CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Pengpeng Li,Huaizhi Gao,Biao Zhao,Jianping Deng
As one of the most challenging scientific issues in the world, the origin of natural homochirality has attracted intense attention and has been widely studied. Herein, a unique, simple, and scalable approach to achieve the birth of helical chirality is presented. In the absence of any additional physical or chemical chiral source, optical activity has been acquired in the absolutely achiral polymer casting systems. Specifically, optically active and recyclable composite films are fabricated from casting racemic helical substituted polyacetylenes and achiral polar polymeric matrices. The induced dissymmetry intensity can be flexibly adjusted by controlling the temperature for fabricating the films and/or the recycling casting times. This study reveals that weak intermolecular interactions can enantioselectively drive racemic helices to be far from the original equilibrium state, thereby resulting in the generation of helical chirality that can be further amplified and maintained in solid films. To demonstrate the utility of the as-obtained chiroptical films, circularly polarized luminescence (CPL) has been achieved by judiciously combining an achiral fluorescent source with the casting films. The finding of symmetry breaking at the macromolecular level can provide useful insights into the understanding of natural homochirality and the design of chiral functional materials.
研究领域:
化学
·
材料科学
·
生物学
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2015
·
IF 5.8
Jia-Li Chen,Li Yang,Qian Wang,Zhi-Qiang Jiang,Na Liu,Jun Yin,Yunsheng Ding,Zong-Quan Wu
Polymerization of phenyl isocyanide using achiral Pd(II) initiator with the presence of chiral l- or d-lactide (l-LA or d-LA) as additive was found to proceed in helix-sense-selective manner. The polymerization of achiral phenyl isocyanide, 4-isocyanobenzoyl-2-aminoisobutyric acid decyl ester (1) by this method produced optically active helical poly-1m(L), whose chirality was solely come from the helical conformation without containing of any other chiral atoms. The added chiral LA can be facilely recovered and reused in the helix-sense-selective polymerizations without significantly loss of its chiral induction, and the chiral economy of the polymerization is high. When enantiomerically pure phenyl isocyanide bearing an R- or S-alanine pendent with a long n-decyl chain (1r or 1s) were polymerized by this method, the polymerization was found to proceed in a highly enantiomer-selective manner with one of the enantiomers preferentially polymerized over the antipode by a factor of 3.6. Single-handed helical polyisocyanides can be achieved when the chirality of the monomer was appropriately matched with the added LA.
研究领域:
高分子化学
·
有机化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Huilin He,Mengjia Cen,Jiawei Wang,Yiwei Xu,Jianxun Liu,Wenfeng Cai,Delai Kong,Ke Li,Dan Luo,Tun Cao,Yan Jun Liu
Chirality induction, transfer, and manipulation have aroused great interest in achiral nanomaterials. Here, we demonstrate strong upconverted circularly polarized luminescence from achiral core–shell upconversion nanoparticles (UCNPs) via a plasmonic chiral metasurface-induced optical chirality transfer. The Yb3+-sensitized core–shell UCNPs with good dispersity exhibit intense upconversion luminescence of Tm3+ and Nd3+ through the energy transfer process. By spin-coating the core–shell UCNPs on this chiral metasurface, strong enhancement and circular polarization modulation of upconversion luminescence can be achieved due to resonant coupling between surface plasmons and upconversion nanoparticles. In the UCNPs-on-metasurface composite, a significant upconversion luminescence enhancement can be achieved with a maximum enhancement factor of 32.63 at 878 nm and an overall enhancement factor of 11.61. The luminescence dissymmetry factor of the induced upconverted circularly polarized luminescence can reach 0.95 at the emission wavelength of 895 nm. The UCNPs-on-metasurface composite yields efficient modulation for the emission intensity and polarization of UCNPs, paving new pathways to many potential applications in imaging, sensing, and anticounterfeiting fields.
研究领域:
光学
·
纳米科技
·
材料科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Zhen-Yu Chen,Qin-Long Hong,Hai-Xia Zhang,Jian Zhang
By enhancing steric hindrance of substituents on the imidazole ring, the fan-shaped molecule of a tridentate boron imidazolate ligand (KBH(2-ipim)3, 2-ipim = 2-isopropylimidazolate) with racemic chirality was obtained. Then, seven novel boron imidazolate frameworks (BIFs) were prepared by mixing KBH(2-ipim)3 ligands with various derivatives of benzene carboxylic acid under solvothermal conditions. All of these seven materials contain a ladder-like zinc-boron-imidazolate chain as a basic building block, and the ligand BH(2-ipim)3– exists in the same handedness in one chain. The structural variations are associated with the position of substituents of the auxiliary ligand. Of particular interest is the spontaneous resolution of BH(2-ipim)3– ligands into two independent enantiomorphous homochiral structures, BIF-131-S and BIF-131-R, which contain both a chiral chain and an absolute helix embedded in the nets.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2020
·Vol. 11
·期 12
·2089-2097
·
IF 5.342
Xiaoxiao Cheng,Tengfei Miao,Haotian Ma,Lu Yin,Wei Zhang,Zhengbiao Zhang,Xiulin Zhu
The induction of supramolecular chirality from achiral azobenzene-containing polymers has been widely investigated in solution and in the film state. However, the construction of micron-sized optically active azobenzene-containing polymer particles (Azo-OAPPs) with supramolecular chirality in heterogeneous systems has not yet been demonstrated. Here, Azo-OAPPs were successfully prepared from achiral Azo-containing monomers for the first time by helix-sense-selective dispersion polymerization (HSSDP), also known as asymmetric helix-chirogenic polymerization. The trans-Azo units in the polymer side chains constituting the OAPPs adopt supramolecular helical structures with preferential screw sense, and thus the OAPPs have remarkable chiral properties. The Azo-OAPPs in an ethanol dispersion were characterized by CD and UV-vis spectroscopy, and this demonstrated the successful transfer of chirality from the chiral octanol molecules to the polymer particles during HSSDP. In addition, the supramolecular chirality of the Azo-OAPPs could be easily controlled by adjusting the volume of chiral solvent, polymerization time and UV light irradiation time. The morphologies and sizes of the Azo-OAPPs were investigated by TEM and DLS studies. Moreover, a supramolecular helical system in which covalent bonds were introduced into the Azo-OAPPs using a divinylbenzene (DVB) crosslinker was also investigated. Interestingly, the chirality of the crosslinked Azo-OAPPs demonstrated improved UV-resistance compared with the non-crosslinked counterparts. The present study develops a novel strategy for preparing Azo-OAPPs with supramolecular chirality from an achiral source, which is expected to find potential applications in chiroptical materials.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）