Synthesis, structures, and solid-state photoresponsive color change behavior of boronium complexes bearing a pyridine-imine, diimine, or pyridine-ketone bidentate ligand

Junro Yoshino; Yoshito Hirono; Ayako Kaneda; Naoto Hayashi

doi:10.1039/d3dt02332j

Synthesis, structures, and solid-state photoresponsive color change behavior of boronium complexes bearing a pyridine-imine, diimine, or pyridine-ketone bidentate ligand

Dalton Trans. 2023 Oct 24;52(41):15017-15022. doi: 10.1039/d3dt02332j.

Authors

Junro Yoshino^{1

2}, Yoshito Hirono², Ayako Kaneda², Naoto Hayashi^{1

2}

Affiliations

¹ Faculty of Science, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan. yoshino@sci.u-toyama.ac.jp.
² Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan.

PMID: 37812026
DOI: 10.1039/d3dt02332j

Abstract

9-Borabicyclo[3.3.1]nonane-based boronium triflates bearing a N-substituted 2-pyridylmethanimine, N,N'-dialkylethane-1,2-diimine, or 2-arylcarbonylpyridine ligand were synthesized. Their tetracoordinate boron structures were determined using ¹¹B NMR spectra and X-ray crystallography. The pyridine-imine complexes exhibited solid-state photoresponsive color changes upon UV irradiation, which indicated that boronium complexes without a bipyridine moiety also have photoresponsive capabilities. Combination of TD-DFT calculations and measurements of UV-vis absorption and fluorescence properties, diffuse reflectance spectra, and ESR spectra provided suggestions on the determining factor of the photoresponsive color change capabilities and structures of the photoproducts.