Fabrication of Optical Gap Selective Amorphous Carbon Photocatalyst for Hydrogen Production under Irradiation with Visible Light
K. Okafuji, R. Kobayashi, S. Ohtomo, H. Naragino, K. Honda
ECS Trans., 2017 75, 57-74.
DOI: 10.1149/07550.0057ecst

Abstruct: Diazulenylborinic acid 1 was synthesized by the reaction of 1,3-dibromoazulen-2-yllithium (2) with 1,3-dibromoazulen-2-ylboronic acid ethylene glycol ester (7d). The X-ray crystallographic study of 1 revealed that it forms a dimeric structure through intermolecular hydrogen bonding between the hydroxyl groups. To obtain the tetracoordinate borinate derivative from 1, the attempted esterification of 1 with N,N-dimethylethanolamine did not give corresponding borinate 8 but resulted in the unexpected protodeboronation to give parent 1,3-dibromoazulene (4). The 13C and 11B NMR studies of 1 in the presence of Et3N revealed the change in the π-polarization of the azulenyl group accompanied by the change in the geometry of the boron to a tetracoordinate structure.