Effects of Electron Donor and Different Solvents on Polarizability and Second Hyperpolarizability of Diradical Complex Involving X(X=B,Al, Ga)

The polarizability(α) and second hyperpolarizability(γ) were systemically investigated for singlet diradical complex involving X(X=B, Al, Ga) atom. The results show that both the α and γ can be effectively tuned by varying the distance R(between compound A and a water molecule) and acceptor atom X. The lone pair of electrons from the O atom of the water molecule entered into the vacant p orbital of atom X, which increased the diradical character and led to the increase of the α and γ values. Furthermore, the polarizable continuum model(PCM) was used to test the effects of H₂O and CCl₄ solvents on the α and γ values. Both the α and γ values of the studied diradical complex 1a(1b, 1c) in H₂O and CCl₄ were uniformly enhanced. And the solvent effects of H₂O on either α or γ were larger than those of CCl₄.