Rotational dependence of the fluorescence quantum yields of H2CO and D2CO (quest;thinsp;1A2): single rovibronic level values and their average values for the 41level

摘要

The fluorescence quantum yields, Fgr;F(Kprime;,Jprime;), of single rovibronic levels (SRVLrsquo;s) of the 41(i.e., ngr;4prime;=1) vibrational state of H2CO and D2CO (quest;thinsp;1A2) have been measured at low pressures by laserhyphen;induced fluorescence using a multiple path cell. From these data, the rsquo;rsquo;absorption intensity weightedrsquo;rsquo; averages of Fgr;Fare obtained for severalKprime; rotational manifolds as Fgr;F(Kprime;) rang; and for the 41level as lang;Fgr;Frang;. The latter value of 0.031 confirms the validity of the SVL value of 0.0344 obtained from broadhyphen;band optical excitation by Miller and Lee. A random variation of Fgr;F(Kprime;,Jprime;) withJprime; is observed, and its implication to the question of radiationless transitions in formaldehyde molecules is discussed.