CRYSTENGCOMM
·
2024
·
IF 2.6
Wenxiu Yao,Pengfei Wu,Yidan Xie,Xinyu Shen,Shuwei Xia,Liangmin Yu
A series of charge transfer cocrystals with fluorescent properties involving 1,2,4,5-tetracyanobenzene (TCNB, C10H2N4) as the acceptor, fluorene (FR, C13H10) and its bromide 2-bromofluorene (2-BrFR, C13H9Br), carbazole (CZ, C12H9N) and its bromide 2-bromocarbazole (2-BrCZ, C12H8BrN) as donors were synthesized via cocrystal design strategies. The formation mechanism of the crystal structure was explored by density functional theory at molecular level. The stacking structure of the cocrystal was formed by the combined interaction of charge transfer interactions, π-π interactions and hydrogen bonding. N atom of donors in TCNB-CZ and TCNB-2-BrCZ could enhance the charge transfer, appear as a red shift of the fluorescence emission wavelength. Conversely, Br atom in TCNB-2-BrFR and TCNB-2-BrCZ weaken the charge transfer, giving a blue shift in fluorescence emission spectrum. The four new cocrystals exhibit tunable luminescence from green (529 nm) to yellow (552 nm) and to red (604 nm and 614 nm). It was found that the introduction of N and Br atoms in the assembly units can not only regulate the luminescence range of the cocrystals, but also adjust the luminescence efficiency, which provides a strategy for the development of promising organic luminescent materials.
研究领域:
材料科学
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有机化学
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光化学
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晶体工程
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2018
·Vol. 9
·期 17
·2295-2301
·
IF 4.927
Yin Zhao,Hailing Chen,Lu Yin,Xiaoxiao Cheng,Wei Zhang,Xiulin Zhu
In this contribution, we report the first odd–even and side chain length dependence on the chiral induction of achiral polydialkylfluorenes (PFs) by chiral solvation. Firstly, a series of PFs, substituted at the C9-position by linear alkyl chains of different lengths and branched side chains (PF5, PF6, PF7, PF8, PF9, PF10 and PF2/6), were designed and synthesized by the Kumada catalyst transfer polycondensation (KCTP) or typical Yamamoto-type coupling reaction. PFs with linear alkyl chains of different lengths (PF5, PF6, PF7, PF8, PF9 and PF10) are all good achiral candidates to form chiral supramolecular assemblies in neat limonene. UV-visible absorbance spectra validated the production of chiral β-phase conformers in PF5, PF7, PF8, PF9 and PF10/limonene aggregates, and another chiral conformer in PF6/limonene aggregates. Interestingly, an “odd–even” effect in circular dichroism (CD) signs for the chiral β-phase of PF/limonene aggregates was firstly observed, depending on whether the alkyl side chain was of odd or even length. Moreover, the disassembling temperature for optically active PF gels or aggregates also depends on both the length and odd–even number of side chains. Our results indicate that there is a complex interplay between the transfer of solvent chirality into supramolecular helicity and the length of the alkyl side chain. These results are critical for building optically active π-conjugated polymers from achiral ones, since subtle modifications in the length of the side alkyl chain can strongly influence the chirality sign.
研究领域:
聚合物化学
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超分子化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 35
·24181-24190
·
IF 3.9
Liandong Ye,Min Liu,Xiao Wang,Zhihong Yu,Zhihao Huang,Nianchen Zhou,Zhengbiao Zhang,Xiulin Zhu
Sequences can have a dramatic impact on the unique properties and self-assembly in natural macromolecules, which has received increasing interest. Herein, we report a series of discrete amphiphilic co-oligomers with the same composition but different building blocks in a semirigid backbone. These sequence-defined oligomers possess two primary amine groups on the side chain of the azobenzene building block, and hence, they become amphipathic due to quaternization of the amine groups when protonated in acidic aqueous solution. These oligomer isomers assembled into different nanoparticles, including nanofibers, hollow vesicles and spherical micellar complexes, in a THF/water/HCl mixture under the same conditions. UV-vis absorption spectra, differential scanning calorimetry (DSC) and X-ray scattering (XRD) experiments combined with theoretical calculations reveal that the sequence-controlled co-oligomers induce different molecular packing conformations and arrangement modes of building blocks in self-assembly. Furthermore, these self-assembled nanoparticles demonstrate photoresponsive morphological transformation and fluorescence emission under UV light irradiation due to trans-to-cis photoisomerization of azobenzene. This work demonstrates that customizing functional nanoparticles can be achieved by controlling the sequence structure in synthetic co-oligomers.
研究领域:
材料科学
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纳米技术
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高分子化学
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物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）