The structures of 2,7'-(ethylene)-bis-8-hydroxyquinoline and its derivatives were optimized at the ground states using ab initio HF and B3LYP methods. At the same time, the molecular structures of the first singlet...The structures of 2,7'-(ethylene)-bis-8-hydroxyquinoline and its derivatives were optimized at the ground states using ab initio HF and B3LYP methods. At the same time, the molecular structures of the first singlet excited state for 2,7'-(ethylene)-bis-8-hydroxyqulnoline and its derivatives were optimized by CIS/6-31G(d). The absorption and emission spectra based on the above structures were obtained by the time-dependent density functional theory (TD-DFT) by the B3LYP method with the 6-31G(d) basis set. The calculated results of luminescence originate from the electronic transition from the hydroxphenol ring of 8-hydroxyquinoline A to the pyridine ring of 8-hydroxyquinoline B. Their luminescence wave bands can be tuned by different substituents on the ligand of 8-hydroxyquinoline.展开更多
The protection influence of 8-hydroxy-7-quinolinecarboxaldehyde derivatives against C-steel corrosion was studied in 2 mol·L^(-1)HCl solutions at 30 °C. Measurements were conducted under various experimental...The protection influence of 8-hydroxy-7-quinolinecarboxaldehyde derivatives against C-steel corrosion was studied in 2 mol·L^(-1)HCl solutions at 30 °C. Measurements were conducted under various experimental conditions using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy(EIS) and electrochemical frequency modulation(EFM) techniques. These studies have shown that 8-hydroxy-7-quinolinecarboxaldehyde derivatives are very good "green", mixed-type inhibitors. Corrosion rates obtained from both EFM and EIS methods are comparable with those recorded using Tafel extrapolation method, confirming validation of corrosion rates measured by the latter. The inhibitive action of these 8-hydroxy-7-quinolinecarboxaldehyde derivatives was discussed in terms of blocking the electrode surface by adsorption of the molecules through the active centers contained in their structures following Langmuir adsorption isotherm. Quantum chemical method was also employed to explore the relationship between the inhibitor molecular properties and its protection efficiency.展开更多
The enzymatic synthesis of CCK-8 tripeptide derivative Phac-Met-Asp(OMe)-Phe-NH2 is reported. Starting with Phac-Met-OCam, we have successfully synthesized the target tripeptide with three free or immobilized enzymes...The enzymatic synthesis of CCK-8 tripeptide derivative Phac-Met-Asp(OMe)-Phe-NH2 is reported. Starting with Phac-Met-OCam, we have successfully synthesized the target tripeptide with three free or immobilized enzymes, ?chymotrypsin, papain and thermolysin in reasonable yields. The key steps in this synthesis were the coupling of Phac-Met-OCam and H-Asp(OMe)2 to form Met-Asp peptide bond catalyzed by ?chymotrypsin and the selective hydrolysis of -ester of Phac-Met-Asp(OMe)2 catalyzed by papain.展开更多
The synthesis and crystal structure of a novel calix[8]arene ester are reported herein. The calix[8]arene ester derivative has been characterized by IR, NMR and X-ray crystal analysis. The X-ray structure analysis r...The synthesis and crystal structure of a novel calix[8]arene ester are reported herein. The calix[8]arene ester derivative has been characterized by IR, NMR and X-ray crystal analysis. The X-ray structure analysis revealed that the 8 phenolic hydroxy groups of the calix[8]arene have been substituted by 4 diethyl dibromomalonate molecules with each two adjacent hydroxy oxygen atoms attached to a bridge diethyl malonate.展开更多
The novel linear, circular, hooped, and helical molecules based on oligo[8]thio- phene were theoretically studied for the applications of charge transfer devices. To investigate the influence of topology for oligo[8]t...The novel linear, circular, hooped, and helical molecules based on oligo[8]thio- phene were theoretically studied for the applications of charge transfer devices. To investigate the influence of topology for oligo[8]thiophene derivatives, the geometry structures, frontier molecular orbital (FMO) energies, charge transport properties, and stability property were predicted by density functional theory methods. The calculated results reported herein show that the oligo[8]thiophene derivative with linear structure has smaller energy gap, and fused oligo[8]thiophene derivative with circular structure has the smallest reorganization energy among the designed molecules. We have also studied the stability properties of the designed molecules, and oligo[8]thiophene derivatives are more stable tharJ the fused oligo[8]thiophene derivatives.展开更多
