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1.
The efficiency of differently prepared TiO2 particles in photochemical water splitting through band gap irradiation of aqueous suspensions has been investigated. The effect of pH and loading with noble metals and RuO2 has been examined. Particular attention has been devoted to dioxygen evolution and photoadsorption. 相似文献
2.
Glucose biosensor based on the room-temperature phosphorescence of TiO2/SiO2 nanocomposite 总被引:1,自引:0,他引:1
The direct immobilization of glucose oxidase (GOD) on TiO2/SiO2 nanocomposite and its application as glucose biosensor were investigated. The room-temperature phosphorescence of TiO2/SiO2 nanocomposite can be quenched by hydrogen peroxide (H2O2). The detection of glucose may be accomplished by monitoring the formation of hydrogen peroxide which generated in the oxidation process of glucose with the catalysis of GOD. To our surprise, by using a 96-hole polyporous plate accessory of fluorescence spectrophotometer, the biosensor exhibits excellent linear response to glucose concentrations ranging from 1.0 × 10−9 to 1.0 × 10−2 M with a detection limit of 1.2 × 10−10 M. The TiO2/SiO2 nanocomposite can be used as both supporting material and signal transducer. The phosphorescence intensity and color of the biosensor change obviously and even could be observed with naked eyes by continuous addition of glucose. Based on the room-temperature phosphorescence of TiO2/SiO2 nanocomposite, a new method of solid substrate-room-temperature phosphorimetry (SS-RTP) for glucose determination is proposed. A glucose biosensor was fabricated with wide determination concentration range, low detection limit, high sensitivity, and fast response time. And the biosensor has been successfully applied to the determination of glucose in human blood serum. The coacervation of GOD enzyme and its interaction with TiO2/SiO2 nanocomposite enlarge the surface area and enhance the chemical stability of GOD. The nice biocompatibility, large surface area, good chemical stability and nontoxicity of the TiO2/SiO2 nanocomposite have made this material suitable for functioning as biosensor. 相似文献
3.
Recent updates on Magnetic Nano-Particles (MNPs) based separation of nucleic acids have received more attention due to their easy manipulation, simplicity, ease of automation and cost-effectiveness. It has been indicated that DNA molecules absorb on solid surfaces via hydrogen-bonding, and hydrophobic and electrostatic interactions. These properties highly depend on the surface condition of the solid support. Therefore, surface modification of MNPs may enhance their functionality and specification. In the present study, we functionalized Fe3O4 nano-particle surface utilizing SiO2 and TiO2 layer as Fe3O4/SiO2 and Fe3O4/SiO2/TiO2 and then compare their functionality in the adsorption of plasmid DNA molecules with the naked Fe3O4 nano-particles. The result obtained showed that the purity and amount of DNA extracted by Fe3O4 coated by SiO2 or SiO2/TiO2 were higher than the naked Fe3O4 nano-particles. Furthermore, we obtained pH 8 and 1.5 M NaCl as an optimal condition for desorption of DNA from MNPs. The result further showed that, 0.2 mg nano-particle and 10 min at 55 °C are the optimal conditions for DNA desorption from nano-particles. In conclusion, we recommended Fe3O4/SiO2/TiO2 as a new MNP for separation of DNA molecules from biological sources. 相似文献
4.
近年来,二氧化钛纳米颗粒(TiO2NPs)环境释放量不断增加,并通过多种途径进入湿地生态系统,不可避免地影响到湿地生态系统环境和功能。然而,关于TiO2NPs对沼泽土壤反硝化作用和氧化亚氮(N2O)排放的影响机及制尚不明确。选择典型沼泽土壤,通过室内培养实验研究土壤理化性质、反硝化酶活性、反硝化速率(DNR)和N2O排放对不同剂量TiO2NPs 0 mg/kg (CK)、10 mg/kg (A10)、100 mg/kg (A100)、1000 mg/kg (A1000)输入的响应,探讨TiO2NPs输入对沼泽土壤反硝化作用和N2O排放影响的内在机制。结果表明:不同剂量TiO2NPs处理显著降低了土壤pH (P<0.05),A10处理显著降低土壤总有机碳(TOC)含量(P<0.01),A1000处理显著降低硝态氮(NO3--N)和亚硝态氮(NO2--N)含量(P<0.05)。TiO2NPs处理抑制硝酸盐还原酶(NAR)活性,促进一氧化氮还原酶(NOR)和氧化亚氮还原酶(NOS)活性(P<0.01),A1000处理先促进后抑制了亚硝酸盐还原酶(NIR)活性(P<0.05)。不同剂量TiO2NPs处理抑制了土壤DNR,促进了N2O排放,TiO2NPs处理通过抑制NIR活性,降低土壤DNR,同时通过促进NOR活性,提高N2O排放。综上,TiO2NPs输入通过影响反硝化还原酶活性改变沼泽土壤反硝化过程,导致沼泽土壤N2O排放增加,改变湿地氮的源、汇功能,影响全球气候变化。为TiO2NPs输入的湿地环境风险评估研究提供理论基础。 相似文献
5.
