with one or more near continuous background states, with the amount of mixing apparently related to excitation of the bending vibration.The radiative decays are observed to be nonexponential but are accurately described by a double exponential form.This gives collision free radiative lifetimes of about 0.5 and 4.5 μs for the structured and continuous states, respectively, with the effective lifetime of the structured state varying strongly with the amount of mixing.Collisional quenching rate constants are roughly constant at (6 +/- 1) * 10-10 and (4 +/- 1) * 10-11 cm3 molecule-1 s-1 for the two states, with the very rapid quenching rate of the structured state probably being for nonradiative transfer to the background continuum.From observations of the wavelength dependence of the fluorescence the ground state ν2 and ν1 frequencies are found to be about 387 and 1117 cm-1, respectively.The emission is very extensive and strongly red shifted and lends further evidence that these states of PO2 are responsible for the chemiluminescence observed in phosphorus/oxygen reactions.
A study of the products of the reaction of phosphorus and dioxygen
Bauschlicher Jr., Charles W.,Zhou, Mingfei,Andrews, Lester
, p. 3566 - 3571 (2007/10/03)
The products of the reaction of laser-ablated red phosphorus and dioxygen have been studied using experiment and theory. The bands at 480.3 and 1273.3 cm-1, previously attributed to PO3 in the matrix isolation IR experiments, are reassigned to PO3- Also observed in experiment are PO2, PO2-, P2O, OPOPO, P4, and higher oxides.
Infrared Spectra of O-Atom-PH3 Reaction Products Trapped in Solid Argon
Withnall, Robert,Andrews, Lester
, p. 4610 - 4619 (2007/10/02)
Argon/phosphine samples have been reacted with O atoms from a discharge, and the products trapped in solid argon for infrared spectroscopic analysis.Studies with isotopic precursors, stepwise photolysis, and sample annealing have made possible spectroscopic identification of PO, HPO, PO2, PO3, HOPO, P2O5, H2PO, and HPOH, the last five for the first time.The PO3 species appears to have D3h symmetry from the isotopic out-of-plane bending mode absorption.Molecular P2O5 is fromed on diffusion and reaction of PO2 and PO3.The major phosphine-oxygen atom reaction product H2PO photoisomerizes to HPOH.
