Synthesis of fully-fused bisboron azomethine complexes and their conjugated polymers with solid-state near-infrared emission

Abstract

We describe herein a robust π-conjugated molecules with solid-state emission in the near-infrared (NIR) region (ΦF = 0.03–0.06).

Vapochromic Luminescent π‐Conjugated Systems with Reversible Coordination‐Number Control of Hypervalent Tin(IV)‐Fused Azobenzene Complexes

“…[28][29][30] As examples, we discovered cubic silica and boron cluster compounds named polyhedral oligomeric silsesquioxane (POSS) [31,32] and ocarborane, [33,34] respectively, have been applicable to main scaffolds for creating functional materials showing superior luminescence behaviors with high durability or stimuli-responsiveness. We recently reported the series of solid-state luminescent complexes and polymers containing boron-fused azomethine (À C=NÀ ) [35][36][37][38][39] and azo (À N=NÀ ) [40][41][42][43][44] complexes with the tridentate ligands, o-salicylideneaminophenol or 2,2'-dihydroxyazobenzne scaffold, respectively. [45] These materials showed intense emission in the condensed state, and highlyefficient polymer film emission [38] and near-infrared (NIR) absorptive and emissive characteristics [40][41][42]44] were obtained.…”

The Design Strategy for an Aggregation- and Crystallization-Induced Emission-Active Molecule Based on the Introduction of Skeletal Distortion by Boron Complexation with a Tridentate Ligand

“…Indeed, the synthesized complexes have good solubility in common organic solvents such as chloroform, THF, and dichloromethane. The structures of BPhQ and BPhQm were confirmed by 1 H, 11 B, 13 C NMR, ionization mass measurements and elemental analyses. Fortunately, we obtained single crystals of the complexes suitable for X-ray analyses.…”

“…Figure S5: 11 B NMR spectrum of BPhQ, CDCl 3 , 128 MHz. Figure S6: 13 C NMR spectrum of BPhQ, CDCl 3 , 100 MHz. Scheme S4: Synthesis of BPhQm.…”

“…Figure S8: 11 B NMR spectrum of BPhQm, CDCl 3 , 128 MHz. Figure S9: 13 C NMR spectrum of BPhQm, CDCl 3 , 100 MHz. Table S1: Crystallographic data of BPhQ at 93 K. Table S2: Crystallographic data of BPhQm at 93 K. Figure S10: UV-vis absorption (left) and PL spectra (right) of BPhQ in the diluted solutions (1.0 × 10 −5 M) at room temperature.…”

“…In particular, boron-containing element-blocks are promising building blocks for obtaining luminescent materials. Boron-fused structures with bidentate π-conjugated ligands can enhance the rigidity and planarity of molecular frameworks because of their strong coordination ability originating from the electron-acceptor character of boron [12][13][14][15][16]. Thus, boron complexation is recognized as an established tactic for constructing highly-emissive fluorescent dyes [17][18][19][20][21][22][23][24].…”