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1.
研究了无溶剂条件下纳米Cu2O催化二苯甲烷二氨基甲酸苯酯(MDPC)热分解制备二苯甲烷二异氰酸酯(MDI),考察了纳米Cu2O的制备条件与反应条件对MDPC热分解反应性能的影响.结果表明,水解法制备的纳米Cu2O在Ar中于300℃焙烧2h,其催化性能最佳;最佳的反应条件为Cu2O用量为原料总重的0.06%,反应温度220℃,反应压力0.6kPa,反应时间12min,此时MDPC转化率达到99.8%,MDI选择性86.2%.  相似文献   

2.
Development of new treatment strategies and chemotherapeutic agents is urgently needed to combat the growing multidrug resistant species of Candida. In this direction, a new series of Cu (II), Co (II), Ni (II) and Zn (II) heteroleptic complexes were synthesized, characterized and evaluated for antifungal activity. Based on spectral characterization and physical measurements, an octahedral geometry was assigned to [Co(L1)(L2)ClH2O] ( C2 ), [Ni(L1)(L2)ClH2O] ( C3 ), [Zn(L1)(L2)ClH2O] ( C4 ) complexes, while a distorted octahedral geometry was assigned to [Cu(L1)(L2)ClH2O] ( C1 ) complex. All the synthesized compounds were tested for antifungal activity against 11 Candida albicans isolates, including fluconazole (FLC)‐resistant isolates, by determining minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC), following CLSI guidelines. The mechanism of their antifungal activity was assessed by studying their effect on the plasma membrane using flow cytometry and quantifying the ergosterol contents. All the test compounds showed varying levels of antifungal activity. Both the ligands showed moderate antifungal activity with a median MIC value of 100 μg/mL with no fungicidal activity. Compound C3 was the most potent compound with median MIC and MFC values of 0.10 and 1.60 μg/mL, respectively. Flow cytometry analysis revealed that these compounds at MFC values disrupt the cell membrane, resulting in propidium iodide entering the cells. These compounds also reduced a considerable amount of ergosterol content after treating the cells with MIC and sub‐MIC values. This study indicates that these compounds have high antifungal activity against C. albicans, and have the potential to be developed as novel antifungal drugs.  相似文献   

3.
Cu2O nanoparticles (nano-Cu2O) modified glassy carbon electrode (GCE) was fabricated and used to investigate the electrochemical behaviour of 4-nitrophenol (4-NP) by cyclic voltammetry (CV), chronoamperometry (CA), chronocoulometry (CC) and differential pulse voltammetry (DPV). Compared with GCE, a remarkable increase in oxidation peak current was observed. It indicates that nano-Cu2O exhibits remarkable enhancement effect on the electrochemical oxidation of 4-NP. Under the optimised experimental conditions, the oxidation peak currents were propotional to 4-NP concentration in the range from 1.0?×?10?6 to 4.0?×?10?4?mol?L?1 with a detection limit of 5.0?×?10?7?mol?L?1 (S/N?=?3). The fabricated electrode presented good repeatability, stability and anti-interference. Finally, the proposed method was applied to determine 4-NP in water samples. The recoveries for these samples were from 94.60% to 105.5%.  相似文献   

4.
It has previously been demonstrated that baculovirus infection of the Spodoptera frugiperda Sf-9 (Sf-9) and Trichoplusia ni BTI-Tn-5B1-4 (Tn-5B1-4) insect cell lines leads to oxidative stress as measured by protein and membrane lipid oxidation and that this oxidative damage contributes to cell death. As a result of these findings, it was hypothesized that baculovirus infection stimulates superoxide radical (O 2 ·— synthesis in the mitochondria and that the resulting O 2 ·— accumulation overwhelms the cells’ antioxidant defenses. We investigated the ability of manganese superoxide dismutase (MnSOD) expression (which reduces O 2 ·— to H2O2) to overcome the oxidative damage caused by baculovirus infection. It was found that MnSOD expression significantly reduced oxidative damage in baculovirus-infected Tn-5B1-4 cells but had no significant effect on oxidative damage in baculovirus-infected Sf-9 cells. The results are consistent with the hypothesis that O 2 ·— accumulation in the mitochondria is at least partially responsible for the oxidative damage resulting from the baculovirus infection of insect cells.  相似文献   

