A facile,rapid and efficient method for the synthesis of molecular tweezers containing chiral unsymmetrical urea unit in solvent- free conditions using microwave was reported.
An efficient and simple method for the synthesis of new chiral aromatic amide molecular tweezers by irradiation with microwave under solvent-free conditions has been developed. Its main advantages are short reaction t...An efficient and simple method for the synthesis of new chiral aromatic amide molecular tweezers by irradiation with microwave under solvent-free conditions has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process.展开更多
A novel type of molecular tweezers with different chiral center and cleft has been designed and prepared by using α- hyodeoxycholic acid as spacer and D/L-amino acid methyl ester as chiral arm attached at 3-position....A novel type of molecular tweezers with different chiral center and cleft has been designed and prepared by using α- hyodeoxycholic acid as spacer and D/L-amino acid methyl ester as chiral arm attached at 3-position. Their structures were elucidated by ^1H NMR, FTIR and elemental analysis. Their recognition properties for various D/L-amino acid methyl esters were also investigated. The preliminary results indicated that these chiral single-armed molecular tweezers exhibited good recognition ability for D/L-amino acid methyl esters with high association constant （up to 5.24 × 10^3 L mol^-1）.展开更多
A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H ...A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H NMR, IR, MS spectra and elemental analysis. These molecular tweezers showed good binding ability for neutral molecules and chiral molecules.展开更多
A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms. Instead of using toxic phosgene, the triphosgene was employed in synthesis ...A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms. Instead of using toxic phosgene, the triphosgene was employed in synthesis of the molecular tweezers receptors. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.展开更多
A novel type of chiral molecular tweezers has been designed and synthesized by using chenodeoxy cholic acid as spacer and the aromatic compounds as arm. Their structures were characterized by 1HNMR, IR, MS spectra an...A novel type of chiral molecular tweezers has been designed and synthesized by using chenodeoxy cholic acid as spacer and the aromatic compounds as arm. Their structures were characterized by 1HNMR, IR, MS spectra and elemental analysis. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.展开更多
Herein,a novel molecular tweezer based on 2,2'-bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes recognition.The syn conformation of the molecule,which was obtained by Zn(Ⅱ)coordinati...Herein,a novel molecular tweezer based on 2,2'-bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes recognition.The syn conformation of the molecule,which was obtained by Zn(Ⅱ)coordination,gives rise to a proper cavity to interact with fullerene guests to form a stable 1:1 complex in toluene solution.It exhibits distinct binding selectivity towards C_(60)over C_(70).Moreover,the fullerene recognition capacity can be adequately suppressed by importing H_(2)PO_(4)^(-)to competitively capture Zn(Ⅱ)along with syn-anti conformational conversion.Subsequently,the molecular tweezer regenerated to bind the fullerene by introducing the Ca^(2+)into the system.Significantly,the association-disassociation process can be switched reversibly and repeatedly.展开更多
A novel type of host-guest recognition systems have been developed on the basis of a Au(Ⅲ) molecular tweezer receptor and chiral Pt(Ⅱ) guests. The complementary host-guest motifs display high non-covalent binding af...A novel type of host-guest recognition systems have been developed on the basis of a Au(Ⅲ) molecular tweezer receptor and chiral Pt(Ⅱ) guests. The complementary host-guest motifs display high non-covalent binding affinity (Ka: ∼10^(4) L/mol) due to the participation of two-fold intermolecular π-π stacking interactions. Both phosphorescence and chirality signals of the Pt(Ⅱ) guests strengthen in the resulting host-guest complexes, because of the cooperative rigidifying and shielding effects rendered by the tweezer receptor. Their intensities can be reversibly switched toward pH changes, by taking advantage of the electronic repulsion effect between the protonated form of tweezer receptor and the positive-charged guests in acidic environments. Overall, the current study demonstrates the feasibility to enhance and modulate phosphorescence and chirality signals simultaneously via molecular tweezer-based host-guest recognition.展开更多
Coordination-driven self-assembly strategy has demonstrated the efficiency and versatility to construct well-ordered supramolecular coordination complexes （SCCs） such as discrete metallacycles and metallacages. In r...Coordination-driven self-assembly strategy has demonstrated the efficiency and versatility to construct well-ordered supramolecular coordination complexes （SCCs） such as discrete metallacycles and metallacages. In recent years, it has aroused tremendous interest to build more complexed self-assembled structures via the implementation of additional non-covalent recognition motifs on the SCCs platform. In this work, we have successfully attained this objective, with the elaborate manipulation of non-interfering pyridine-Pt2＋ and molecular tweezer/guest complexation in a hierarchical self-assembly manner. The resulting SCCs-based linear supramolecular polymers exhibit intriguing NIR-emissive behaviors, primarily attributed to the presence of intermolecular Pt（II）-Pt（II） metal-metal interactions in the non-covalent tweezering structure. Hence, supramolecular engineering of multiple non-covalent interactions offers a feasible avenue toward functional materials with tailored properties.展开更多
A novel type of molecular tweezer receptors based on deoxycholic acid has been designed and synthesized and their binding properties were examined by UV-vis spectral titration. These molecular tweezers showed a high s...A novel type of molecular tweezer receptors based on deoxycholic acid has been designed and synthesized and their binding properties were examined by UV-vis spectral titration. These molecular tweezers showed a high selectivity toward F^- over Cl^-, Br^-, I^-, AcO^-, H2PO4^-.展开更多
文摘A facile,rapid and efficient method for the synthesis of molecular tweezers containing chiral unsymmetrical urea unit in solvent- free conditions using microwave was reported.
