A 1-hydroxy-2,3,1-benzodiazaborine-containing pi-conjugated system: Synthesis, optical properties and solvent-dependent response toward anions

作者：Satta Yusuke; Nishiyabu Ryuhei; James Tony D; Kubo Yuji^*

来源：Tetrahedron, 2017, 73(15): 2053-2061.

DOI：10.1016/j.tet.2017.02.050

• Azaborine
• 2,3,1-Benzodiazaborine
• 1,8-Naphthalimide
• Photophysical studies
• Anion sensing

Our interest in the functionalization of -OH-substituted azaborines prompted us to synthesize a 1-hydroxy-2,3,1-benzodiazaborine conjugated with 1,8-naphthalimide 1. Its fluorescence was dramatically affected by the nature of the solvent. In particular, the use of DMSO, which has a relatively high donor number (DN = 29.8), led to a remarkable decrease in the fluorescence intensity (Phi(F) = 0.0014), possibly due to intermolecular hydrogen-bonding interactions (Me2S=O...HO-B). The presence of the hydroxyl group on boron led to a solvent-driven colorimetric response towards anions; high selectivity for F- over other anions in DMSO, and responded to AcO- and F- in THF, as shown by UV/vis titrations, NMR, and mass spectroscopic analysis. The nucleus-independent chemical shift (NICS) indices suggested that hydrogen bonding interactions between Me2S=O and HO-B reduced the aromaticity of the benzodiazaborine macrocycle, causing an increase in the negative character of the boron. The increase in the polarity of the B-N bond may prevent acetate-binding of 1 in DMSO.

• 出版日期2017-4-13