5.
S,S,S-Tris(2-ethylhexyl) phosphorotrithioate proved to be an effective solvent mediator for constructing a mexiletine-sensitive membrane electrode in combination with an ion-exchanger, sodium tetrakis[3,5-bis(2-methoxyhexafluoro-2-propyl)phenyl]borate. Among a series of phosphorus compounds containing phosphoryl (P=O) groups, this solvent mediator showed the highest sensitivity to mexiletine in phosphate-buffered physiological saline containing 0.15 mol L−1 NaCl and 0.01 mol L−1 NaH2PO4/Na2HPO4 (pH 7.4), giving a detection limit of 2 × 10−6 mol L−1 with a slope of 58.8 mV decade−1. This is the best reported detection limit of any mexiletine-sensitive electrode developed to date. Owing to its high selectivity toward inorganic cations, the electrode was used to determine the level of mexiletine in saliva, the monitoring of which is quite effective for controlling the dose of this drug noninvasively. The mexiletine concentrations determined with the mexiletine-sensitive electrode compared favorably with those determined by high-performance liquid chromatography.  相似文献   

6.
The heat effects arising at heating of Spirulina platensis cell culture containing different quantity of water (from 98.2 to 10.5 mass% H2O) have been studied. The hydration of Sp. pl. cells determined by the method of microcalorimetry at 25°C (Δn) was equal to 0.32±0.02 g H2O/g of dry biomass. The heat (–Q) evolved by cells in the temperature range 5–52°C decreased exponentially at decrease of mass% H2O and reached zero value at 30.5±3.0 mass% H2O. The total heat of cell denaturation did not change in the range 98.2–40.5 mass% H2O and it sharply dropped at lower values of water.  相似文献   

7.
New complexes CuL2×2H2O, CoL2×3H2O, MnL2×2H2O and FeL3×2H2O, L=γ-L -glutamyl-5-(p-nitroanilide), were synthesized and characterized by their spectral, magnetic and thermal properties. The thermal stabilities of the synthesized complexes were examined in the temperature range 20–500°C. In all these complexes γ-L -glutamyl-5-(p -nitroanilide) acts as a bidentate ligand, its coordination involving the carbonyl oxygen and the nitrogen atom of the second amino group. The local structure around the Cu(II) ion is pseudotetrahedral. In the Co(II), Mn(II) and Fe(III) complexes, the metal ions are in the high-spin form, with octahedral stereochemistry. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

8.
四氯合铂酸钾分别与邻、间、对磺基苯甲酸在乙腈和水中利用水热合成获得了3个铂的N-(1-亚氨基乙基)乙脒配合物:[Pt(NIA)_2]·(2-sb)·2H_2O(1),[Pt(NIA)_2]·(3-sb)·3H_2O(2)和[Pt(NIA)_2]·(1,4-dsb)·2H_2O(3)(NIA=N-(1-亚氨基乙基)乙脒,2-sb~2-=2-磺基苯甲酸二价阴离子、3-sb~2-=3-磺基苯甲酸二价阴离子、1,4-dsb~2-=1,4-二磺基苯二价阴离子)。合成过程中发生了乙氰三聚以及4-sb~2-转变为1,4-dsb~2-的反应。对配合物进行了元素分析、红外、紫外、荧光、热重和粉末X射线衍射表征,并利用单晶X射线衍射测定了配合物的晶体结构。3个配合物为阳离子-阴离子物种,阳离子为[Pt(NIA)_2]~(2+),中心金属离子四配位平面构型;阴离子与阳离子、水形成氢键,组成一个三维网络结构,但3个配合物的氢键模式不同。配合物在热稳定性、荧光性质上有一定差异。  相似文献   

9.
The aqueous reaction of barium carbonate with 2-nitrobenzoic acid (2-nbaH) results in the formation of a one-dimensional coordination polymer, catena-poly[[hexa(aqua)dibarium(II)]bis[(μ 2-2-nitrobenzoate-O,O,O-NO2)(μ 2-2-nitrobenzoate-O,O,O′)]] 1. On heating at 100°C compound 1 is dehydrated to anhydrous barium bis(2-nitrobenzoate) 2. The anhydrous compound can be re-hydrated to 1 on exposure to water vapour. Compounds 1 and 2 were characterized by elemental analysis, IR and UV-Vis spectra, DSC thermograms, weight loss studies and the structure of 1 was determined. 1 and 2 can be thermally decomposed to BaCO3 by heating at 800°C. The polymer [[Ba(H2O)3]2(μ 2-2-nba-O,O,O-NO2)2 (μ 2-2-nba-O,O,O′)2] n 1 crystallizes in the centrosymmetric triclinic space group Pī and all atoms are located in general positions. The polymeric structure is based on a dimeric unit and consists of three water molecules coordinated to a central Ba(II) and two unique 2-nitrobenzoate (2-nba) anions, one of which (μ 2-2-nba-O,O,O-NO2) functions as a tridentate ligand and is linked to a Ba(II) through the oxygen atom of the-NO2 group and forms a monoatomic μ 2-carboxylate bridge between two symmetry related Ba(II) ions with a Ba···Ba distance of 4·5726(14) ?. The second unique 2-nba anion (μ 2-2-nba-O,O,O′) also functions as a tridentate ligand with the carboxylate oxygen atoms linked to a Ba(II) ion in a bidentate fashion and one of the carboxylate oxygen atoms forming a monoatomic bridge between two symmetry related Ba(II) ions resulting in a Ba···Ba separation of 4·5406(15) ?. These differing tridentate 2-nba ligands link {Ba(H2O)3} units into a one-dimensional polymeric chain extending along b axis. In the infinite chain each nine coordinated Ba(II) is bonded to three water molecules and further linked to six oxygen atoms of four different 2-nitrobenzoate anions with alternating pairs of Ba(II) ions in the chain bridged by a pair of (μ 2-2-nba-O,O,O-NO2) and (μ 2-2-nba-O,O,O′) ligands resulting in alternating Ba···Ba distances of 4·5406(15) and 4·5726(14) ? across the chain. Dedicated to Prof. S. K. Paknikar on the occasion of his 73rd birthday.  相似文献   

