UV-Vis spectrum and the third-order nonlinear optical properties of the chiral camphor-derived β-diketonate have been studied at the B3LYP/6-31G＊ level. The results showed that the introduction of electron-drawing g...UV-Vis spectrum and the third-order nonlinear optical properties of the chiral camphor-derived β-diketonate have been studied at the B3LYP/6-31G＊ level. The results showed that the introduction of electron-drawing group -CF3 and -C3F7 on β-diketonate made the strongest absorption peak red-shift and the lowest energy absorption blue-shied. Introduction of -OC2H5 on the benzene or pyridine ring made the lowest energy absorption blue-shift. When the -C2H3 was introduced on the benzene or pyridine ring, the lowest energy absorption was red-shifted. Introduction of electron-donating group on β-diketonate can enlarge their nonlinear optical properties. On the contrary, the introduction of electron-drawing group dropped it down.展开更多
In the present work, the molecular structures of two new synthesized dyes：（4,6-dimethylpyrimidin-2-ylamino）（5-p-tolylisoxazol-3-yl）methanol（PS-1） and N-（4,6-dimethylpyrimidin-2-yl）-5-phenylisoxazole-3-carboxa...In the present work, the molecular structures of two new synthesized dyes：（4,6-dimethylpyrimidin-2-ylamino）（5-p-tolylisoxazol-3-yl）methanol（PS-1） and N-（4,6-dimethylpyrimidin-2-yl）-5-phenylisoxazole-3-carboxamide（PS-2）, have been investigated using density functional theory（DFT） in dimethylformamide（DMF） for the first time. The electronic spectra of new dyes in a DMF solvent were carried out by time dependent density functional theory（TD-DFT） method. After quantum-chemical calculations two new dyes for the optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. NucleusIndependent Chemical Shifts（NICS） calculations have also been carried out for the title compounds. The computed absorption spectral data of the title compounds are in good agreement with the experimental data, thus allowing an assignment of the UV spectra. The HOMO and LUMO molecular orbitals, excitation energies and oscillator strengths for the dyes have also been calculated and presented.展开更多
The opticai properties of C,, chemicaiiy modified poiystyrene(C,, -PS copolymer) and the parent polystyrene (PS) films have been investigated.Addition of bulky C,, moiety, a special functional group, to the polystyren...The opticai properties of C,, chemicaiiy modified poiystyrene(C,, -PS copolymer) and the parent polystyrene (PS) films have been investigated.Addition of bulky C,, moiety, a special functional group, to the polystyrene by anovel organometallic reaction modified considerably the optical property of theparent polystyrene. The lattice periodicity of pure PS film is subject to someperturbation or distortion in varying degrees due to the covalent attachInent of bulkyC,, moiety to the polymer backbone. C,,-PS copolymer possesses a new energy ba-ndstructure with indirect forbidden band when compared with the parent PS.展开更多
Three new 2D metal-organic frameworks, [M（BIDPE）2（bdc）2]n（M = Co for 1, Ni for 2） and [Ni（PIDPE）2（H2O）2（bdc）]n（3）（BIDPE = 4,4A-bis（imidazol-1-yl） diphenyl ether, PIDPE =4-（pyridyl）-4A-（imidazol-1-y...Three new 2D metal-organic frameworks, [M（BIDPE）2（bdc）2]n（M = Co for 1, Ni for 2） and [Ni（PIDPE）2（H2O）2（bdc）]n（3）（BIDPE = 4,4A-bis（imidazol-1-yl） diphenyl ether, PIDPE =4-（pyridyl）-4A-（imidazol-1-yl） diphenyl ether, bdc2- = 1,3-benzenedicarboxylate）, were characterized by single-crystal X-ray diffraction, elemental analysis, PXRD, IR spectroscopy and TGA analysis.Complex 1 crystallizes in monoclinic, space group P21/n, with a = 9.1568（12）, b = 16.943（2）, c =15.441（2） A, β = 104.049（2）°, V = 2323.9（5） A^3, Dc = 1.420 g/cm^3, Mr = 993.83, F（000） = 1026, μ =0.440 mm-（-1） and Z = 2. Complex 2 crystallizes in monoclinic, space group P21/n, with a =9.1395（17）, b = 17.019（3）, c = 15.473（3） A, β = 104.651（2）°, V = 2328.5（7） A^3, Dc = 1.414 g/cm^3,Mr = 991.58, F（000） = 1024, μ = 0.487 mm^-1, Z = 2. Complex 3 also belongs to the monoclinic system, space group P21/n, with a = 11.4365（16）, b = 18.346（3）, c = 11.7068（17） A, β = 91.022（2）°,V = 2455.9（6） A3, Dc = 1.422 g/cm^3, Mr = 1051.66, F（000） = 1092, μ = 0.468 mm^-1, Z = 2. All complexes 1, 2 and 3 are 2D layer structures constructed from intermolecular hydrogen bonds. In addition, the solid UV-vis properties of complexes 1, 2 and 3 were also studied.展开更多
Rocky desertification has become a major environmental issue in the karst region of southwestern China.Karst rocky desertification was more severe in regions of limestone soil than in adjacent regions of other soils,d...Rocky desertification has become a major environmental issue in the karst region of southwestern China.Karst rocky desertification was more severe in regions of limestone soil than in adjacent regions of other soils,despite the relatively higher soil organic matter(SOM)content in limestone soil.The underlying mechanism remains ambiguous.We speculated that the geochemical characteristics of limestone soils in the karst region plays an essential role,especially the high calcium content of limestone soil.To test this hypothesis,we collected limestone soil samples from a limestone soil profile in the southwestern China karst region and extracted humic acid(HA)from these limestone soil samples.We investigated the interaction of Ca^(2+)and three HA samples on a joint experimental platform,which consists of an automatic potentiometric titrator,a UV–visible spectrometer,and a Fluorescence spectrometer.HA solutions were titrated by Ca^(2+)and optical spectra of the HA solutions were monitored during the titration experiments.The results indicated that:(1)the interaction of Ca^(2+)and HA is a combined process of adsorption and complexation.Adsorption dominated the overall distribution behavior of Ca^(2+),which could be fit by Langmuir and Freundlich isotherm models.Complexation was distinguished only when the concentration of Ca2+is low;(2)the changes of UV–visible spectroscopy and excitation–emission matrix fluorescencespectroscopy spectra of HA samples when they were binding with Ca^(2+)implied the apparent molecular size and structure of HA became larger and more complex;(3)the combination of Ca^(2+)and HA plays an important role in the SOM preservation of limestone soils but the stability of the Ca–HA association was relatively weak.The present study draws attention to maintaining the relatively higher Ca^(2+)concentration in limestone soils in ecologic restoration attempts in karst regions.展开更多
A new coordination polymer [Cu2(OH)(nbta)(tib)(H2 O)2]n(1, H3 nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, tib = 1-(4 H-1,2,4-triazol-4-yl)-4-(imidazol-1-yl)benzene) constructed from dimeric Cu(Ⅱ) units has been s...A new coordination polymer [Cu2(OH)(nbta)(tib)(H2 O)2]n(1, H3 nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, tib = 1-(4 H-1,2,4-triazol-4-yl)-4-(imidazol-1-yl)benzene) constructed from dimeric Cu(Ⅱ) units has been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analysis. The compound crystallizes in monoclinic system, space group I2/c, with a = 17.8474(9), b = 11.7588(6), c = 21.9221(11) ?, β = 104.419(5)°, V = 4455.7(4) ?3 and Z = 8. Compound 1 is a three-dimensional structure constructed from dimeric Cu(Ⅱ) units and presents a 2-nodal(3,5)-connected net. Moreover, the thermal stability and solid UV-Vis absorption spectra have been investigated.展开更多
基金supported by the National Natural Science Foundation of China(21172161)
文摘UV-Vis spectrum and the third-order nonlinear optical properties of the chiral camphor-derived β-diketonate have been studied at the B3LYP/6-31G＊ level. The results showed that the introduction of electron-drawing group -CF3 and -C3F7 on β-diketonate made the strongest absorption peak red-shift and the lowest energy absorption blue-shied. Introduction of -OC2H5 on the benzene or pyridine ring made the lowest energy absorption blue-shift. When the -C2H3 was introduced on the benzene or pyridine ring, the lowest energy absorption was red-shifted. Introduction of electron-donating group on β-diketonate can enlarge their nonlinear optical properties. On the contrary, the introduction of electron-drawing group dropped it down.
基金supported by the National Academy of Sciences of Belarus
文摘In the present work, the molecular structures of two new synthesized dyes：（4,6-dimethylpyrimidin-2-ylamino）（5-p-tolylisoxazol-3-yl）methanol（PS-1） and N-（4,6-dimethylpyrimidin-2-yl）-5-phenylisoxazole-3-carboxamide（PS-2）, have been investigated using density functional theory（DFT） in dimethylformamide（DMF） for the first time. The electronic spectra of new dyes in a DMF solvent were carried out by time dependent density functional theory（TD-DFT） method. After quantum-chemical calculations two new dyes for the optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. NucleusIndependent Chemical Shifts（NICS） calculations have also been carried out for the title compounds. The computed absorption spectral data of the title compounds are in good agreement with the experimental data, thus allowing an assignment of the UV spectra. The HOMO and LUMO molecular orbitals, excitation energies and oscillator strengths for the dyes have also been calculated and presented.
