摘要
用双色双共振多光子电离光谱方法测量了NO分子A^(2∑+)(v=0)态的转动能量转移,得到了由R-F能量转移导致的转动可分辨的弛豫光谱,计算了转动态-态转移速率常数。用以转移能量为基础的指数和幂指数能隙模型,对碰撞弛豫态分布进行计算机模拟,并从计算值与实验值的比较讨论了能隙模型存在的不足。用同法对I_2分子B∏(O_u^+)态的测量,得到由转动能量转移导致的谱线展宽及交叠并作了分析。
Collision-induced rotational energy transfer in the A^2Σ^+(v = 0) state of NO has been measured by two-color double resonance-multiphoton ionization spectroscopy. Rotationally resolved relaxation spectra have been obtained for initial rotational levels N_i=1,7,13. The state-to-state rotational energy transfer rate constants have been determined from the experimental spectra by means of the rate equations under single collision approximation. The rate constant decreases with increasing rotational-quantum-number change ΔN. Exponential- and power-gap scaling laws have been used to analyze the experimental results and it has been found that the power-law fitting is better than the exponential-law fitting, especially for N_i=1. It has to be pointed out that the relaxation spectra from different initial rotational levels cannot be fitted well with a single set of parameters for either energy-based law.This result indicates that in addition to the energy gap some factors related to molecular rotation, e.g. the rotation period to the collision time ratio, must be taken into consideration in the collision model in order to describe the rotational energy transfer in detail. Similar rotational relaxation spectrum has been observed in NO-Xe (1:4) collision system. R-T energy transfer is considered to be the dominant pathway in collision-induced energy transfer between NO~* and NO molecules or between NO~* molecule and Xe atom. In addition, the rotation relaxation in the ΒΠ.(O_u^+) state of I_2 has been studied by OODR-MPI and the observed spectral line broadening discussed.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1991年第5期536-542,共7页
Acta Physico-Chimica Sinica
关键词
一氧化氮
碰撞诱导
转动能量转移
Two-color double resonance-multiphotion ionization spectroscopy, Collisioninduced rotational energy transfer
