Lithium salt of end-substituted nanotube: Structure and large nonlinear optical property

Lithium salt of substituted nanotube is suggested as a new kind of nonlinear optical (NLO) material. It is found that the combination of the lithiation effect and the donor substitution effect can greatly enhance the static first hyperpolarizability (β0). Specially, the unusual donor – acceptor(nanotube) – donor system Li–NT(6,0)–(NH2)2 has considerable β0 to be 6.8 × 105 au, due to its small transition energy and large transition moment. Further, the relationships between β0 and the number of Li atoms m and the substituents R for Lim–NT(6,0)–(R)2 (m = 1, 6 and R = –CN, –NH2) systems are explored.