The title compounds were made by reacting bis(diphenylphosphino)methane (dppm) with reduced solutions of OsCl64? and Ru2OCl104?. The crystal and molecular structures of these compounds have been determined form three-dimensional X-ray study. The cis-isomers crystallize with one CHCl3 per molecule of the complex. All three compounds crystallize in the monoclinic space group P21/n with unit cell dimensions as follows: Cis-OsCl2(dppm)2·CHCl3: a = 13.415(4) Å, b = 22.859(4) Å, c = 16.693(3) Å, β = 105.77(3)°, V = 4926(3) Å3, Z = 4. cis-RuCl2(dppm)2·CHCl3: a = 13.442(3) Å, b = 22.833(7) Å, c = 16.750(4) Å, β = 105.53(2)°, V = 4953(3) Å3, Z = 4. trans-RuCl2(dppm)2: a = 11.368(7) Å, b = 10.656(6) Å, c = 18.832(12) Å; β = 103.90(6)°, V = 2213(7) Å3; Z = 2. The structures were refined to R = 0.044 (Rw = 0.055) for cis-OsCl2(dppm)2·CHCl3; R = 0.065 (Rw = 0.079) for cis-RuCl2(dppm)2·CHCl3 and R = 0.028 (Rw = 0.038) for trans-RuCl2(dppm)2. The complexes are six coordinate with stable four-membered chelate rings. The PMP angle in the chelate rings is ca. 71° in each case. 相似文献
6.
城市森林在吸收、滞留大气污染物,改善城市生态环境方面具有重要意义。以大庆市6种常见绿化树种为研究对象,采用水洗-滤膜法和熏气试验探究不同树种对总悬浮颗粒物(TSP)、大颗粒物(PM>10)、粗颗粒物(PM3—10)和细颗粒物(PM1—3)的滞留规律以及对大气中SO2、NO2的消减效果。研究结果表明:(1)不同树种的滞尘能力差异显著(P<0.05),对TSP的滞留量从大到小依次为:油松(3.82±0.40)g/m2>红瑞木(1.45±0.12)g/m2>紫丁香(1.22±0.17)g/m2>梣叶槭(1.21±0.13)g/m2>大叶杨(0.93±0.17)g/m2>旱柳(0.54±0.14)g/m2;(2)树种间对不同颗粒物的滞留量具有显著差异(P<0.05),供试树种对不同粒径颗粒物滞留的质量占比表现... 相似文献
7.
Ge Wang 《Inorganica chimica acta》2005,358(4):933-940
Adding one equivalent of H2O2 to compounds of stoichiometry MoCl2(O)2(OPR3)2, OPR3 = OPMePh2 or OPPh3, leads to the formation of oxo-peroxo compounds MoCl2(O)(O2)(OPR3)2. The compound MoCl2(O)(O2)(OPMePh2)2 crystallized with an unequal disorder, 63%:37%, between the oxo and peroxo ligands, as verified by single-crystal X-ray diffractometry, and can be isolated in reasonable yields. MoCl2(O)(O2)(OPPh3)2, was not isolated in pure form, co-crystallized with MoCl2(O)2(OPPh3)2 in two ratios, 18%:82% and 12%:88%, respectively, and did not contain any disorder in the arrangement of the oxo and peroxo groups. These complexes accomplish the isomerization of various allylic alcohols. A mechanism of this reaction has been constructed based on 18O isotopic studies and involves exchange between the alcohol and metal bonded O atoms. 相似文献
8.
Alfred Moor Paul S. Pregosin Luigi M. Venanzi Alan J. Welch 《Inorganica chimica acta》1984,85(1):103-110
Several clusters complexes of composition [Pt4(μ2-CO)5L4] have been synthesized and characterized, using 31P and 195Pt NMR. L = PEt3, PMe2Ph, PMePh2, PEt2But. The molecular structure of a new monoclinic modification of the PMe2Ph derivative has been determined: space group P21/n with a = 19.698(4), b = 10.9440(20), and c = 21.360(6) Å, β = 112.432(18)°, Z = 4. Using 4751 reflections measured at 290 ± 1 K on a four-circle diffractometer the structure has been refined to R = 0.0846. The molecule has no imposed symmetry, but the central Pt4(CO)5P4 core has the approximate C2v architecture established for the previously known orthorhombic modification. The Pt4 unit is thus a highly distorted, edge-opened (3.3347 Å) tetrahedron, with five edge-bridging carbonyl and four terminal phosphine ligands. In contrast to the crystallographic results 31P and 195Pt NMR spectra reveal equivalent 31P and 195Pt spins, which can be interpreted in terms of a tetrahedral arrangement of platinum atoms. It is suggested that this equivalence arises from time-averaging of all possible isomeric edge-opened tetrahedra. 相似文献
9.
