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论文类型：期刊论文

发表时间：2013-09-01

发表刊物：JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE

收录刊物：SCIE、EI、Scopus

卷号：10

期号：9

页面范围：2088-2093

ISSN号：1546-1955

关键字：TDDFT; Metal-Organic Frameworks; Hydrogen Bond; Luminescence

摘要：We have theoretically investigated two luminescent metal-organic frameworks, (a) [Zn(cin)(2)(L-1)]center dot H2O and (b) [Cd(cin)(2)(L-1)]center dot H2O, where cin = cinnamate anion and L-1 = 1,1'-(1,4-butanediyl)bis(2-methylbenzimidazole), and have explored their hydrogen bonding and luminescent properties using time-dependent density functional theory (TDDFT). The calculated excitation maxima are in good agreement with experimental results. By examining frontier molecular orbitals and electron configurations, we have found that the origin of luminescence is dominated by the ligand-to-ligand charge transfer (LLCT) transition. In addition, we investigated the excitation energy changes between the isolated monomers and the hydrogen-bonded complexes, and concluded that intermolecular hydrogen bonds in the S-1 states of the two polymers are all weakened compared with those in the ground states. Further observation revealed that the excited-state hydrogen bond weakening can enhance the radiative deactivation of the fluorescence. Accordingly, both of the coordination polymers a and b are promising as multifunctional luminescent materials.