The chlorination of S-alkyl(aryl) 0,0-dialkyl dithiophosphates with phosphorus oxychloride proceeds with isomerization to give S-alkyl S'-alkyl(aryl) dithiophosphorochtoridates, which react further with various nu...The chlorination of S-alkyl(aryl) 0,0-dialkyl dithiophosphates with phosphorus oxychloride proceeds with isomerization to give S-alkyl S'-alkyl(aryl) dithiophosphorochtoridates, which react further with various nucleophiles in the presence of base to give the title compounds展开更多
The molecular geometries, frontier molecular orbital properties, and absorption and emission properties of three 4-phenoxy-1,8-naphthalimide derivatives, namely 4-phenoxy-N-(2-hydroxyethyl)-1,8-naphthalimide(1),4-...The molecular geometries, frontier molecular orbital properties, and absorption and emission properties of three 4-phenoxy-1,8-naphthalimide derivatives, namely 4-phenoxy-N-(2-hydroxyethyl)-1,8-naphthalimide(1),4-(2-tert-butylphenoxy)-N-(2-hydroxyethyl)-1,8-naphthalimide(2), and 4-[2,4-di(tert-butyl)]phenoxy-N-(2-hydroxyethyl)-1,8-naphthalimide(3), are investigated by density functional theory(DFT) and time-dependent density functional theory(TD-DFT) calculations in conjunction with polarizable continuum models(PCMs). Four functionals and ten basis sets are employed for 1 to calculate the electron transition energies, which were compared with the experimental observations. Our results reveal that the B3LYP/6-311+G(d,p) method is the best choice to reproduce the experimental spectra. Moreover, the effects of substituents on the molecular geometries, electronic structures, absorption and emission spectra are also studied at the B3LYP/6-311+G(d,p) level. We find that the gap between the highest occupied molecular orbital(HOMO) and the lowest unoccupied molecular orbital(LUMO) decreases with increasing the number of tert-butyl substituents onto the phenoxy groups, suggesting red-shift of the absorption and emission bands. This is related to the increase of conjugation from 1 to 2 and 3. Our calculations are in good agreement with the experimental results.展开更多
In situ thickness dependent photoluminescence (PL) measurements of tris(8-hydroxyquinoline) aluminum(Alq3) film were performed. At the beginning of Alq3 deposition on the glass substrate, the Alq3 emission showe...In situ thickness dependent photoluminescence (PL) measurements of tris(8-hydroxyquinoline) aluminum(Alq3) film were performed. At the beginning of Alq3 deposition on the glass substrate, the Alq3 emission showed a sharp red-shift. Further deposition of Alq3 resulted slight red-shift, and finally tended to saturated value. The total red-shift of about 12 nm was observed for the Alq3 film thickness range from 2 to 500 nm.This red-shift was attributed to the change from the 2D to 3D exciton state with increasing Alq3 film thickness. Meanwhile, the PL intensity of Alq3 emission increased continuously, and showed a rate change at the initial deposition of Alq3 due to non-rediative decay of excitons arised from the interaction between excitons and the substrate, and finally tended to saturation with the Alq3 thickness.展开更多
The coordination complex Sm(C7H5O2)2·(C9H6NO), synthesized from the reaction of samarium chloride sixhydrate with salicylic acid and 8-hydroxyquinoline, was characterized with IR, elemental analysis, molar co...The coordination complex Sm(C7H5O2)2·(C9H6NO), synthesized from the reaction of samarium chloride sixhydrate with salicylic acid and 8-hydroxyquinoline, was characterized with IR, elemental analysis, molar conductance, and thermogravimatric analysis. The standard molar enthalpies of solution of [ SmCl3·6H2O (s) ], [ 2C7H6O3 (s) ], [ C9H7NO ( s ) ] and [ Sm (C7H5O3) 2·( C9H6NO ) ( s ) ] in the calorimetric solvent were determined with the solution-reaction isoperibol calorimeter at 298.15 K to be △sHm^- [ SmCl3·6H2O (s), 298.15 K ] = - 103.98 ± 0.04 kJ·mol^-1, △sHm^- [2 C7H6O3 (s), 298.15 K] = 16.35±0.14 kJ·mol^-1,△sHm^-[C9H7NO (s), 298.15 K] = -6.11±0.08 kJ·mol^-1 and △sHm^-[Sm(C7H5O3)2·(C9H6NO) (s), 298.15 K] = - 130.08 ± 0.04 kJ·mol^-1, respectively. The enthalpy was determined to be △rHm^- = 89.59 ±0.18 kJ·mol^-1 for the reaction SmCl3·6H2O(s) + 2C7H6O3(s) + C9H7NO(s) = Sm (C7H5O3) 2·(C9H6NO) ( s ) + 3HCl (g) + 6H2O ( l ). According to the above results and the data given in literature and through Hess' law, the standard molar enthalpy of formation of Sin( C7H5O3 )2·(C9H7NO)(s) was estimated to be △rHm^- [ Sm (C7H5O3)2·(C9H6NO) (s), 298.15 K] = - 2055.9 ± 3.03 kJ·mol^-1.展开更多
