The lithium-orientation effect on the hyperpolarizability in the short zigzag-edged monolithiated aza-M?bius graphene ribbon [2,7] isomers

摘要

In the short zigzag-edged aza-M?bius graphene ribbon [2,7], a Li atom monosubstitutes the end H atom from the knot subring (1) to the subring (7), respectively, seven structures of short monolithiated aza-M?bius graphene ribbon isomers [M?Li (1), M?Li (2), M?Li (3), M?Li (4), M?Li (5), M?Li (6), and M?Li (7)] with all the real frequencies are obtained at the B3LYP/6-31G (d) level. The results of the static first hyperpolarizabilities (β_0) show that lithiation effect on β_0 is obvious. The β_0 value of M?Li (4) (1019 a.u.) is about 4 times of 250 a.u. of the aza-M?bius graphene ribbon. For the lithiated M?bius isomers, the lithium-orientation effect is exhibited. The lithiated subring is or near the knot subring, the isomers [M?Li (1), M?Li (2), and M?Li (7)] have small β_0 values, while that is far away from the knot subring, the isomers [M?Li (4) and M?Li (5)] have large β_0 values. For the M?M (1) (M = Li, Na, and K), the alkali atomic number dependence for the static hyperpolarizability (α_0) and β_0 is found that both the α_0 and β_0 value increase with increasing the alkali atomic number in the orders of 275.27 (M = Li) < 279.75 (M = Na) < 284.77 a.u. and 352 (M = Li) < 590 (M = Na) < 706 a.u.