10.
An efficient and novel synthesis of 2,3-disubstituted 2,3-dihydroquinazolin-4(1H)-ones via one-pot, three-component reaction of isatoic anhydride, primary amines and aromatic aldehydes catalyzed by Bi(NO3)3·5H2O under solvent-free conditions is described. Oxidation of these 2,3-dihydroquinazolin-4(1H)-ones to their quinazolin-4(3H)-ones was also successfully performed in the presence of Bi(NO3)3·5H2O. This new method has the advantages of convenient manipulation, short reaction times, excellent yields, very easy work-up, and the use of commercially available, low cost and relatively non-toxic catalyst. The role of Bi(NO3)3·5H2O was also investigated in these transformations.  相似文献   

11.
The copper(II) complex [Cu(p-Tdp)(H2O)2]·2H2O, where p-Tdp is the anion of p-toluidine-N,N-di-3-propionic acid (or N,N-di(2-carboxyethyl)-p-toluidine), has been synthesized and characterized by X-ray diffraction. Three crystallographically independent [Cu(p-Tdp)(H2O)2] molecules have a similar structure. The Cu atoms have a square pyramidal environment (4+1) with a small trigonal bipyramidal distortion. The ortho-H atom of the benzene ring blocks up the sixth coordination position of the Cu polyhedron. The basal plane is formed by the donor atoms of the tridentate ligand and by the water molecule (average bond length Cu---N 2.03, Cu---O 1.93, Cu---Ow 2.00 Å), the apex is occupied by another water molecule (Cu---Ow 2.27 Å). The Cu atoms are located 0.20–0.30 Å out of the mean planes of the four basal atoms towards the apical Ow atom. The IR and electronic absorption spectra of p-Tdp and the title compound have been described. UV–Vis reflectance spectra shows that the complex has the same square pyramidal geometry in the crystal state and in solution. The protonation constants of the ligand log K1=6.87(2), log K2=3.75(2), log K3=2.57(2) and stability constants log KCuH(p-Tdp)=2.13(5), log KCu(p-Tdp)=6.38(3) were determined by pH-titration at 25.0 °C and I=0.1 M KNO3.  相似文献   

12.
The reaction of m-aminophenol with CH2O and H2S (1: 2: 1 ratio) afforded 2, 12-dioxa-4, 14-dithia-6, 16-diazatricyclo[15.3.1.17,11]docosa-1(20), 7(22), 8, 10, 17(21), 18-hexaene in ∼9% yield. Aminophenol o-and p-isomers react with CH2O and H2S (1: 3: 2) to form 2-and 4-[4H-1,3,5-dithiazin-5(6H)-yl]phenols in 86 and 71% yields, respectively. In the crystal structure of the latter, molecules contain dithiazine cycles in the chair conformation with the axial hydroxyphenyl group. Molecular packing represents a combination of molecules forming chains due to the OH...S intermolecular hydrogen bond. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 305–308, February, 2006.  相似文献   