Fluorescent mesoporous silica nanoparticles functionalized with carboxyl group(Znq-CMSCOOH) were successfully synthesized by in situ formation route of 8-hydroxyquinolinate zinc complexes in channels of mesoporous sil...Fluorescent mesoporous silica nanoparticles functionalized with carboxyl group(Znq-CMSCOOH) were successfully synthesized by in situ formation route of 8-hydroxyquinolinate zinc complexes in channels of mesoporous silica nanoparticles and post-grafting of carboxyl group on the surface. Moreover,the particle size and structural properties of Znq-CMS-COOH were characterized by transmission electron microscopy(TEM),field emission scanning electron microscopy(FE-SEM),dynamic light scattering(DLS),Fourier transform infrared spectroscopy(FT-IR),UV-vis spectrometer, fluorescence spectrometer and nitrogen adsorption-desorption measurements. The obtained results suggest that the Znq-CMS-COOH presents the uniform spherical shape with the mean diameter of about 85 nm and the obvious wormhole arrangement mesoporous. In addition, the Znq-CMS-COOH possesses green fluorescence with the emission peaks at 495 nm. So the Znq-CMS-COOH, which is beneficial to further modification and tracing, might be a great potential carrier for applying in drug delivery system in the future.展开更多
The structure of a binuclear cadmium(Ⅱ) quaternary complex, [Cd2(phen)2- Q2(BP)]n 1 (phen = 1,10-phenanthroline, BP = biphenyl-4,4′-dicarboxylic acid, Q = 8-hydroxy- quinoline-anion), has been determined by ...The structure of a binuclear cadmium(Ⅱ) quaternary complex, [Cd2(phen)2- Q2(BP)]n 1 (phen = 1,10-phenanthroline, BP = biphenyl-4,4′-dicarboxylic acid, Q = 8-hydroxy- quinoline-anion), has been determined by X-ray crystallography and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. It crystallizes in the monoclinic system, space group P21/n with a = 13.1906(18), b = 10.9623(15), c = 16.947(2)A, β = 111.3430(10)°, V = 2282.5(5)A^3, Z = 4, Mr = 556.85, Dc = 1.620 g/cm^3, F(000) = 1116,μ= 0.994 mm^-1 and S = 1.056. In the structure, 1D chains are connected via biphenyl-4,4′-dicarboxylic acid, 8-hydroxy quinoline anion and binuclear cadmium atoms into an infinite 1-D molecular chain architecture. Via aryl ring π-π stacking interactions a supramolecular structure is formed in 1.展开更多
The synergistic extraction of Pr^3+ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester (P507, HL) and 8-Hydroxyquinoline (HQ) in heptane was investigated. The effect o...The synergistic extraction of Pr^3+ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester (P507, HL) and 8-Hydroxyquinoline (HQ) in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr^3+ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration oil extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr^3+.展开更多
Chronic exposure to coplanar polychlorinated biphenyls(PCBs),a potent inducer of toxic reactive oxygen species(ROS),in the environment and food can cause liver diseases.It remains unknown whether caffeic acid deri...Chronic exposure to coplanar polychlorinated biphenyls(PCBs),a potent inducer of toxic reactive oxygen species(ROS),in the environment and food can cause liver diseases.It remains unknown whether caffeic acid derivatives(CADs) exerted protective effect on PCB-induced hepatotoxicity.We sought to evaluate the activities of 3CADs on PCB169-induced oxidative stress and DNA damage in the liver.Male ICR mice were administered with1 μmol/mL PCB169 at 5 mL/kg body weight for 2 weeks.The mice were given CADs by gastric gavage for 3weeks.We found that PCB169 decreased the growth rate and reduced the levels of superoxide dismutase(SOD),glutathione(GSH) and GSH peroxidase(GPx).It increased the liver weight,malondialdehyde(MDA)and 8-hydroxy-2'-deoxyguanosine(8-OHdG) levels and CYPlAl activity in the liver tissues and plasma of mice(P〈0.05).Pretreatment of mice with CADs restored the above parameters to normal levels.There was a synergistic protective effect between CADs in preventing MDA and 8-OHdG formation and inducing CYPlAl and phase II metabolism enzyme(SOD,GPx) activities(P〈0.05).In conclusion,PCB169 induced hepatotoxicity and pretreatment with CADs had synergistic protective effects on liver damage.展开更多
