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论文类型：期刊论文

发表时间：2010-08-28

发表刊物：PHYSICAL CHEMISTRY CHEMICAL PHYSICS

收录刊物：SCIE、PubMed

卷号：12

期号：32

页面范围：9445-9451

ISSN号：1463-9076

摘要：An intermolecular coexistent hydrogen bond and a dihydrogen bond of a novel phenol-H2O-diethylmethylsilane (DEMS) complex in the electronically excited states were studied using the time-dependent density functional theory (TDDFT) method. Frontier molecular orbitals analysis revealed that the S-2 state of the dihydrogen-bonded phenol-H2O-DEMS complex is a locally excited state in which only the phenol site is electronically excited. Upon electronic excitation, the O-H and H-Si vibrational modes are red shifted compared with those calculated for the ground state. The O-H and H-Si bonds involved in the dihydrogen bond O-H center dot center dot center dot H-Si and hydrogen bond O-H center dot center dot center dot O are longer in the S-2 state than in the ground state. The H center dot center dot center dot H and H center dot center dot center dot O distances significantly shorten in the S-2 state. Thus, both the intermolecular dihydrogen bond and the hydrogen bond of the phenol-H2O-DEMS complex are stronger in the electronically excited state than in the ground state. In addition, the hydrogen bonding is favorable for the formation of the intermolecular dihydrogen bond in the ground state. However, they are competitive with each other in the electronically excited state.