Aggregation‐Induced Photoluminescent Changes of Naphthyridine–BF₂ Complexes

Abstract

Luminous boron: new 1,8-naphthyridine-BF(2) complexes with strong emissions both in solution and in the solid state have been developed. Aggregation-induced blueshifts of emissions in DMSO/water mixtures and solvent-influenced luminescence in crystalline states have been observed and are discussed.

Aggregation-induced emission enhancement (AIEE)-active boron-difluoride dyes with reversible mechanochromic fluorescence

“…For AIEE-active boron-diuoride dyes, non-pyrrolebased ligands with asymmetrical structures were normally adopted, such as b-diketone or N-substituted b-diketone derivatives, [14][15][16][17][18] b-iminoenolate derivatives [19][20][21][22][23][24][25][26][27] and others. [28][29][30][31][32][33][34][35] All these dyes bear rotatable bulky aromatic groups, which promotes the non-irradiative decay in dilute solutions. But in the solid state, the rotation was restricted, therefore, they emit low or no uorescence in dilute solutions but intense uorescence in the solid state.…”

Large Stokes Shift Induced by Intramolcular Charge Transfer in N,O-Chelated Naphthyridine–BF2 Complexes

“…For example, Piers et al explored high Stokes shift anilido-pyridine BF 2 dyes by harnessing a desymmetrized ligand to render the ground and excited states more energetically distinct. 9 One significant deficit in the properties of these dyes is their generally small Stokes shift. 4 A large pseudo-Stokes shift has also been realized by fluorescence resonance † Yunnan Normal University.…”

Solution‐ and Solid‐State Luminescent Borate Complexes Based on a Substituted π‐Conjugated 2‐(6′‐Hydroxy‐5′‐benzofuryl) Scaffold

“…The good planarity of the π‐conjugated scaffold combined with diminished π–π intermolecular interactions and enhanced Stokes' shifts (largely achieved by an unsymmetrical molecular structure) seem to be at the origin of a high solid‐state quantum yield. These trends have been confirmed in several other examples, including pyridomethene–BF 2 complexes,14 phenanthro[9,10‐ d ]imidazole‐quinoline–BF 2 dyes,15 naphthyridine–BF 2 16 or β‐iminoenamine–BF 2 17 complexes just to cite but a few. In all cases, the emission in the solid state is characterized by a modest‐to‐strong redshift compared with that in solution.…”