Intermolecular Dynamics and Exciplex Formation of van der Waals Complexes

1.在无碰撞条件下，研究了1-氰基萘/三乙胺范德华络合物在激发下的激基缔合物形成动力学。在VDW络合物的S_1态的分子内和分子间振动模之间的结合带的激发中发现了模式特异性，以促进激基络合物的形成反应。测量了S_1和激基络态的荧光衰减作为S_1起源以上过剩能量的函数。用一个简单的动力学模型讨论了观测到的衰变速率常数。在超音速膨胀条件下产生的范德华二聚体和9-乙基荧二聚体的激发下，得到了激基缔合物和激基缔合物的荧光光谱和衰减时间，激基缔合物的光谱最大值和衰变时间几乎介于荧烯和9-乙基荧准分子之间。VDW杂二聚体向激基复合体的转变发生在杂二聚体的激发态对应于9-乙基荧烯的局部激发态。在超音速自由喷流中观察到了1-氰基-4-甲基萘与三乙胺的两种范德华络合物。在这些络合物的天然起源带的激发下，其中一个络合物观察到分散的激基复合体荧光，而另一个络合物没有明显的激基复合体荧光。然而，荧光激发光谱表明，在激发到这些配合物的上振态的过程中，向激基络合物的转变进行了。这些喷射冷却物质的荧光衰减时间的测定也表明了VDW络合物的激基缔合物的形成。

1. The exciplex formation dynamics of the 1-cyanonaphthalene/triethylamine van der Waals complex upon excitation has been examined under collision free condition. Mode-specificity has been found in the excitation of a combination band between intra- and intermolecular vibrational modes in the S_1 state of the vdW complex to promote the exciplex formation reaction.The fluorescence decays of the S1 and exciplex states have been measured as a function of excess energy above the S1 origdn. The observed decay rate constants have been discussed using a simple kinetic model.2. Upon excitation of the van der Waals dimer and heterodimer of fluorene and 9-ethylfluorene generated in a supersonic expansion, the excimer and exciplex fluorescence spectra and decay times were obtained, The spectral maximum and decay time of the exciplex are almost intermediate between two excimers of fluorene and 9-ethylfluorene. The transformation of vdW heterodimer to the exciplex takes place from the excited state of the heterodimer corresponding to the locally excited state of 9-ethylfluorene.3. Two types of van der Waals complexes between 1-cyano-4-methylnaphthalene and triethylamine were obvserved in the supersonic free jet. Upon excitation of neraly origin bands of these complexes, the dispersed exciplex fluorescence was observed from one of the complexes, while no significnat exciplex fluorescence was detected from the other complex. However, the fluorescence excitation spectra demonstrate that the transformation to the exciplex proceeds in the excitation to the uper vibrational state of these complexes. The exciplex fromation from the vdW complex was also indicated by the determination of fluorescence decay times of these jet cooled species.