13.
Optimal design and operation of bioreactors for insect cell culture is facilitated by functional relations providing quantitative information on cellular metabolite consumption kinetics, as well as on the specific cell growth rates (μG). Initial specific consumption rates of glucose, malate, and oxygen, and associated changes in μG, were measured forSpodoptera frugiperda clone 9 (Sf9) cells grown in batch suspension culture in medium containing 7–35 mM glucose, 0–16 mM malate, and 4–16 mM glutamine. The initial specific glucose consumption rate (q G ) could be described by a modified Michaelis-Menten equation treating malate as a “competitive” inhibitorK 1 = 6.5 mM) and glutamine as a “noncompetitive” inhibitorK I = 14 mM) ofq G , with aK m of 7.1 mM for glucose. All three carbon sources were found to increase μG in a saturable manner, and a modified Monod equation was employed to describe this relationship (μGmax = 0.047 h-1). The initial specific oxygen consumption rate (qO2) in Sf9 cells could be related to μG by the maintenance energy model, and it was calculated that, under typical culture conditions, about 15–20% of the cellular energy demand comes from functions not related to growth. Fitted parameters in mathematical expression for μg: K4, Monod constant for glucose (mM); K5, modified Monod constant for malate (mM); K6, Monod constant for glutamine (mM); mo2, specific consumption rate of oxygen by the cells under zero-growth conditions (nmol/cell/h); qF, initial specific fumarate production rate (nmol/cell/ h);q G , initial specific glucose consumption rate (nmol/cell/h); qGmax, maximum initial specific glucose consumption rate (nmol/cell/h);q M , initial specific malate consumption rate (nmol/cell/h); qo2, initial specific oxygen consumption rate (nmol/cell/h); Yo2, cell yield on oxygen (cells/nmol); μ, initial specific cell growth rate (h-1); μg, initial specific cell growth rate (h-1); μGmax, maximum initial specific cell growth rate (h-1).  相似文献   

14.
The hydrothermal reaction of In3+ and 1,2,4-benzenetricarboxylic acid with the presence of piperazine leads to the generation of a novel 3D porous coordination polymer, [H3O][In2(btc)(bdc)(OH)2]·5.5H2O (1), (btc=1,2,4-benzenetricarboxylate, bdc=1,4-benzenedicarboxylate). Compound 1 crystallizes in orthorhombic space group Pbca with a=16.216(7) Å, b=13.437(6) Å, c=31.277(14) Å, and Z=8. It is interesting to find that the in-situ decarboxylation reaction of 1,2,4-benzenetricarboxylate (btc) partially transformed into 1,4-benzenedicarboxylate (bdc) occurs. The 16 indium(III) centers were linked by four btc, four bdc and two μ2-OH ligands to form a box-girder. The adjacent box-girders are further connected by the bdc and btc ligands to generate a novel porous metal–organic framework containing nanotubular open channel with a cross-section of approximately 11.5×11.3 Å2. The micropores are occupied by lattice water molecules, and the solvent-accessible volume of the unit cell was estimated to be 3658.6 Å3, which is approximately 53.7% of the unit-cell volume (6815.4 Å3).  相似文献   

15.
合成和表征了5个螺旋配位聚合物{[Cu(Hbpma)(H2O)4]2(SO4)3·3.5H2O}n (1)、{[Ni(Hbpma)(H2O)4]4(SO4)6·10.75H2O}n (2)、{[Mn(Hbpma)(H2O)4](SO4)1.5·3H2O}n (3)、{[Zn(Hbpma)(H2O)4]4(SO4)6·4H2O·4CH3OH}n (4)和{[Cu(Hbpma)2(H2O)2](SO4)2·9H2O}n (5), 其中bpma代表N,N'-双(3-吡啶甲基)胺。晶体结构分析表明配合物1~4为一维链状结构, 配合物5为二维层状结构, 其中金属离子由质子化的bpma配体桥连。值得注意的是, 采取反-反式构象的柔性bpma配体使得配合物12为假螺旋链结构, 配合物34为螺旋链结构, 配合物5为螺旋层结构。同时研究了配合物的磁性和热稳定性。  相似文献   

16.
The article describes the synthesis and single-crystal X-ray analysis of two sulfato and one thiocyanato copper(II) complex with 2-acetylpyridine S-methylisothiosemicarbazone (HL) of the formulae [Cu(HL)SO4(H2O)]·H2O (1), [Cu2(HL)2(μ-SO4)2]·2H2O (2) and [Cu(HL)(NCS)(SCN)] (3), as well as the structure of the protonated ligand H2L+I. Complexes 1 and 2 were obtained from the reaction of aqueous/methanolic CuSO4·5H2O and ethanolic/methanolic H2L+I solutions, respectively. Complex 3 was synthesized by the reaction of methanolic solutions of Cu(ClO4)2·6H2O, the ligand and NH4SCN, with the addition of triethyl orthoformate. All three complexes have a slightly deformed square-pyramidal structure (τav = 0.15) with the tridentate NNN neutral ligand in the basal plane. In complexes 1 and 3 the apical position is occupied by the oxygen atom of the monodentate SO4 group, or the sulfur atom of the SCN group. Thanks to the hydrogen bonds, complex 3 may be thought of as having a pseudo-dimeric structure. In the authentic centrosymmetric dimer 2, the oxygen atoms of both SO4 groups occupy also the apical position of both coordination polyhedra, as well as an equatorial position. Complexes 1 and 3 have μeff values characteristic of magnetically isolated mononuclear Cu(II) complexes. In contrast to them, complex 2 has a μeff value of 1.57 BM, which is in agreement with its dinuclear structure. All the complexes, in addition to the X-ray analysis and magnetic measurements, were characterized by IR and UV–Vis spectroscopy and by thermal analysis.  相似文献   

