4. CONCLUSIONS
To find new high-performance deep-UV NLO molecules, the superalkalis (OLi3, ONa3, and OK3) and graphynes (GY/GDY/GTY) were combined to design superalkali salts of graphynes with considerable nonlinear optical (NLO) properties. Besides, the dependence of first hyperpolarizability of the resulting compounds on superalkali atom and pore size of graphyne were explored. The superalkali-doped complexes have high structural stability, which can be reflected by large interaction energies between the superalkali and graphyne units, ranging from –34.97 to –61.15 kcal mol-1. The atomic charge and frontier molecular orbital studies reveal that these superalkali-doped complexes are superalkali salts of graphynes. The superalkali and (pore) size of the graphyne unit play extremely important roles in enhancingβ 0 values of the doped complexes. Based on the best match between size of superalkalis and pore size of graphynes, OLi3+@GTY exhibits the β 0 value (653420 au) of new record for atom/superatom doped graphynes. Besides, these molecules have a working waveband in the deep-ultraviolet region. Hence, these superalkali salts of graphynes are new deep-UV NLO molecules with large second order NLO response.
ACKNOWLEDGEMENTS
This work was supported by National Natural Science Foundation of China (21373131 and 21573089), Shanxi Province Science Foundation for Youths (201801D221066), and the 1331 Engineering of Shanxi Province.