Shestakov O, Gielen R, Setzer KD, Fink EH
Physikalische Chemie, Fachbereich 9, Bergische Universität-Gesamthochschule Wuppertal, Wuppertal, D-42097, Federal Republic of Germany
J Mol Spectrosc. 1998 Nov;192(1):139-147. doi: 10.1006/jmsp.1998.7590.
First gas phase spectra of the nitrogen monoiodide radical NI are reported. The b1Sigma+(b0(+)) left and right arrow X3Sigma-(X10(+), X21) transition of NI has been studied by laser-induced fluorescence measurements. Ground state NI radicals were generated in a fast-flow system by reaction of microwave-discharged nitrogen with iodine vapor. Vibrational levels v = 0, 1, and 2 of the b1Sigma+ state were excited with a pulsed dye laser. Rotational and vibrational constants of the X3Sigma- and b1Sigma+ states were deduced from analysis of high-resolution excitation spectra. Time-resolved measurements of the fluorescence decay and measurements of relative line and band intensities allowed determination of the radiative lifetime of the b state, of band transition probabilities, and of the ratio of transition moments µ0/µ1 for the b0(+) --> X10(+) and b0(+) --> X21 subtransitions. Comparison of calculated and experimental line intensities and FC factors shows that treatment of the X3Sigma- state in terms of a Hund's case (a) formalism is preferable to use of a case (c) formalism. Copyright 1998 Academic Press.
首次报道了一碘化氮自由基NI的气相光谱。通过激光诱导荧光测量研究了NI的b1Σ+(b0(+)) ←→ X3Σ-(X10(+), X21)跃迁。在快速流动系统中，通过微波放电的氮气与碘蒸气反应生成基态NI自由基。用脉冲染料激光激发b1Σ+态的v = 0、1和2振动能级。通过对高分辨率激发光谱的分析推导了X3Σ-和b1Σ+态的转动和振动常数。荧光衰减的时间分辨测量以及相对谱线和谱带强度的测量，使得能够确定b态的辐射寿命、谱带跃迁概率以及b0(+) → X10(+)和b0(+) → X21子跃迁的跃迁矩之比µ0/µ1。计算和实验谱线强度以及FC因子的比较表明，用洪德情况(a)形式来处理X3Σ-态比使用情况(c)形式更为合适。版权所有1998年，学术出版社。