17.
四氯合铂酸钾分别与邻、间、对磺基苯甲酸在乙腈和水中利用水热合成获得了3个铂的N-(1-亚氨基乙基)乙脒配合物:[Pt(NIA)2]·(2-sb)·2H2O(1),[Pt(NIA)2]·(3-sb)·3H2O(2)和[Pt(NIA)2]·(1,4-dsb)·2H2O(3)(NIA=N-(1-亚氨基乙基)乙脒,2-sb2-=2-磺基苯甲酸二价阴离子、3-sb2-=3-磺基苯甲酸二价阴离子、1,4-dsb2-=1,4-二磺基苯二价阴离子)。合成过程中发生了乙氰三聚以及4-sb2-转变为1,4-dsb2-的反应。对配合物进行了元素分析、红外、紫外、荧光、热重和粉末X射线衍射表征,并利用单晶X射线衍射测定了配合物的晶体结构。3个配合物为阳离子-阴离子物种,阳离子为[Pt(NIA)2]2+,中心金属离子四配位平面构型;阴离子与阳离子、水形成氢键,组成一个三维网络结构,但3个配合物的氢键模式不同。配合物在热稳定性、荧光性质上有一定差异。  相似文献   

18.
Reaction of mer-[RuCl3(DMSO–S)2(DMSO–O] (1) with pyridine (py) in dichloromethane yields mer-[RuCl3(DMSO–S)(DMSO–O)(py)] (2). A single crystal suitable for X-ray diffraction was obtained by recrystalization with dichloromethane and diethyl ether. X-ray diffraction analysis revealed an unusual case in which two independent molecules (2a and 2b) are present in the asymmetric unit cell. Both molecules have distorted octahedral geometry in which DMSO is bound through oxygen and sulfur. Density functional theory (DFT) calculations were performed for 2a and 2b in gas phase to investigate bonding shown by the two DMSO ligands. Optimizations were done on both DMSO ligands bonded through S, both DMSO ligands bonded through O, one DMSO bonded through O, and the other through S but opposite to the actual molecule. The energy differences of the optimized structures were calculated.  相似文献   

19.
Dynamic changes in reactive oxygen species (ROS) of Taxus cuspidata cells immobilized on polyurethane foam were investigated and the relation between ROS content and taxol production was discussed. Immobilization shortened the lag period of cell growth and moderately increased H2O2 and O2 −• contents inside the microenvironment within the first 15 d. After 20 d, excessive production of H2O2 and O2 −• was observed accompanied by marked increases in membrane lipid peroxidation and cell membrane permeability. The taxol content of immobilized cells was fourfold that of suspended cells at d 35. The addition of exogenous H2O2 barely affected malondialdehyde content and cell membrane permeability but led to an obvious accumulation of taxol. It is inferred that the intracellular and extracellular H2O2 inside the microenvironment might be one factor promoting taxol biosynthesis under the immobilization stress.  相似文献   

20.
Eu2(BPOPB)3H2O, an europium complex chelated with bis(β-diketone), was synthesized. Its properties have been investigated by absorption spectrum, emission spectrum and luminescence lifetime measurement. The complex displays strong red luminescence upon irradiation at the ligand band around 355 nm, which indicates that the bis-β-diketonate ligand BPOPB is an efficient sensitizer. The Judd–Ofelt parameters obtained from the emission spectrum of Eu2(BPOPB)3H2O have been used to calculate the total spontaneous emission probabilities (A), the radiative lifetime (τrad), the fluorescence branching ratio (β) and the stimulated emission cross-sections (σ). The luminescence lifetimes are determined to be 402 and 169 μs for Eu2(BPOPB)3H2O and Eu(DBM)3(H2O)2, respectively. The relationship between the structures of rare-earth complexes and luminescence lifetimes was analyzed. The radiative properties reveal that Eu2(BPOPB)3H2O is potential to be an efficient luminescent material.  相似文献   

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