Excited-state intramolecular proton transfer:: A survey of TDDFT and RI-CC2 excited-state potential energy surfaces
Excited-state intramolecular proton transfer:: A survey of TDDFT and RI-CC2 excited-state potential energy surfaces
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DOI：
10.1021/jp050288k
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发表时间：
2005-04-14
影响因子：
2.9
通讯作者：
Hättig, C
中科院分区：
文献类型：
--
作者：
Aquino, AJA;Lischka, H;Hättig, C
用TDDFT和RI-CC2方法计算了丙二醛、邻羟基苯甲醛、水杨酸、7-羟基-1-吲哚和2-(2‘-羟基苯基)苯并噻唑的激发态分子内质子转移。计算了npi*和pi pi*态的垂直激发能和绝热激发能。总体而言，我们发现RI-CC2和TDDFT方法都是描述ESIPT势能面的很好的候选方法。计算了两种激发态的质子转移(PT)曲线。对于pi pi*态，已经发现了一个基本上无势垒且非常浅的能量分布。对于npi*态，酮托最小值比pi pi*态更明显，并且根据情况，发现了从<；0.1 eV到0.5 eV的能垒。根据计算的PT曲线，我们得出结论，两个激发态之间将出现扩展的交叉区。
TDDFT and RI-CC2 calculations have been performed on the excited-state intramolecular proton transfer in malonaldehyde, o-hydroxybenzaldehyde, salicylic acid, 7-hydroxy-1-indanone, and 2-(2'-hydroxyphenyl)benzothiazole. Vertical and adiabatic excitation energies have been computed for the n pi* and pi pi* states. Overall, we have found that both RI-CC2 and TDDFT methods are good candidates for the description of ESIPT potential energy surfaces. Proton transfer (PT) curves have been computed for both excited states. An essentially barrierless and very shallow energy profile has been found for the pi pi* state. For the n pi* state the keto minimum is more pronounced than for the pi pi* state and, depending on the case, energy barriers ranging from values < 0.1 eV up to 0.5 eV were found. From the computed PT curves we conclude that extended crossing regions between the two excited states will occur.