Pigment epithelium-derived factor (PEDF) is an antiangiogenic factor which is effective in tumour inhibition in a variety of tumours and has not yet been studied in bladder tumour before. In this study the expressio...Pigment epithelium-derived factor (PEDF) is an antiangiogenic factor which is effective in tumour inhibition in a variety of tumours and has not yet been studied in bladder tumour before. In this study the expression of PEDF, interleukin-1α (IL-1α) and -8 (IL-8) in bladder tumours was investigated. Immunohistochemistry was performed on 64 bladder tumour and 23 normal uroepithelium samples. Expression change of the factors was compared with clinicopathological parameters. Correlations between PEDF, IL-1α and IL-8 were analyzed. None of the factors was in relation to gender, tumour occurrence, and size or onset pattern. PEDF (P=0.014) and IL-1α (P=0.049) expression was down-regulated with grade progression. PEDF expression was lower in normal uroepithelium than in papillary urothelial neoplasm of low malignant potential (PUNLMP) (P=0.000) and carcinoma (P=0.009) whilst IL-1α (P=0.000 and P=0.000 respectively) and IL-8 (P=0.000 and P=0.023 respectively) expression was higher in the same grouping. PEDF expression had a negative correlation with IL-8 in PUNLMP (P=0.049, r=-0.578) as well as in tumour grouping (P=0.033, r=-0.276). Deranged expressional change of PEDF, IL-1α and IL-8 could be in relation to loss of differentiation from normal uroepithelium to papillary lesion and eventually to carcinoma.展开更多
Stable and persistent bipolar resistive switching was observed in an organic diode with the structure of indium-tin oxide (ITO)/bis(8-hydroxyquinoline) cadmium (Cdq2)/Al. Aggregate formation and electric field d...Stable and persistent bipolar resistive switching was observed in an organic diode with the structure of indium-tin oxide (ITO)/bis(8-hydroxyquinoline) cadmium (Cdq2)/Al. Aggregate formation and electric field driven trapping and detrapping of charge carriers in the aggregate states that lie in the energy gap of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the organic molecule were proposed as the mechanism of the observed bipolar resistive switching, and this was solidly supported by the results of AFM investigations. Repeatedly set, read, and reset measurements demonstrated that the device is potentially applicable in non-volatile memories.展开更多
8-Hydroxyquinoline salt of pyrazine-2,3,5,6-tetracarboxylic acid [HQ]2[H2pztc]· 2H2O (1) was prepared and characterized by single-crystal X-ray diffraction, NMR, IR, TGA, elemental analysis and fluorescent meas...8-Hydroxyquinoline salt of pyrazine-2,3,5,6-tetracarboxylic acid [HQ]2[H2pztc]· 2H2O (1) was prepared and characterized by single-crystal X-ray diffraction, NMR, IR, TGA, elemental analysis and fluorescent measurements. Compound 1 crystallizes in orthorhombic, space group Pbcn with a = 9.953(3), b = 15.966(3), c = 16.081(5) A, V = 2555.5(13) A3, Z = 4, μ = 0.122 mm^-1, Dc = 1.514 Mg/m3, T= 296(2) K, C26H22N4O12, Mr = 582.48, F(000) = 1208, S = 1.006, R = 0.0448 and wR = 0.1149. Compound 1 has a three-dimensional (3D) network, in which pyra- zine-2,3,5,6-tetracarboxylic acids build up two-dimensional (2D) sheets and 8-hydroxyquinoline cations and water molecules act as pillars to connect the 2D sheets into an extended 3D network through strong intermolecular hydrogen bonding and π…π stacking interactions. Especially, a very short O-H…O hydrogen bond (O…O 2.470(2) A) between two neighboring [H2pztc] anions was observed.展开更多
2,7′-(Ethylene)-bis-8-hydroxyquinoline was optimized with DFT/B3LYP and ab initio HF methods, so ion- ization potential and electron affinity could be determined. Absorption spectrum was calculated by ZINDO and TD-...2,7′-(Ethylene)-bis-8-hydroxyquinoline was optimized with DFT/B3LYP and ab initio HF methods, so ion- ization potential and electron affinity could be determined. Absorption spectrum was calculated by ZINDO and TD-DFT. CIS method was used to calculate the S1 excited states of the compound and afterwards the emission spectrum was computed. When the solvent effect was taken into account, the computed results show encouraging agreement with known experimental data. The results of analyzing the relationship between the energies and absorption spectra indicate that the ability to transporting electrons is strengthened compared with 8-hydroxyquinoline and that absorption and emission spectra are red-shifted. The intramoleeular reor- ganization energy of tris(2,7′-(ethylene)-bis-8-hydroxyquinoline)-aluminum implies its electron transporting property is worse than tris(8-hydroxyquinoline)-aluminum. The predicted maximum emission wavelength is red-shifted compared with tris(8-hydroxyquinoline)-aluminum.展开更多
