权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Dynamics of internal rotation related to the intramolecular charge-t transfer reactions

与分子内电荷转移反应相关的内旋转动力学

基本信息

批准号：
06453022
负责人：
KAJIMOTO Okitsugu
金额：
$ 5.25万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

The aim of this project is to determine the internal rotation potentials of the compounds capable of forming an intramolecular charge-transfer (CT) state and then to observe the dynamics of the CT state formation on the twisting reaction coordinate. The following topics have been extensively studied1. Determination of the potential energy surface of internal rotationThe potential energy surfaces for the internal rotation of 9,9'-bianthryl (BA) -rare gas and BA-Ar complexes were determined. In a He complex the small perturbation slightly splits the degenerate twisting levels whereas in Ar and O complexes the shape of the potential is drastically changed ; one well of the double well potential disappears.2. The time-resolved fluorescence of BA complexesThe BA-Ar complex only emits the fluorescence from the excited S_1 state whereas the BA-H_2 O complex gives the fluorescence from both the S_1 and the CT states. The time profile of the BA-Ar fluorescence was found to be independent of the … More wavelength observed, which probably indicated the rapid IVR within the time resolution of the detecting system. On the other hand, the time profile of the BA-H_2O complex showed the wavelength dependence ; at the excitation wavelength 375 nm), it decayd very rapidly within 10 ps whereas at 380nm it increased first and then decreased with the time constant of 20 ps. The CT fluorescence increased with 20 ps rise time. This behavior indicates the presence of the intermediate state which probably be assignable to the vibarationally hot CT state3. The observation of the relaxation processes with the time-resolved fluorescence depletion (TRFD) methodWith the TRFD method, the rapid dephasing processes of the excited state of BA-Ar and BA-H_2O complexes have been observed. In the BA-Ar complexes, the observed dephasing of 10 ps corresponded to the intramolecular vibrational energy redistribution whereas in BA-H_2O complexes the observed 6 ps dephasing time could be attributed to both the IVR and CT state formation.4. A simulation of the dynamic processesThe simultaneously occurring IVR and CT state formation in the BA-H2O complexes was simulated in terms of the time-evolution of the wavefunction prepared by the ps excitation. The observed behavior was well reproduced. Less

本项目的目的是确定能够形成分子内电荷转移（CT）态的化合物的内部旋转势，然后观察CT态在扭转反应坐标上形成的动力学。以下主题已被广泛研究1。内旋位能面测定了9,9′-bianthryl (BA) -稀有气体配合物和BA- ar配合物的内旋位能面。在He络合物中，微小的扰动会轻微地分裂简并扭转能级，而在Ar和O络合物中，势的形状会发生剧烈的变化；双井电位中的一个井消失。BA配合物的时间分辨荧光BA- ar配合物只发出激发态S_1的荧光，而BA- h_2 - O配合物同时发出S_1和CT态的荧光。发现BA-Ar荧光的时间谱与观察到的波长无关，这可能表明在检测系统的时间分辨率内快速IVR。另一方面，BA-H_2O配合物的时间谱表现出波长依赖性；在激发波长375 nm处，在10ps内衰减非常快，而在380nm处，随时间常数20 ps先上升后下降，CT荧光随时间常数20 ps上升而增加。这种行为表明中间状态的存在，这可能是分配给振动热CT状态。用时间分辨荧光耗尽（TRFD）法观察了BA-Ar和BA-H_2O配合物激发态的快速消相过程。在BA-Ar配合物中，观察到的10 ps的失相时间对应于分子内振动能量的重新分配，而在BA-H_2O配合物中，观察到的6 ps的失相时间可归因于IVR和CT态的形成。动态过程的模拟根据ps激发制备的波函数的时间演化，模拟了BA-H2O配合物中同时发生的IVR和CT状态的形成。观察到的行为被很好地再现了。少