Eighteen structures of new organic alkalides (M+@n 6adz)M′- (M, M′ = Li, Na, K; n = 2, 3) with the alkalimetal cation M+ lying near the center of the adz cage and the alkali-metal anion M′- located outside are obtained with all real frequencies. They exhibit very large static first hyperpolarizabilities (ß0) up to 3.2 × 105 au, which exceeds the record value of ß0 = 1.7 × 105 au for nonlinear optical compounds [Chem. - Eur. J. 1997, 3, 1091], All potassides (M+@n6adz)K- (M = Li, Na, K; n = 2, 3) have considerably large ß0 values (1.6 × 105-3.2 × 105 au) much larger than the ß0 value (3.6 × 104 au) of the previously designed cuplike alkalide Li +(calixpyrrole)K- [J. Am. Chem. Soc. 2006, 128, 1072]. This shows that the 26adz and 36adz cage complexants are preferable to cuplike calixpyrrole complexant in enhancing the first hyperpolarizability. The effect of cage size of the complexant on the first hyperpolarizability is also presented here: in most cases, the smaller cage complexant corresponds to the larger ß0 value. Moreover, the crucial role by the alkali-metal anion in the large first hyperpolarizability of these alkalides is revealed. These results may provide new means for designing high-performance nonlinear optical materials.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry