A series of isostructural d/f molecular compounds Zn（H2L）Ln（NO3）3·CH3OH（Ln = Dy（1）, Tb（2） and Sm（3）） were synthesized by the introduction of a designed multifunctional ligand N,N？,N？？,N？？？-tetra...A series of isostructural d/f molecular compounds Zn（H2L）Ln（NO3）3·CH3OH（Ln = Dy（1）, Tb（2） and Sm（3）） were synthesized by the introduction of a designed multifunctional ligand N,N？,N？？,N？？？-tetra（2-hydroxy-3-methoxy-5-methylbenzyl）-1,4,7,10-tetraazacyclododecan（H4L = C（44）H（60）N4O8）. In the isostructural molecules, each crystallographically independent Zn2＋ and Ln3＋ centers are connected by two phenolic oxygen atoms. For the six-coordinate Zn-（2＋） ion, the coordination geometry can be viewed as a regular bicapped square pyramid. While for the ten-coordinate Ln-（3＋） ion, if each O,O？-chelated nitrate ligand is seen as a single coordination site, the coordination geometry can be viewed as a distorted pentagonal bipyramid. The fluorescent spectra show that compounds 2 and 3 exhibited characteristic sharp emissions of Tb-（3＋） and Sm-（3＋）, respectively, while compound 1 was found to be a single-component white-light-emitting complex in the solid state. Thermal stabilities of the three compounds were investigated by using thermal gravimetric analysis. In addition, the thermal decomposition of compound 1 was confirmed by temperature-dependent powder X-ray diffraction technique.展开更多
A new complex has been synthesized with o-methylbenzoyl-benzoic acid（HL） and 1,10-phenanthroline（phen） in the mixture of water and ethanol. It crystallizes in monoclinic, space group C2/c with a = 13.6328（18）, b...A new complex has been synthesized with o-methylbenzoyl-benzoic acid（HL） and 1,10-phenanthroline（phen） in the mixture of water and ethanol. It crystallizes in monoclinic, space group C2/c with a = 13.6328（18）, b = 17.7876（18）, c = 19.998（2）, β = 104.720（4）o, C54H48N4O11Zn, Mr = 994.33, V = 4690.2（9）3, Dc = 1.408 g/cm3, Z = 4, F（000） = 2072, μ（MoKα） = 0.59 mm-1, R = 0.0736 and wR = 0.2029. The crystal structure shows that the zinc ions are coordinated with two oxygen atoms from two HL molecules and four nitrogen atoms from two phen molecules, forming distorted octahedral coordination geometry. The fluorescent and thermal stability properties of the complex are studied. The result shows that it has one fluorescent emission band at around 412 nm. In addition, the complex is stable under 210 ℃.展开更多
The ligand of N-（2-hydroxybenzylideneamino）-1,8-naphthalimide （HL） and its metal complexes of CuL2 （1） and CoL2 （2） have been synthesized. Elemental analysis, IR and X-ray single-crystal diffraction characteri...The ligand of N-（2-hydroxybenzylideneamino）-1,8-naphthalimide （HL） and its metal complexes of CuL2 （1） and CoL2 （2） have been synthesized. Elemental analysis, IR and X-ray single-crystal diffraction characterizations for 1 and 2 have been carried out. In the complexes of 1 and 2, the central metallic ions of Cu^2＋ and Co^2＋ coordinate with two deprotonated ligands of L-, respectively and adopt distorted square planar geometries. The thermal analysis result shows that the two complexes undergo two similar decomposition processes because of their similar geometric configurations. For the two complexes, fluorescence spectra measurements indicate that complex CoL2 emits stronger blue fluorescence than HL and the complex CuL2 does not emit fluorescence at all.展开更多
The thermal stability of triple helical structure plays a critical role in collagen biosynthesis,function and degradation.CD technique was utilized to characterize the thermal stability of synthetic collagen mimic pep...The thermal stability of triple helical structure plays a critical role in collagen biosynthesis,function and degradation.CD technique was utilized to characterize the thermal stability of synthetic collagen mimic peptides.Fluorescence spectroscopy is widely used with easy access all around the world because of its inexpensive instrumentation,low operation cost,easy operation,and high sensitivity.Here we have developed an alternative fluorescence method to detect the thermal stability of collagen mimic peptides.We have demonstrated that fluorescence spectroscopy could measure the thermal stability of collagen mimic peptides with low concentrations under different circumstances.This highly sensitive fluorescence self-quenching assay will greatly expedite the studies of sequence-dependent properties of collagen mimic peptides,and it has great potential in the application of determining the thermal stability of triple helix systems such as collagens,collectins,adiponectin,macrophage scavenger and C1q.展开更多
Nanocrystals(NCs)of cesium lead halide perovskites are optically unstable,which prevents their use in optical sensors.The combination of perovskite NCs and metal single atoms(SAs)may be a good solution to this issue.U...Nanocrystals(NCs)of cesium lead halide perovskites are optically unstable,which prevents their use in optical sensors.The combination of perovskite NCs and metal single atoms(SAs)may be a good solution to this issue.Unfortunately,depositing metal SAs on perovskite NCs remains a challenge due to relative weak metal-halide bonds.Herein,we present that,via a photo assisted method using cesium lead halide perovskite NCs as host material to anchor Y single atoms,we successfully synthesize Y SA anchored CsPbBr_(3)NCs(Y-SA/CsPbBr_(3)NCs)with outstanding fluorescence stability through the formation of two Y-O bonds and two Y-Br bonds.In comparison to bare CsPbBr_(3)NCs,Y-SA/CsPbBr_(3)NCs possess more stable optical characteristics.The as-synthesized Y-SA/CsPbBr_(3)NCs can be employed as a colorimetric platform to perform rapid CH_(3)I sensing.Detection limit of 0.044 ppm is exhibited in this approach with excellent anti-interference performance.The YSA/CsPbBr_(3)NCs-based system has been applied to the detection of CH_(3)I in sweet potato samples with satisfying results.展开更多
基金supported by the Natural Science Foundation of China(No.21171165,21201165 and 91122015)
文摘A series of isostructural d/f molecular compounds Zn（H2L）Ln（NO3）3·CH3OH（Ln = Dy（1）, Tb（2） and Sm（3）） were synthesized by the introduction of a designed multifunctional ligand N,N？,N？？,N？？？-tetra（2-hydroxy-3-methoxy-5-methylbenzyl）-1,4,7,10-tetraazacyclododecan（H4L = C（44）H（60）N4O8）. In the isostructural molecules, each crystallographically independent Zn2＋ and Ln3＋ centers are connected by two phenolic oxygen atoms. For the six-coordinate Zn-（2＋） ion, the coordination geometry can be viewed as a regular bicapped square pyramid. While for the ten-coordinate Ln-（3＋） ion, if each O,O？-chelated nitrate ligand is seen as a single coordination site, the coordination geometry can be viewed as a distorted pentagonal bipyramid. The fluorescent spectra show that compounds 2 and 3 exhibited characteristic sharp emissions of Tb-（3＋） and Sm-（3＋）, respectively, while compound 1 was found to be a single-component white-light-emitting complex in the solid state. Thermal stabilities of the three compounds were investigated by using thermal gravimetric analysis. In addition, the thermal decomposition of compound 1 was confirmed by temperature-dependent powder X-ray diffraction technique.
基金Supported by the Natural Science Foundation of Hunan Province(No.11JJ9006)Key Project of Science and Technology Plan of Hunan Province(2012FJ2002)the Construct Program of the Key Discipline in Hunan Province
文摘A new complex has been synthesized with o-methylbenzoyl-benzoic acid（HL） and 1,10-phenanthroline（phen） in the mixture of water and ethanol. It crystallizes in monoclinic, space group C2/c with a = 13.6328（18）, b = 17.7876（18）, c = 19.998（2）, β = 104.720（4）o, C54H48N4O11Zn, Mr = 994.33, V = 4690.2（9）3, Dc = 1.408 g/cm3, Z = 4, F（000） = 2072, μ（MoKα） = 0.59 mm-1, R = 0.0736 and wR = 0.2029. The crystal structure shows that the zinc ions are coordinated with two oxygen atoms from two HL molecules and four nitrogen atoms from two phen molecules, forming distorted octahedral coordination geometry. The fluorescent and thermal stability properties of the complex are studied. The result shows that it has one fluorescent emission band at around 412 nm. In addition, the complex is stable under 210 ℃.
基金supported by the Fund of Jiangsu Key Laboratory for Chemistry of Low-dimensional Materials (JSKC08047)Fund of Huanyin Teachers College (08HSJSK003)
文摘The ligand of N-（2-hydroxybenzylideneamino）-1,8-naphthalimide （HL） and its metal complexes of CuL2 （1） and CoL2 （2） have been synthesized. Elemental analysis, IR and X-ray single-crystal diffraction characterizations for 1 and 2 have been carried out. In the complexes of 1 and 2, the central metallic ions of Cu^2＋ and Co^2＋ coordinate with two deprotonated ligands of L-, respectively and adopt distorted square planar geometries. The thermal analysis result shows that the two complexes undergo two similar decomposition processes because of their similar geometric configurations. For the two complexes, fluorescence spectra measurements indicate that complex CoL2 emits stronger blue fluorescence than HL and the complex CuL2 does not emit fluorescence at all.
基金the financial support from the National Natural Science Foundation of China(No.21305056)open fund of State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics(No.T151402)
文摘The thermal stability of triple helical structure plays a critical role in collagen biosynthesis,function and degradation.CD technique was utilized to characterize the thermal stability of synthetic collagen mimic peptides.Fluorescence spectroscopy is widely used with easy access all around the world because of its inexpensive instrumentation,low operation cost,easy operation,and high sensitivity.Here we have developed an alternative fluorescence method to detect the thermal stability of collagen mimic peptides.We have demonstrated that fluorescence spectroscopy could measure the thermal stability of collagen mimic peptides with low concentrations under different circumstances.This highly sensitive fluorescence self-quenching assay will greatly expedite the studies of sequence-dependent properties of collagen mimic peptides,and it has great potential in the application of determining the thermal stability of triple helix systems such as collagens,collectins,adiponectin,macrophage scavenger and C1q.
基金This work was supported by the Scientific Research Project of Beijing Educational Committee(No.KM202010028007)。
文摘Nanocrystals(NCs)of cesium lead halide perovskites are optically unstable,which prevents their use in optical sensors.The combination of perovskite NCs and metal single atoms(SAs)may be a good solution to this issue.Unfortunately,depositing metal SAs on perovskite NCs remains a challenge due to relative weak metal-halide bonds.Herein,we present that,via a photo assisted method using cesium lead halide perovskite NCs as host material to anchor Y single atoms,we successfully synthesize Y SA anchored CsPbBr_(3)NCs(Y-SA/CsPbBr_(3)NCs)with outstanding fluorescence stability through the formation of two Y-O bonds and two Y-Br bonds.In comparison to bare CsPbBr_(3)NCs,Y-SA/CsPbBr_(3)NCs possess more stable optical characteristics.The as-synthesized Y-SA/CsPbBr_(3)NCs can be employed as a colorimetric platform to perform rapid CH_(3)I sensing.Detection limit of 0.044 ppm is exhibited in this approach with excellent anti-interference performance.The YSA/CsPbBr_(3)NCs-based system has been applied to the detection of CH_(3)I in sweet potato samples with satisfying results.