基金the National Natural Science Foundation of China(5117214451372153)+2 种基金Science Technology Foundation of shanghai(12410710300)Leading Academic Discipline Project of Shanghai Municipal Education Commission(J51503)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning
文摘The opticai properties of C,, chemicaiiy modified poiystyrene(C,, -PS copolymer) and the parent polystyrene (PS) films have been investigated.Addition of bulky C,, moiety, a special functional group, to the polystyrene by anovel organometallic reaction modified considerably the optical property of theparent polystyrene. The lattice periodicity of pure PS film is subject to someperturbation or distortion in varying degrees due to the covalent attachInent of bulkyC,, moiety to the polymer backbone. C,,-PS copolymer possesses a new energy ba-ndstructure with indirect forbidden band when compared with the parent PS.
基金supported by the Natural Science Foundation of China(21301005)Natural Science Foundation of Anhui Province(1408085QB31)
文摘Three new 2D metal-organic frameworks, [M（BIDPE）2（bdc）2]n（M = Co for 1, Ni for 2） and [Ni（PIDPE）2（H2O）2（bdc）]n（3）（BIDPE = 4,4A-bis（imidazol-1-yl） diphenyl ether, PIDPE =4-（pyridyl）-4A-（imidazol-1-yl） diphenyl ether, bdc2- = 1,3-benzenedicarboxylate）, were characterized by single-crystal X-ray diffraction, elemental analysis, PXRD, IR spectroscopy and TGA analysis.Complex 1 crystallizes in monoclinic, space group P21/n, with a = 9.1568（12）, b = 16.943（2）, c =15.441（2） A, β = 104.049（2）°, V = 2323.9（5） A^3, Dc = 1.420 g/cm^3, Mr = 993.83, F（000） = 1026, μ =0.440 mm-（-1） and Z = 2. Complex 2 crystallizes in monoclinic, space group P21/n, with a =9.1395（17）, b = 17.019（3）, c = 15.473（3） A, β = 104.651（2）°, V = 2328.5（7） A^3, Dc = 1.414 g/cm^3,Mr = 991.58, F（000） = 1024, μ = 0.487 mm^-1, Z = 2. Complex 3 also belongs to the monoclinic system, space group P21/n, with a = 11.4365（16）, b = 18.346（3）, c = 11.7068（17） A, β = 91.022（2）°,V = 2455.9（6） A3, Dc = 1.422 g/cm^3, Mr = 1051.66, F（000） = 1092, μ = 0.468 mm^-1, Z = 2. All complexes 1, 2 and 3 are 2D layer structures constructed from intermolecular hydrogen bonds. In addition, the solid UV-vis properties of complexes 1, 2 and 3 were also studied.
基金supported by the National Natural Science Foundation of China (U1701241, U1612441,41773147, and 41273149)the Science Foundation of Guizhou(20113109) 。
文摘Rocky desertification has become a major environmental issue in the karst region of southwestern China.Karst rocky desertification was more severe in regions of limestone soil than in adjacent regions of other soils,despite the relatively higher soil organic matter(SOM)content in limestone soil.The underlying mechanism remains ambiguous.We speculated that the geochemical characteristics of limestone soils in the karst region plays an essential role,especially the high calcium content of limestone soil.To test this hypothesis,we collected limestone soil samples from a limestone soil profile in the southwestern China karst region and extracted humic acid(HA)from these limestone soil samples.We investigated the interaction of Ca^(2+)and three HA samples on a joint experimental platform,which consists of an automatic potentiometric titrator,a UV–visible spectrometer,and a Fluorescence spectrometer.HA solutions were titrated by Ca^(2+)and optical spectra of the HA solutions were monitored during the titration experiments.The results indicated that:(1)the interaction of Ca^(2+)and HA is a combined process of adsorption and complexation.Adsorption dominated the overall distribution behavior of Ca^(2+),which could be fit by Langmuir and Freundlich isotherm models.Complexation was distinguished only when the concentration of Ca2+is low;(2)the changes of UV–visible spectroscopy and excitation–emission matrix fluorescencespectroscopy spectra of HA samples when they were binding with Ca^(2+)implied the apparent molecular size and structure of HA became larger and more complex;(3)the combination of Ca^(2+)and HA plays an important role in the SOM preservation of limestone soils but the stability of the Ca–HA association was relatively weak.The present study draws attention to maintaining the relatively higher Ca^(2+)concentration in limestone soils in ecologic restoration attempts in karst regions.
基金supported by the National Natural Science Foundation of China(21401097)
文摘A new coordination polymer [Cu2(OH)(nbta)(tib)(H2 O)2]n(1, H3 nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, tib = 1-(4 H-1,2,4-triazol-4-yl)-4-(imidazol-1-yl)benzene) constructed from dimeric Cu(Ⅱ) units has been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analysis. The compound crystallizes in monoclinic system, space group I2/c, with a = 17.8474(9), b = 11.7588(6), c = 21.9221(11) ?, β = 104.419(5)°, V = 4455.7(4) ?3 and Z = 8. Compound 1 is a three-dimensional structure constructed from dimeric Cu(Ⅱ) units and presents a 2-nodal(3,5)-connected net. Moreover, the thermal stability and solid UV-Vis absorption spectra have been investigated.