The single crystal of bi(8-hydroxyquinoline) bihydrated cobalt (Ⅱ) complex, [ Co(Q)2 (H2O2 ] (Q = 8-hydroxyquinoline ion), has been synthesized by general method and structurally characterized by single crys...The single crystal of bi(8-hydroxyquinoline) bihydrated cobalt (Ⅱ) complex, [ Co(Q)2 (H2O2 ] (Q = 8-hydroxyquinoline ion), has been synthesized by general method and structurally characterized by single crystal X-ray diffraction. Crystal data: C18H16CoN2O4, monoclinic, C2/c, α = 1.336 2(4) nm, b = 0.941 2(3) nm, c = 1.354 3(4) nm, β= 109.672(4)°, Z = 4. In the complex, Co( Ⅱ ) ion is six-coordinated, forming a distorted octahedron. H-bonding and π-π stacking interaction play a significant role to form and stabilize the three-dimensional structure.展开更多
基金Supported by the Foundation of Education Committee of Gansu Province (No. 0708-11)foundation of Tianshui Normal University (No. TSA0604)
文摘The structures of 2,7'-(ethylene)-bis-8-hydroxyquinoline and its derivatives were optimized at the ground states using ab initio HF and B3LYP methods. At the same time, the molecular structures of the first singlet excited state for 2,7'-(ethylene)-bis-8-hydroxyqulnoline and its derivatives were optimized by CIS/6-31G(d). The absorption and emission spectra based on the above structures were obtained by the time-dependent density functional theory (TD-DFT) by the B3LYP method with the 6-31G(d) basis set. The calculated results of luminescence originate from the electronic transition from the hydroxphenol ring of 8-hydroxyquinoline A to the pyridine ring of 8-hydroxyquinoline B. Their luminescence wave bands can be tuned by different substituents on the ligand of 8-hydroxyquinoline.
文摘The protection influence of 8-hydroxy-7-quinolinecarboxaldehyde derivatives against C-steel corrosion was studied in 2 mol·L^(-1)HCl solutions at 30 °C. Measurements were conducted under various experimental conditions using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy(EIS) and electrochemical frequency modulation(EFM) techniques. These studies have shown that 8-hydroxy-7-quinolinecarboxaldehyde derivatives are very good "green", mixed-type inhibitors. Corrosion rates obtained from both EFM and EIS methods are comparable with those recorded using Tafel extrapolation method, confirming validation of corrosion rates measured by the latter. The inhibitive action of these 8-hydroxy-7-quinolinecarboxaldehyde derivatives was discussed in terms of blocking the electrode surface by adsorption of the molecules through the active centers contained in their structures following Langmuir adsorption isotherm. Quantum chemical method was also employed to explore the relationship between the inhibitor molecular properties and its protection efficiency.
文摘The enzymatic synthesis of CCK-8 tripeptide derivative Phac-Met-Asp(OMe)-Phe-NH2 is reported. Starting with Phac-Met-OCam, we have successfully synthesized the target tripeptide with three free or immobilized enzymes, ?chymotrypsin, papain and thermolysin in reasonable yields. The key steps in this synthesis were the coupling of Phac-Met-OCam and H-Asp(OMe)2 to form Met-Asp peptide bond catalyzed by ?chymotrypsin and the selective hydrolysis of -ester of Phac-Met-Asp(OMe)2 catalyzed by papain.
基金We are grateful to the Nationa]Natural Science Foundation of China for the support of this work(grant No.29771005)
文摘The synthesis and crystal structure of a novel calix[8]arene ester are reported herein. The calix[8]arene ester derivative has been characterized by IR, NMR and X-ray crystal analysis. The X-ray structure analysis revealed that the 8 phenolic hydroxy groups of the calix[8]arene have been substituted by 4 diethyl dibromomalonate molecules with each two adjacent hydroxy oxygen atoms attached to a bridge diethyl malonate.
基金Supported by the National Natural Science Foundation of China(No.21302062)the Science Foundation for Young Teachers of Jilin Agricultural University(No.201219)
文摘The novel linear, circular, hooped, and helical molecules based on oligo[8]thio- phene were theoretically studied for the applications of charge transfer devices. To investigate the influence of topology for oligo[8]thiophene derivatives, the geometry structures, frontier molecular orbital (FMO) energies, charge transport properties, and stability property were predicted by density functional theory methods. The calculated results reported herein show that the oligo[8]thiophene derivative with linear structure has smaller energy gap, and fused oligo[8]thiophene derivative with circular structure has the smallest reorganization energy among the designed molecules. We have also studied the stability properties of the designed molecules, and oligo[8]thiophene derivatives are more stable tharJ the fused oligo[8]thiophene derivatives.
