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Theoretical study on influence of ligand and solvent to CdS clusters
Author(s) -
Xu Shuhong,
Wang Chunlei,
Cui Yiping
Publication year - 2011
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.22427
Subject(s) - solvent , chemistry , absorption (acoustics) , raman spectroscopy , absorption spectroscopy , wurtzite crystal structure , nanocrystal , ligand (biochemistry) , wavelength , quantum dot , blueshift , spectral line , spectroscopy , aqueous solution , analytical chemistry (journal) , crystallography , zinc , photoluminescence , materials science , nanotechnology , optics , physics , organic chemistry , quantum mechanics , biochemistry , receptor , optoelectronics , astronomy , composite material
Based on the experimental zinc blende and wurtzite structures of CdS nanocrystals, five new CdS clusters (Cd 3 S 3 , (Cd 3 S 3 ) 2 , (Cd 3 S 3 ) 3 , Cd 4 S 4 with C 2V , and Cd 4 S 4 with T D symmetry) are investigated via optimization of their original structures at B3LYP/Lanl2dz theoretical level. Through considering integration influence of solvent and ligand, our calculated Raman and absorption spectra can be consistent with the reported experimental results. First, our calculated Raman peaks of Cd 3 S 3 , Cd 4 S 4 (T D ), (Cd 3 S 3 ) 2 , and (Cd 3 S 3 ) 3 are within the range of 260–290 cm −1 , which is also reported by experiment. Subsequently, for deep researching five clusters, the absorption spectra of them are calculated using time‐dependent DFT method. The wavelengths of the absorption peaks, which is calculated in solvent, increase in the order Cd 3 S 3 , Cd 4 S 4 (T D ), (Cd 3 S 3 ) 2 , and (Cd 3 S 3 ) 3 . Moreover, the wavelengths of absorption peaks shift to blue in solvent, compared with those without solvent. Furthermore, our clusters are smaller than the size of the smallest CdS nanocrystals, the calculated absorption spectra of five clusters in solvent show obvious blue shift than the wavelengths of absorption spectra of reported CdS nanocrystals. This is induced by the quantum size effect. Besides, we further investigated the influence of ligands to CdS unit in aqueous condition. Through structures and characters analysis of SCdSR, we discovered that ligands took important role during the formation of CdS nanocrystals in aqueous synthesis. Calculated results of spectra, bond length, and Wiberg bond index (WBI) values show that different ligands have similar influence on CdS unit. Moreover, using WBI values, we also confirm that Cd atom has stronger interaction with S in nanocrystals than that with S atom in ligand. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011