The lithium‐orientation effect on the hyperpolarizability in the short zigzag‐edged monolithiated aza‐Möbius graphene ribbon [2,7] isomers

Abstract

AbstractIn the short zigzag‐edged aza‐Möbius 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‐Möbius graphene ribbon isomers [MöLi (1), MöLi (2), MöLi (3), MöLi (4), MöLi (5), MöLi (6), and MöLi (7)] with all the real frequencies are obtained at the B3LYP/6‐31G (d) level. The results of the static first hyperpolarizabilities (β0) show that lithiation effect on β0 is obvious. The β0 value of MöLi (4) (1019 a.u.) is about 4 times of 250 a.u. of the aza‐Möbius graphene ribbon. For the lithiated Möbius isomers, the lithium‐orientation effect is exhibited. The lithiated subring is or near the knot subring, the isomers [MöLi (1), MöLi (2), and MöLi (7)] have small β0 values, while that is far away from the knot subring, the isomers [MöLi (4) and MöLi (5)] have large β0 values. For the MöM (1) (M = Li, Na, and K), the alkali atomic number dependence for the static hyperpolarizability (α0) and β0 is found that both the α0 and β0 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. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011