Browsing by Author "Peng, Daoling"

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A nonlinear optical switch induced by an external electric field: inorganic alkaline-earth alkalide
(2019-05-28)
Li, Bo
;
Peng, Daoling
;
Gu, Feng Long
;
Zhu, Chaoyuan
;
應用化學系分子科學碩博班
Exploring a new type of nonlinear optical switch molecule with excess electron character is extremely important for promoting the application of excess electron compounds in the nonlinear optical (NLO) field. Here, we report external electric field (EEF) induced second-order NLO switch molecules of inorganic alkaline-earth alkalides, M(NH3) 6Na2 (M = Mg or Ca). The centrosymmetric structure of M(NH3) 6Na2 is destroyed in the presence of an EEF, and then a long-range charge transfer process occurs. It has been found that excess electrons are gradually transferred from one Na atom to the other Na atom through the inorganic metal cluster M(NH3) 6. Finally, the excess electrons are completely located on one of the two Na atoms. In particular, the electronic contribution of the static first hyperpolarizability (b e 0) for M(NH3) 6Na2 exhibits a large significant difference when the EEF is switched on. The b e 0 value of M(NH3) 6Na2 is 0 when EEF = 0, while the peak b e 0 values are 5.95 106 (a. u.) for Mg(NH3) 6Na2 (EEF = 58 10 4 (a. u.)) and 1.83 107 (a. u.) for Ca(NH3) 6Na2 (EEF = 53 10 4 (a. u.)). This work demonstrates that the compounds M(NH3) 6Na2 can serve as potential candidates for NLO switches.
Facially Polarized Molecule for Alkalides and Superalkalides with Considerable Nonlinear Optical Response
(2018-12-06)
Li, Bo
;
Peng, Daoling
;
Gu, Feng Long
;
Zhu, Chaoyuan
;
應用化學系
In this work, alkali M (Li and K) and superalkali M ' O-3 (M '=Li and Na) combined with facially polarized molecule, all-cis 1,2,3,4,5,6-Hexafluorocyclohexane (L, C6H6F6), were utilized to design novel alkalides L-M-L-M ' and superalkalides L-M-L-M ' O-3, respectively. Computational results show that alkalides L-M-L-M ' and superalkalides L-M-L-M ' O-3 have high thermodynamic stability, and the superalkalides L-M-L-M ' O-3 are more stable than the alkalides L-M-L-M '. Importantly, they also possess remarkable NLO responses, the electronic contribution of the static first hyperpolarizability (beta(e)(0)) has upped to 3.42x10(6) (a.u.) for L-K-L-Li3O. In particularly, the number of ligand L considerably impacts on beta(e)(0) value, namely, the beta(e)(0) value of Li-L-Li3O can be improved two orders of magnitude by adding additional ligand L, 1.31x10(6) (a.u.)(L-Li-L-Li3O) > 7.76x10(4) (a.u.)(Li-L-Li3O). We hope this work can attract researchers to design and synthesize novel excess electron compounds with high performance NLO materials.