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.