基金supported by the Doctors Innovation Foundation of Southwest University for Nationalities(No.08NBS002).
文摘An efficient and simple method for the synthesis of new chiral aromatic amide molecular tweezers by irradiation with microwave under solvent-free conditions has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process.
基金support from National Natural Science Foundation of China(No.20272038).
文摘A novel type of molecular tweezers with different chiral center and cleft has been designed and prepared by using α- hyodeoxycholic acid as spacer and D/L-amino acid methyl ester as chiral arm attached at 3-position. Their structures were elucidated by ^1H NMR, FTIR and elemental analysis. Their recognition properties for various D/L-amino acid methyl esters were also investigated. The preliminary results indicated that these chiral single-armed molecular tweezers exhibited good recognition ability for D/L-amino acid methyl esters with high association constant （up to 5.24 × 10^3 L mol^-1）.
文摘A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H NMR, IR, MS spectra and elemental analysis. These molecular tweezers showed good binding ability for neutral molecules and chiral molecules.
基金We are very grateful to the National Natural Science Foundation of China(project:No.29772024)for the financial support.
文摘A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms. Instead of using toxic phosgene, the triphosgene was employed in synthesis of the molecular tweezers receptors. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.
文摘A novel type of chiral molecular tweezers has been designed and synthesized by using chenodeoxy cholic acid as spacer and the aromatic compounds as arm. Their structures were characterized by 1HNMR, IR, MS spectra and elemental analysis. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.
基金the financial support of the National Natural Science Foundation of China(No.21801060)Natural Science Foundation of Hebei Province(Nos.B2019205172,226Z1501G)+1 种基金China Postdoctoral Science Foundation(No.2020TQ0087)the support from the National Demonstration Center for Experimental Chemistry Education of Hebei Normal University。
文摘Herein,a novel molecular tweezer based on 2,2'-bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes recognition.The syn conformation of the molecule,which was obtained by Zn(Ⅱ)coordination,gives rise to a proper cavity to interact with fullerene guests to form a stable 1:1 complex in toluene solution.It exhibits distinct binding selectivity towards C_(60)over C_(70).Moreover,the fullerene recognition capacity can be adequately suppressed by importing H_(2)PO_(4)^(-)to competitively capture Zn(Ⅱ)along with syn-anti conformational conversion.Subsequently,the molecular tweezer regenerated to bind the fullerene by introducing the Ca^(2+)into the system.Significantly,the association-disassociation process can be switched reversibly and repeatedly.
基金financially supported by the National Natural Science Foundation of China(Nos.21922110 and 21871245)the Fundamental Research Funds for the Central Universities(No.WK3450000005)the Starry Night Science Fund at Shanghai Institute for Advanced Study,Zhejiang University(No.SNZJU-SIAS-006)。
文摘A novel type of host-guest recognition systems have been developed on the basis of a Au(Ⅲ) molecular tweezer receptor and chiral Pt(Ⅱ) guests. The complementary host-guest motifs display high non-covalent binding affinity (Ka: ∼10^(4) L/mol) due to the participation of two-fold intermolecular π-π stacking interactions. Both phosphorescence and chirality signals of the Pt(Ⅱ) guests strengthen in the resulting host-guest complexes, because of the cooperative rigidifying and shielding effects rendered by the tweezer receptor. Their intensities can be reversibly switched toward pH changes, by taking advantage of the electronic repulsion effect between the protonated form of tweezer receptor and the positive-charged guests in acidic environments. Overall, the current study demonstrates the feasibility to enhance and modulate phosphorescence and chirality signals simultaneously via molecular tweezer-based host-guest recognition.
基金financially supported by the National Natural Science Foundation of China(No.21674106)the Fundamental Research Funds for the Central Universities(No.WK3450000001)CAS Youth Innovation Promotion Association(No.2015365)
文摘Coordination-driven self-assembly strategy has demonstrated the efficiency and versatility to construct well-ordered supramolecular coordination complexes （SCCs） such as discrete metallacycles and metallacages. In recent years, it has aroused tremendous interest to build more complexed self-assembled structures via the implementation of additional non-covalent recognition motifs on the SCCs platform. In this work, we have successfully attained this objective, with the elaborate manipulation of non-interfering pyridine-Pt2＋ and molecular tweezer/guest complexation in a hierarchical self-assembly manner. The resulting SCCs-based linear supramolecular polymers exhibit intriguing NIR-emissive behaviors, primarily attributed to the presence of intermolecular Pt（II）-Pt（II） metal-metal interactions in the non-covalent tweezering structure. Hence, supramolecular engineering of multiple non-covalent interactions offers a feasible avenue toward functional materials with tailored properties.
基金We are very grateful to the National Natural Science Foundation of China(No.20272038)for the financial support.
文摘A novel type of molecular tweezer receptors based on deoxycholic acid has been designed and synthesized and their binding properties were examined by UV-vis spectral titration. These molecular tweezers showed a high selectivity toward F^- over Cl^-, Br^-, I^-, AcO^-, H2PO4^-.
