Structures and electronic properties of lantern-like molecule BGe3H6N and its polymers

The structures, stability and electronic spectra of the lantern-like molecule BGe3H6N [1.1.1]propellane, and its polymers (BGe3H6N)n, H3N(BGe3H6N)nBH3 and OC(BGe3H6N)nAgCl (n = 1, 2, 3 and 4) have been investigated using density functional theory B3LYP method. Calculated results indicate that (BGe3H6N)n, H3N(BGe3H6N)nBH3 and OC(BGe3H6N)nAgCl (n = 1, 2, 3 and 4) are situated at the minima on the potential energy surfaces. With the increase of n, the vertical transition energies decrease from 264.2 to 4787.4 nm for (BGe3H6N)n, 391.7 to 619.4 nm for H3N(BGe3H6N)nBH3 and 432.3 to 2850.4 nm for OC(BGe3H6N)nAgCl, respectively. In addition, energy bands of [(BGe3X6N)2]n (X = H, F, Cl, Br and I) with one-dimensional periodic structures show that the direct-gap of [(BGe3X6N)2]n is the same to its indirect-gaps, which the band gaps are 2.67, 2.94, 2.80, 2.37 and 1.36 eV, respectively. Therefore, [(BGe3X6N)2]n (X = H, F, Cl, Br and I) with one-dimensional periodic structures might be promising direct-gap semiconductor materials.