A new CoII/CoIII hexanuclear complex, [Co4IICo2III(dea)2(Hdea)4)(piv)4](ClO4)2·H2O 1, has been obtained by reacting cobalt(II) perchlorate, diethanolamine, and pivalic acid (H2dea = diethanolamine and piv = pivalato anion). The cobalt ions are held together by four μ3 and four μ2 alkoxo bridges as well as by four syn-syn carboxylato groups. The hexanuclear motif contains four Co(II) and two Co(III) ions. The {CoII4CoIII2(μ2-O)4(μ3-O)4} core can be described as a four face-sharing monovacant and bivacant distorted heterocubane units. The cobalt(III) ions are hexacoordinated. Two of the cobalt(II) are hexacoordinated, while the two others are pentacoordinated with a bipyramidal stereochemistry. The magnetic properties of 1 have been investigated in the temperature range 1.9-300 K. Compound 1 exhibits an overall antiferromagnetic behaviour with a ground singlet spin state. 相似文献
10.
Domonique O. Downing 《Inorganica chimica acta》2011,375(1):329-332
The rhodium dimer [Rh2H(PPh2)2(PPh3)3]− was prepared from RhCl(PPh3)3 and K4Sn9 in the presence of 2,2,2-cryptand in ethylenediamine/toluene solvent mixtures. The [K(2,2,2-crypt)]+ salt was isolated and characterized via NMR and X-ray diffraction studies. The solid state structure reveals a binuclear, diphenylphosphido-bridged, 32 electron Rh(I)-Rh(I) complex with edge-shared tetrahedral and square planar Rh centers with overall Cs point symmetry. 1-D and 2-D 1H, 31P, and 31P{1H} NMR experiments were used to characterize the complex. 相似文献
11.
Complexes of the type [Pt(amine)4]I2 were synthesized and characterized mainly by multinuclear (195Pt, 1H and 13C) magnetic resonance spectroscopy. The compounds were prepared with different primary amines, but not with bulky amines, due to steric hindrance. In 195Pt NMR, the signals were observed between −2715 and −2769 ppm in D2O. The coupling constant 3J(195Pt-1H) for the MeNH2 complex is 42 Hz. In 13C NMR, the average values of the coupling constants 2J(195Pt-13C) and 3J(195Pt-13C) are 18 and 30 Hz, respectively. The crystal structure of [Pt(EtNH2)4]I2 was determined by X-ray diffraction methods. The Pt atom is located on an inversion center. The structure is stabilized by H-bonding between the amines and the iodide ions. The compound with n-BuNH2 was found by crystallographic methods to be [Pt(n-BuNH2)4]2I3(n-BuNHCOO). The crystal contains two independent [Pt(CH3NH2)4]2+ cations, three iodide ions and a carbamate ion formed from the reaction of butylamine with CO2 from the air. When the compound [Pt(CH3NH2)4]I2 was dissolved in acetone, crystals identified as trans-[Pt(CH3NH2)2(H3CNC(CH3)2)2]I2 were isolated and characterized by crystallographic methods. Two trans bonded MeNH2 ligands had reacted with acetone to produce the two N-bonded Schiff base Pt(II) compound. 相似文献
12.
Pavel A. Abramov Rita Hernandez-Molina Alexander V. Virovets Pedro Gili Vladimir P. Fedin 《Inorganica chimica acta》2010,363(13):3330-3337
Reaction of [Mo2O2(μ-S)2(H2O)6]2+ with Mo(CO)6 or metallic Mo under hydrothermal conditions (140 °C, 4 M HCl) gives oxido-sulfido cluster aqua complex [Mo3(μ3-S)(μ-O)2(μ-S)(H2O)9]4+ (1). Similarly, [W3(μ3-S)(μ-O)2(μ-S)(H2O)9]4+ (2) is obtained from [W2O2(μ-S)2(H2O)6]2+ and W(CO)6. While reaction of [Mo2O2(μ-S)2(H2O)6]2+ with W(CO)6 mainly proceeds as simple reduction to give 1, [W2O2(μ-S)2(H2O)6]2+ with Mo(CO)6 produces new mixed-metal cluster [W2Mo(μ3-S)(μ-O)2(μ-S)(H2O)9]4+ (3) as main product. From solutions of 1 in HCl supramolecular adduct with cucurbit[6]uril (CB[6]) {[Mo3O2S2(H2O)6Cl3]2CB[6]}Cl2⋅18H2O (4) was isolated and structurally characterized. The aqua complexes were converted into acetylacetonates [M3O2S2(acac)3(py)3]PF6 (M3 = Mo3, W3, W2Mo; 5a-c), which were characterized by X-ray single crystal analysis, electrospray ionization mass spectrometry and 1H NMR spectroscopy. Crystal structure of (H5O2)(Me4N)4[W3(μ3-S)(μ2-S)(μ2-O)2(NCS)9] (6), obtained from 2, is also reported. 相似文献
13.
