title: Theoretical studies of the substitution patterns of boron-nitrogen (BN) fullerenes: from C50 up to C20B15N15 CBN ball.
abstract: Study on the patterns of successive BN pair substitution in C50 fullerene and the chemical and electronic properties of these substitutionally doped heterofullerenes has been carried out with semiempirical (AM1 and MNDO) and density functional (B3LYP/3-21G) theories. The BN units prefer to stay together following "single bond", "hexagon filling", and "continuity and equatorial belt" rules. The driving force governing the stabilities of these BN-doped fullerenes is the strain of the cage. Compared with C50, the redox activity of C50-2x(BN)x (x = 1-15) isomers decreases and becomes weaker by increasing the number of BN units, while the aromaticity of the C50-2x(BN)x derivatives decreases and is independent of the number of BN units but related to the substitution positions. The main infrared absorptions are similar for all the C50-2x(BN)x isomers and the infrared spectrum becomes simpler and stronger with increasing the number of BN groups.
authors.affiliation: Department of Chemistry, Nankai University, Tianjin, 300071, P. R. China. xxfang@nankai.edu.cn
authors.forename: Xiufang
authors.initials: X
authors.lastname: Xu
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Shang
authors.forename: Guichang
authors.initials: G
authors.lastname: Wang
authors.forename: Ruifang
authors.initials: R
authors.lastname: Li
authors.forename: Zunsheng
authors.initials: Z
authors.lastname: Cai
authors.forename: Xuezhuang
authors.initials: X
authors.lastname: Zhao