基金This project was supported by National Natrural Science Foundation of China.
文摘The chlorination of S-alkyl(aryl) 0,0-dialkyl dithiophosphates with phosphorus oxychloride proceeds with isomerization to give S-alkyl S'-alkyl(aryl) dithiophosphorochtoridates, which react further with various nucleophiles in the presence of base to give the title compounds
基金supported by the Scientific Research Fund of Hubei Provincial Education Department(No.Q20122909)the Open Fund of Key Laboratory of Biologic Resources Protection and Utilization of Hubei Province(No.PKLHB1314)the First-class Discipline of Forestry in Hubei Minzu University
文摘The molecular geometries, frontier molecular orbital properties, and absorption and emission properties of three 4-phenoxy-1,8-naphthalimide derivatives, namely 4-phenoxy-N-(2-hydroxyethyl)-1,8-naphthalimide(1),4-(2-tert-butylphenoxy)-N-(2-hydroxyethyl)-1,8-naphthalimide(2), and 4-[2,4-di(tert-butyl)]phenoxy-N-(2-hydroxyethyl)-1,8-naphthalimide(3), are investigated by density functional theory(DFT) and time-dependent density functional theory(TD-DFT) calculations in conjunction with polarizable continuum models(PCMs). Four functionals and ten basis sets are employed for 1 to calculate the electron transition energies, which were compared with the experimental observations. Our results reveal that the B3LYP/6-311+G(d,p) method is the best choice to reproduce the experimental spectra. Moreover, the effects of substituents on the molecular geometries, electronic structures, absorption and emission spectra are also studied at the B3LYP/6-311+G(d,p) level. We find that the gap between the highest occupied molecular orbital(HOMO) and the lowest unoccupied molecular orbital(LUMO) decreases with increasing the number of tert-butyl substituents onto the phenoxy groups, suggesting red-shift of the absorption and emission bands. This is related to the increase of conjugation from 1 to 2 and 3. Our calculations are in good agreement with the experimental results.
基金This work is supported by the National Natural Science Foundation of China (No. 10274072, 20240430654)the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20030335017).
文摘In situ thickness dependent photoluminescence (PL) measurements of tris(8-hydroxyquinoline) aluminum(Alq3) film were performed. At the beginning of Alq3 deposition on the glass substrate, the Alq3 emission showed a sharp red-shift. Further deposition of Alq3 resulted slight red-shift, and finally tended to saturated value. The total red-shift of about 12 nm was observed for the Alq3 film thickness range from 2 to 500 nm.This red-shift was attributed to the change from the 2D to 3D exciton state with increasing Alq3 film thickness. Meanwhile, the PL intensity of Alq3 emission increased continuously, and showed a rate change at the initial deposition of Alq3 due to non-rediative decay of excitons arised from the interaction between excitons and the substrate, and finally tended to saturation with the Alq3 thickness.
基金Project supported by the Hunan Provincial Natural Sciences Foundation of China (03JJY3019)
文摘The coordination complex Sm(C7H5O2)2·(C9H6NO), synthesized from the reaction of samarium chloride sixhydrate with salicylic acid and 8-hydroxyquinoline, was characterized with IR, elemental analysis, molar conductance, and thermogravimatric analysis. The standard molar enthalpies of solution of [ SmCl3·6H2O (s) ], [ 2C7H6O3 (s) ], [ C9H7NO ( s ) ] and [ Sm (C7H5O3) 2·( C9H6NO ) ( s ) ] in the calorimetric solvent were determined with the solution-reaction isoperibol calorimeter at 298.15 K to be △sHm^- [ SmCl3·6H2O (s), 298.15 K ] = - 103.98 ± 0.04 kJ·mol^-1, △sHm^- [2 C7H6O3 (s), 298.15 K] = 16.35±0.14 kJ·mol^-1,△sHm^-[C9H7NO (s), 298.15 K] = -6.11±0.08 kJ·mol^-1 and △sHm^-[Sm(C7H5O3)2·(C9H6NO) (s), 298.15 K] = - 130.08 ± 0.04 kJ·mol^-1, respectively. The enthalpy was determined to be △rHm^- = 89.59 ±0.18 kJ·mol^-1 for the reaction SmCl3·6H2O(s) + 2C7H6O3(s) + C9H7NO(s) = Sm (C7H5O3) 2·(C9H6NO) ( s ) + 3HCl (g) + 6H2O ( l ). According to the above results and the data given in literature and through Hess' law, the standard molar enthalpy of formation of Sin( C7H5O3 )2·(C9H7NO)(s) was estimated to be △rHm^- [ Sm (C7H5O3)2·(C9H6NO) (s), 298.15 K] = - 2055.9 ± 3.03 kJ·mol^-1.
