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
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Xicun Zhang,Wei Shi,Xin Chen,Zhengfeng Xie
A type of isocyano-functionalized, 1,8-naphthalimide-based chromophore ( M2 ) was successfully synthesized from its primary amine-derivatived precursor ( M1 ) compound. The chemical structure of M2 was verified by FT-IR, NMR and HRMS analyses. The presence of electron-withdrawing isocyano group brought significant influence to the optical properties of M2 . Distinct from the yellowish green emission of its precursor ( M1 ), M2 emitted ultraviolet light (with the emission peak at ∼389 nm, excited by 352 nm) in THF-water [V THF /V water = 3/7, buffered with 5 mM sodium dihydrogen phosphate-disodium hydrogen phosphate (PB), pH = 7.4] co-solvent system. Interestingly, M2 exhibited distinctive and selective optical response (with significant enhancement of emission at ∼560 nm) toward Hg 2+ . In Hg 2+ titration process, PL spectra of M2 displayed contiguous ratiometric alteration (simultaneous decreasing at 389 nm and increasing at 560 nm). Hg 2+ -assisted hydration of isocyano group to amino group on M2 was proposed as the plausible probing mechanism in this current case.
研究领域:
分析化学
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环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 6
·2567-2576
·
IF 4.569
Aijia Gao,Fangfang Li,Zhi Xu,Changchun Ji,Jing Gu,Ying-Hua Zhou
The development of heterogeneous catalysts for promoting epoxide cycloaddition with carbon dioxide is highly desirable for recycling CO2 and achieving the goal of carbon neutrality. Herein, we designed and synthesized Zr-based metal organic frameworks (MOFs) by implanting functional guanidyl into the framework via mixing different molar ratios of 4-guanidinobenzoic acid (Gua) with 1,4-benzenedicarboxylic acid (BDC). Consequently, a small sized Zr-MOF (∼350 nm) can be prepared by implanting Gua with 20% molar ligands, denoted as UiO-66-Gua0.2(s). Compared to large sized and different guanidyl Zr-MOFs, UiO-66-Gua0.2(s) exhibited an optimal activity on catalyzing epoxide cycloaddition with CO2 in the presence of the Bu4NBr cocatalyst. A yield of 97% for the product of chloropropene carbonate was achieved at 90 °C under 1 atm CO2. The great performance of UiO-66-Gua0.2(s) might be attributed to the synergistic effect of guanidyl groups as hydrogen-bond donors and Zr centers acting as Lewis-acidic sites. In addition, the heterogeneous catalyst of UiO-66-Gua0.2(s) exhibited a great versatility towards converting other epoxides and a satisfactory recyclability for five consecutive runs. Moreover, a plausible reaction mechanism has been proposed for UiO-66-Gua0.2(s) in promoting CO2 epoxide cycloaddition reactions.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemElectroChem
·
2021
·Vol. 8
·期 19
·3716-3725
·
IF 4.59
Jing Lu,Shuai Li,Liqin Jiang,Tianxiang Yang,Weizhen Fan,Wenlian Wang,Xiaoyang Zhao,Xiaoxi Zuo,Junmin Nan
Graphical Isocyanoethyl methacrylate (IMA) containing −N=C=O group is developed as a bifunctional electrolyte additive through the film-forming, H 2 O removal, and HF reduction to modify the electrode-electrolyte interfaces and improve the performance of high-nickel LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811)/graphite lithium-ion battery. After 450 cycles under the normal voltage range of 2.75 to 4.20 V, the capacity retention of the battery with 0.5 wt.% IMA additive increases from 50.7 % to 78.0 % compared to the battery without the additive. Under the high voltage range of 2.75 to 4.40 V, the capacity retention of the battery with IMA increases from 62.8 % to 81.9 % after 150 cycles. By now, as the promising high-energy cathode materials of lithium-ion batteries (LIBs), the high-nickel LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) still have technical problems such as poor electrode-electrolyte interface stability and sensitivity to H 2 O and HF in the electrolyte to be solved. In this work, isocyanoethyl methacrylate (IMA) containing −N=C=O group is developed as a bifunctional electrolyte additive through the film-forming, H 2 O removal, and HF reduction to modify the electrode-electrolyte interfaces and improve the performance of NCM811/graphite LIBs. After 450 cycles under the normal voltage range of 2.75 to 4.20 V, the capacity retention of the battery with 0.5 wt.% IMA additive increases from 50.7 % to 78.0 % compared to the battery without the additive. And under the high voltage range of 2.75 to 4.40 V, the capacity retention of the battery with IMA increases from 62.8 % to 81.9 % after 150 cycles. It is demonstrated that the IMA additive as the H 2 O and HF scavenger of electrolyte also facilitate the electrochemical oxidation-reduction reactions on two electrodes to form high-quality interfacial films, which stabilizes the anode and cathode interfaces and subsequently improves the cycling performance of the batteries. These results show that the electrolyte with IMA additive has promising prospects in the application of high-nickel NCM-based LIBs and provide the idea to evaluate the organic molecules containing −N=C=O group as the functional electrolyte additives as well.
研究领域:
材料科学
·
电化学
·
电池技术
✓ 已验证
产品关联
DOI
高影响因子
TETRAHEDRON-ASYMMETRY
·
2010
·
IF 2.625
Zhen-Wei Zhang,Gui Lu,Miao-Miao Chen,Ning Lin,Yong-Bo Li,Tamio Hayashi,Albert S.C. Chan
The first asymmetric Mannich-type reaction of methyl isocyanoacetate with N -sulfonylimines catalyzed by cinchona alkaloid derivatives yielded 2-imidazolines with high diastereoselectivities and good enantioselectivities (up to >99:1 dr and 70% ee). This reaction provided a convenient route to access various substituted 2-imidazoline-4-carboxylates and related α,β-diamino acids in high enantiomeric purities.
研究领域:
有机化学
·
药物化学
·
不对称合成
·
催化化学
·
生物有机化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）