The effect of terminal substituents on the electronic properties of rod-shaped [HGaNH]_n oligomers

Abstract

The effect of electron-donating and electron-withdrawing terminal groups on the electronic structure of the rod-shaped X3[HGaNH]nY3 or needle-shaped XGa[HGaNH]nNY oligomers (X, Y = H, CH3, F, CF3; n = 9, 30 and 114) was computationally studied at the B3LYP/SVP level of density functional theory. While the needle-shaped oligomers exhibit moderate variability in the electronic structure upon changing the terminal substituents X and Y, the energy gap of long rod-shaped oligomers varies within 2 eV. For oligomers with n = 114, F3[HGaNH]n(CH3)3 exhibits the largest HOMO-LUMO gap of 2.91 eV, while (CH3)3[HGaNH]nF3 has the smallest gap of 0.94 eV.