基金Fund by the National Natural Science Foundation of China(No.8120119)
文摘Fluorescent mesoporous silica nanoparticles functionalized with carboxyl group(Znq-CMSCOOH) were successfully synthesized by in situ formation route of 8-hydroxyquinolinate zinc complexes in channels of mesoporous silica nanoparticles and post-grafting of carboxyl group on the surface. Moreover,the particle size and structural properties of Znq-CMS-COOH were characterized by transmission electron microscopy(TEM),field emission scanning electron microscopy(FE-SEM),dynamic light scattering(DLS),Fourier transform infrared spectroscopy(FT-IR),UV-vis spectrometer, fluorescence spectrometer and nitrogen adsorption-desorption measurements. The obtained results suggest that the Znq-CMS-COOH presents the uniform spherical shape with the mean diameter of about 85 nm and the obvious wormhole arrangement mesoporous. In addition, the Znq-CMS-COOH possesses green fluorescence with the emission peaks at 495 nm. So the Znq-CMS-COOH, which is beneficial to further modification and tracing, might be a great potential carrier for applying in drug delivery system in the future.
基金Siping Sci-tech Development Planning Project(No.2005012)
文摘The structure of a binuclear cadmium(Ⅱ) quaternary complex, [Cd2(phen)2- Q2(BP)]n 1 (phen = 1,10-phenanthroline, BP = biphenyl-4,4′-dicarboxylic acid, Q = 8-hydroxy- quinoline-anion), has been determined by X-ray crystallography and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. It crystallizes in the monoclinic system, space group P21/n with a = 13.1906(18), b = 10.9623(15), c = 16.947(2)A, β = 111.3430(10)°, V = 2282.5(5)A^3, Z = 4, Mr = 556.85, Dc = 1.620 g/cm^3, F(000) = 1116,μ= 0.994 mm^-1 and S = 1.056. In the structure, 1D chains are connected via biphenyl-4,4′-dicarboxylic acid, 8-hydroxy quinoline anion and binuclear cadmium atoms into an infinite 1-D molecular chain architecture. Via aryl ring π-π stacking interactions a supramolecular structure is formed in 1.
文摘The synergistic extraction of Pr^3+ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester (P507, HL) and 8-Hydroxyquinoline (HQ) in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr^3+ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration oil extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr^3+.
基金supported by the National Natural Science Foundation of China(No:81072338)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (2010)
文摘Chronic exposure to coplanar polychlorinated biphenyls(PCBs),a potent inducer of toxic reactive oxygen species(ROS),in the environment and food can cause liver diseases.It remains unknown whether caffeic acid derivatives(CADs) exerted protective effect on PCB-induced hepatotoxicity.We sought to evaluate the activities of 3CADs on PCB169-induced oxidative stress and DNA damage in the liver.Male ICR mice were administered with1 μmol/mL PCB169 at 5 mL/kg body weight for 2 weeks.The mice were given CADs by gastric gavage for 3weeks.We found that PCB169 decreased the growth rate and reduced the levels of superoxide dismutase(SOD),glutathione(GSH) and GSH peroxidase(GPx).It increased the liver weight,malondialdehyde(MDA)and 8-hydroxy-2'-deoxyguanosine(8-OHdG) levels and CYPlAl activity in the liver tissues and plasma of mice(P〈0.05).Pretreatment of mice with CADs restored the above parameters to normal levels.There was a synergistic protective effect between CADs in preventing MDA and 8-OHdG formation and inducing CYPlAl and phase II metabolism enzyme(SOD,GPx) activities(P〈0.05).In conclusion,PCB169 induced hepatotoxicity and pretreatment with CADs had synergistic protective effects on liver damage.
