Lifetimes and quenching of B2Σ+ PO by atmospheric gases
摘要:
Pulsed laser excited fluorescence in the B 2Σ+ ← X 2π system of gas phase PO was used to measure the lifetime for v′=0 of the B state. Rotationally resolved measurements for a few selected J′ levels, at Ar or He carrier gas pressures of ∼2 Torr, reveal no dependence of the lifetime on the rotational level excited. Earlier measurements of relative fluorescence intensities in the v′=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 (∼1% of full scale) in the digitizer response have a marked effect 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.
Matrixreactions of P2 and isotopic ozone molecules have been studied using both heated GaP and discharge of P4 as sources of P2. Isotopic shifts and multiplets support identification of PO, PO2, P2O, P2O2, P2O3, P2O4, P2O5 and PO2− in these experiments.
A Study of the Products of the Reaction of Phosphorus and Dioxygen
作者:Charles W. Bauschlicher、Mingfei Zhou、Lester Andrews
DOI:10.1021/jp993623b
日期:2000.4.1
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-l, 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.
Detection of the infrared laser spectrum of the PO2 radical in the gas phase
作者:Hai-Bo Qian、Paul B. Davies、Imtiaz K. Ahmad、Peter A. Hamilton
DOI:10.1016/0009-2614(95)00128-q
日期:1995.3
The infrared laser absorption spectrum of the PO2 free radical has been detected in the reaction of oxygen atoms with white phosphorus. Over 300 lines of the ν3 fundamental band of the 2A1 ground state have been measured and assigned between 1300 and 1345 cm−1. Rotational, centrifugal distortion and spin-rotation constants for the ν3 = 1 level have been obtained from fitting the lines to an asymmetric
Infrared diode laser spectroscopy of the PO radical
作者:James E Butler、Kentarou Kawaguchi、Eizi Hirota
DOI:10.1016/0022-2852(83)90013-9
日期:1983.9
Abstract Vibration-rotation transitions of the PO radical in the X 2 Π r state have been observed by a tunable infrareddiodelaser spectrometer. The analysis of the observed spectra gave the molecular constants in the v = 1 state and the band origin to be B = 0.7250107(36), D = 1.0253(60) × 10 −4 , A J = 0.997(24) × 10 −4 , p = 0.006323(33), A 1 - A 0 = 0.16354(78), and ν 0 = 1220.24901(43), all in
摘要 PO 自由基在X 2 Π r 态的振动-旋转跃迁已被可调谐红外二极管激光光谱仪观测到。对观察到的光谱的分析给出了 v = 1 状态下的分子常数和带原点为 B = 0.7250107(36), D = 1.0253(60) × 10 -4 , AJ = 0.997(24) × 10 -4 , p = 0.006323(33), A 1 - A 0 = 0.16354(78), and ν 0 = 1220.24901(43),均以 cm -1 为单位,括号内为三个标准误差,其中 v = 0 参数固定为先前报告的值。平衡核间距离确定为 re = 1.476370(15) A 。
Kinetic studies of ground-state phosphorus atoms
作者:Michael A. A. Clyne、Yoko Ono
DOI:10.1039/f29827801149
日期:——
The kinetics of reactions (at 293 K) involving ground-state phosphorus atoms P(4S3/2) have been studied using resonance-fluorescence detection in a discharge–flow system for the first time. P atoms were formed by means of a discharge in helium with a trace of phosphorus trihalide. The rate constants k(cm3 molecule–1 s–1)(1σ) have been determined using pseudo-first-order kinetic analysis for the following
涉及基态磷原子P(4 S 3/2)的反应动力学(在293 K下)是首次在放电-流动系统中使用共振荧光检测进行了研究。通过氦气中微量三卤化磷的放电形成P原子。速率常数k(cm 3分子–1 s –1)(1σ)已通过以下一级反应的拟一级动力学分析确定:[图形省略] k的值与先前发表的研究。已经对导致差异的可能原因进行了调查。