摘要
本文用(1+2+1)双共振多光子电离方法,以a^3A_2态的某一振转能级作为中间共振能级,从而克服自旋和对称性禁戒,首次在实验上观察到了H_2CO分子的一个三重Rydberg态~3A_2(n,3p_x)。另外,选择以A^1A_2态的某单振转能级为中间共振能级,到达了与上三重态对应的单重态~1A_2(n,3p_x)。对这两个态的振动光谱和部分可分辨的转动光谱分别进行了分析和归属。分析可知,~3A_2(n,3p_x)和~1A_2(n.3p_x)的带原点分别位于67809cm^(-1)和67400cm^(-1),且两态皆为非平面平衡构形。由部分可分辨的~3A_2(n.3p_x)4~2带的转动光谱分析,初步拟合得该态转动常数为A=9.40cm^(-1),B=0.96cm^(-1)。
The Rydberg states ~3A_2 (n,3p_x) and 'A_2 (n, 3p_x) of formaldehyde were studied by using (1+2+1) OODR REMPI: ions←^(1,3)A_2(n, 3p_x)←←A or a←X. This is the first experimental obser- vation of the formaldehyde ~3A_2 (n, 3p_x) state. The vibrational structure and partially resolved rotational structure of these two states have been obtained via selected vibration-rotational lev- els of A^(-1) A_2 state and a^(-3) A_2 state respectively as an intermediate resonance level. The origins of ~1A_2 (n, 3p_s) state and ~3A_2 (n, 3p_x) state are at 67809cm^(-1) and at 67400cm^(-1) respectively. Both states are nonplanar peometry. A preliminary assignment for ~3A_2 (n, 3p_x) 4~2 band rotatinal structure was given with the approximate rotational constants A = 9.40 cm^(-1) and B = 0.96cm^(1).
基金
国家自然科学基金~~