基金sponsored in part by Science and Technology Commission of Shanghai Municipality, China (No. 07ZR14018)
文摘Pigment epithelium-derived factor (PEDF) is an antiangiogenic factor which is effective in tumour inhibition in a variety of tumours and has not yet been studied in bladder tumour before. In this study the expression of PEDF, interleukin-1α (IL-1α) and -8 (IL-8) in bladder tumours was investigated. Immunohistochemistry was performed on 64 bladder tumour and 23 normal uroepithelium samples. Expression change of the factors was compared with clinicopathological parameters. Correlations between PEDF, IL-1α and IL-8 were analyzed. None of the factors was in relation to gender, tumour occurrence, and size or onset pattern. PEDF (P=0.014) and IL-1α (P=0.049) expression was down-regulated with grade progression. PEDF expression was lower in normal uroepithelium than in papillary urothelial neoplasm of low malignant potential (PUNLMP) (P=0.000) and carcinoma (P=0.009) whilst IL-1α (P=0.000 and P=0.000 respectively) and IL-8 (P=0.000 and P=0.023 respectively) expression was higher in the same grouping. PEDF expression had a negative correlation with IL-8 in PUNLMP (P=0.049, r=-0.578) as well as in tumour grouping (P=0.033, r=-0.276). Deranged expressional change of PEDF, IL-1α and IL-8 could be in relation to loss of differentiation from normal uroepithelium to papillary lesion and eventually to carcinoma.
基金the National Natural Science Foundation of China(Grant No.10974074)
文摘Stable and persistent bipolar resistive switching was observed in an organic diode with the structure of indium-tin oxide (ITO)/bis(8-hydroxyquinoline) cadmium (Cdq2)/Al. Aggregate formation and electric field driven trapping and detrapping of charge carriers in the aggregate states that lie in the energy gap of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the organic molecule were proposed as the mechanism of the observed bipolar resistive switching, and this was solidly supported by the results of AFM investigations. Repeatedly set, read, and reset measurements demonstrated that the device is potentially applicable in non-volatile memories.
基金supported by the National Natural Science Foundation of China(No.21162015)Science Foundation of State Key Laboratory of Structural Chemistry(No.20100009)
文摘8-Hydroxyquinoline salt of pyrazine-2,3,5,6-tetracarboxylic acid [HQ]2[H2pztc]· 2H2O (1) was prepared and characterized by single-crystal X-ray diffraction, NMR, IR, TGA, elemental analysis and fluorescent measurements. Compound 1 crystallizes in orthorhombic, space group Pbcn with a = 9.953(3), b = 15.966(3), c = 16.081(5) A, V = 2555.5(13) A3, Z = 4, μ = 0.122 mm^-1, Dc = 1.514 Mg/m3, T= 296(2) K, C26H22N4O12, Mr = 582.48, F(000) = 1208, S = 1.006, R = 0.0448 and wR = 0.1149. Compound 1 has a three-dimensional (3D) network, in which pyra- zine-2,3,5,6-tetracarboxylic acids build up two-dimensional (2D) sheets and 8-hydroxyquinoline cations and water molecules act as pillars to connect the 2D sheets into an extended 3D network through strong intermolecular hydrogen bonding and π…π stacking interactions. Especially, a very short O-H…O hydrogen bond (O…O 2.470(2) A) between two neighboring [H2pztc] anions was observed.
文摘2,7′-(Ethylene)-bis-8-hydroxyquinoline was optimized with DFT/B3LYP and ab initio HF methods, so ion- ization potential and electron affinity could be determined. Absorption spectrum was calculated by ZINDO and TD-DFT. CIS method was used to calculate the S1 excited states of the compound and afterwards the emission spectrum was computed. When the solvent effect was taken into account, the computed results show encouraging agreement with known experimental data. The results of analyzing the relationship between the energies and absorption spectra indicate that the ability to transporting electrons is strengthened compared with 8-hydroxyquinoline and that absorption and emission spectra are red-shifted. The intramoleeular reor- ganization energy of tris(2,7′-(ethylene)-bis-8-hydroxyquinoline)-aluminum implies its electron transporting property is worse than tris(8-hydroxyquinoline)-aluminum. The predicted maximum emission wavelength is red-shifted compared with tris(8-hydroxyquinoline)-aluminum.
基金Sponsored bythe National Natural Science Foundation of China (20331010 , 20201007 and 90406002) Specialized Research Fund for theDoctoral Programof Higher Education (20030007014)
文摘The single crystal of bi(8-hydroxyquinoline) bihydrated cobalt (Ⅱ) complex, [ Co(Q)2 (H2O2 ] (Q = 8-hydroxyquinoline ion), has been synthesized by general method and structurally characterized by single crystal X-ray diffraction. Crystal data: C18H16CoN2O4, monoclinic, C2/c, α = 1.336 2(4) nm, b = 0.941 2(3) nm, c = 1.354 3(4) nm, β= 109.672(4)°, Z = 4. In the complex, Co( Ⅱ ) ion is six-coordinated, forming a distorted octahedron. H-bonding and π-π stacking interaction play a significant role to form and stabilize the three-dimensional structure.