D-A charge transfer, including through-bond charge transfer and through-space charge transfer between two different electron donors(D) and electron acceptors(A), is a fundamental and powerful tool to tune the optical ...D-A charge transfer, including through-bond charge transfer and through-space charge transfer between two different electron donors(D) and electron acceptors(A), is a fundamental and powerful tool to tune the optical properties of organic dyes. Herein,we demonstrate a unique strategy to tune phosphorescence and circularly polarized luminescence properties of axially chiral binuclear Pt(Ⅱ) complexes through long-range charge transfer, even though these molecules have two totally identical segments on either side of the chiral core. The presence of axial chirality would break not only the symmetry of molecular structure and π-conjugation system but also the symmetry of charge distribution for long-range charge transfer. These binaphthyl-based Pt(Ⅱ)complexes bearing coordinated atoms far away from chiral axis exhibit no Pt-Pt interactions but colorful concentrationdependent phosphorescence with quantum yield up to 86.4% and could be applied as emitters in highly efficient solutionprocessed organic light-emitting diodes to achieve luminance, luminance efficiency, power efficiency, external quantum efficiency, and asymmetry factor up to 8.94 × 10^(3)cd m^(-2), 41.9 cd A-1, 18.8 lm W^(-1), 12.6% and 2.98 × 10^(-3), respectively. Therefore,the present work affords a new and simple way to utilize the inherently asymmetric advantage of chirality for the design of D-Abased organic dyes.展开更多
The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugate...The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugated system, they can go through multiple intramolecular and intermolecular hydrogen bonds promoted excited-state intramolecular proton-transfer （ESIPT） to display strong blue, green, yellow, and orange aggregation-induced emission （ALE） with large Stokes shifts （up to 184 nm） and high fluorescence quantum yields （φ up to 0.20）. Unusual mechanochromic fluorescence en- hancements are also found in some solid samples. Through coordination, hydrogen and halogen bonds, these flexible molecules can be used as Mg2＋ （φ up to 0.46） probes, universal anion （φ up to 0.14） and unprotected amino acids （φ up to 0.16） probes, and chiral diamine （enantiomeric selectivity and φ up to 0.36 and 0.062, respectively） receptors. Combining their advantages of AlE and biocompatibility, these low cytotoxic dyes have potential application in living cell imaging. Furthermore, the effects of different functional groups on the molecule arrangement, ESIPT, AlE, probe, and chiral recognition properties are also examined, which provide a simple and bright paradigm for the design of multiple-stimuli-responsive smart materials.展开更多
基金supported by the National Natural Science Foundation of China (21871192)the Major Program of Guangdong Basic and Applied Research (2019B030302009)。
文摘D-A charge transfer, including through-bond charge transfer and through-space charge transfer between two different electron donors(D) and electron acceptors(A), is a fundamental and powerful tool to tune the optical properties of organic dyes. Herein,we demonstrate a unique strategy to tune phosphorescence and circularly polarized luminescence properties of axially chiral binuclear Pt(Ⅱ) complexes through long-range charge transfer, even though these molecules have two totally identical segments on either side of the chiral core. The presence of axial chirality would break not only the symmetry of molecular structure and π-conjugation system but also the symmetry of charge distribution for long-range charge transfer. These binaphthyl-based Pt(Ⅱ)complexes bearing coordinated atoms far away from chiral axis exhibit no Pt-Pt interactions but colorful concentrationdependent phosphorescence with quantum yield up to 86.4% and could be applied as emitters in highly efficient solutionprocessed organic light-emitting diodes to achieve luminance, luminance efficiency, power efficiency, external quantum efficiency, and asymmetry factor up to 8.94 × 10^(3)cd m^(-2), 41.9 cd A-1, 18.8 lm W^(-1), 12.6% and 2.98 × 10^(-3), respectively. Therefore,the present work affords a new and simple way to utilize the inherently asymmetric advantage of chirality for the design of D-Abased organic dyes.
基金This work was supported by the National Natural Science Foundation of China （No. 21372169） and Sichuan Provincial Foundation （2008SG0021）. We acknowledge the comprehensive training platform of the specialized laboratory of the College of Chemistry, Sichuan University, for material analysis. We acknowledge the comprehensive training platform of the specialized laboratory of the College of Chemistry, Sichuan University, for material analysis. We would like to thank the Analytical ＆ Testing Center of Sichuan University for CCD X-ray single crystal diffractometer work and circular dichroism CD spectrometer work. We are grateful to Daibing Luo and Yani Xie for help with the single crystal and circular dichroism measurements.
文摘The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugated system, they can go through multiple intramolecular and intermolecular hydrogen bonds promoted excited-state intramolecular proton-transfer （ESIPT） to display strong blue, green, yellow, and orange aggregation-induced emission （ALE） with large Stokes shifts （up to 184 nm） and high fluorescence quantum yields （φ up to 0.20）. Unusual mechanochromic fluorescence en- hancements are also found in some solid samples. Through coordination, hydrogen and halogen bonds, these flexible molecules can be used as Mg2＋ （φ up to 0.46） probes, universal anion （φ up to 0.14） and unprotected amino acids （φ up to 0.16） probes, and chiral diamine （enantiomeric selectivity and φ up to 0.36 and 0.062, respectively） receptors. Combining their advantages of AlE and biocompatibility, these low cytotoxic dyes have potential application in living cell imaging. Furthermore, the effects of different functional groups on the molecule arrangement, ESIPT, AlE, probe, and chiral recognition properties are also examined, which provide a simple and bright paradigm for the design of multiple-stimuli-responsive smart materials.
