title: DFT investigation on dihydrogen-bonded amine-borane complexes.
abstract: The DFT method has been employed in the exploration on dihydrogen-bonded amine-borane complexes, with a special emphasis on the dimerization and substituent group effect. Stable dihydrogen bonded complexes can be generated from these amine-borane monomers with the appearance of NH(δ+)…H(δ-)B interactions. The binding energy decreases gradually with the increase of the steric effect of the substituents. The substituent group number mainly varies the C-N bond length. The dimerization generates close H…H and influences predominantly the N-B distance. The effect of dimerization on IR and vibrational circular dichroism (VCD) spectra is stronger than that of the number of substituent groups, which leads to distinct NBO charge variation on α-C. Both the substituent group number and dimerization enhance the chemical shift difference between hydrogen atoms covalently bonded to N and B, Δδ H-H, which can be hired as an index for structural determination. It is proposed that amine-borane complexes with more substituent groups in higher degree of polymerization are potentially interesting materials for hydrogen storage. Graphical Abstract Both the number of substituent group and dimerization enhance the chemical shift difference of hydrogen atoms covalently bonded on N and B, Δδ H-H, which can be employed as an index for the structural determination.
authors.affiliation: College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, 266109, China. yansh@qibebt.ac.cn.
authors.forename: Shihai
authors.initials: S
authors.lastname: Yan
authors.affiliation: College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zou
authors.affiliation: College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, 266109, China.
authors.forename: Wukui
authors.initials: W
authors.lastname: Kang
authors.affiliation: College of Chemistry and Materials Science, Ludong University, Yantai, 264025, China.
authors.forename: Lixiang
authors.initials: L
authors.lastname: Sun
keywords: Amine-borane; Dihydrogen bond; Dimerization; NMR parameters; Substituent group