U. Casellato D. Fregona S. Tamburini P.A. Vigato R. Graziani 《Inorganica chimica acta》1985,110(1):41-46
Uranyl(VI) and thorium(IV) complexes of the type UO2(NO3)2(L1)2, UO2(NO3)2(L2)2, UO2(CH3COO)2L1, UO2(CH3COO)2L2, Th(NO3)4(L1)2 and Th(NO3)4(L2)2 (L1 = (2-nitro)phenyl-bis-phenyl phosphine oxide, L2 = triferrocenylphosphine oxide) are reported, together with their physico-chemical properties.The crystal structure of UO2(NO3)2(L1)2 is also reported. The crystals are monoclinic, space group P21/n with a = 17.78(1), b = 13.88(1), c = 17.37(1) Å, β = 114.8(1)° for Z = 4. The uranium atom is 8-coordinated, the uranyl(VI) group being equatorially surrounded by an irregular hexagon of six oxygen atoms from two trans neutral ligands and two nitrato groups. 相似文献
14.
超微粒TiO2对U937细胞光杀伤效应及机理研究 总被引:7,自引:0,他引:7
超微粒TiO2经光催化氧化后对U937白血病细胞有明显的杀伤作用,DNA琼脂糖凝胶电泳图证明了光激发TiO2能够损伤细胞内的DNA,从而导致细胞死亡,提出了一种杀伤癌细胞的新思路. 相似文献
15.
Masahiro Ebihara Mitsuko Nomura Shogo Sakai Takashi Kawamura 《Inorganica chimica acta》2007,360(7):2345-2352
Reaction of tetrathiafulvalene carboxylic acid (TTFCO2H) with paddlewheel dirhodium complex Rh2(ButCO2)4 yielded TTFCO2-bridged complexes Rh2(ButCO2)3(TTFCO2) (1) and cis- and trans-Rh2(ButCO2)2(TTFCO2)2 (cis- and trans-2). Their triethylamine adducts [1(NEt3)2] and cis-[2(NEt3)2] were purified and isolated with chromatographic separation, and characterized with single crystal X-ray analysis. Trans-[2(NEt3)2] is not completely separated from a mixture of cis- and trans-[2(NEt3)2], but its single crystals were obtained from a solution of the mixture. A three-step quasi-reversible oxidation process was observed for 1 in MeCN. The first two steps correspond to the oxidation of the TTFCO2 moiety and the last one is the oxidation of the Rh2 core. The oxidation of cis-2 is observed as a two-step process with very similar E1/2 values to those of the first two processes for 1. Both 1+ and cis-22+ in MeCN at room temperature show isotropic ESR spectra with a g value of 2.008 and aH = 0.135 mT for two equivalent H atoms and aH = 0.068 mT for one H atom. The redox and ESR data of cis-2 suggest that the intramolecular interaction between the TTF moieties is very small. 相似文献
16.
Athanassios K. Boudalis Vassilis Tangoulis Aris Terzis Spyros P. Perlepes 《Inorganica chimica acta》2004,357(5):1345-1354
Two synthetic procedures have been employed that allow access to the new tetranuclear cluster [Fe4O2(O2CMe)6(N3)2(phen)2] (1), where phen is 1,10-phenanthroline. Complex 1 · 3MeCN displays an unusual structural asymmetry (observed for the second time) in its [Fe4O2]8+ core that can be considered as a hybrid of the bent (butterfly) and planar dispositions of four metal ions seen previously in such compounds with transition metals. Complex 1 has been characterized by variable-temperature magnetic susceptibility studies, and by IR and variable-temperature 57Fe Mössbauer spectroscopies. Magnetochemical data reveal a diamagnetic ground state (S=0) with antiferromagnetic body-body and body-wingtip interactions between the iron(III) ions of the butterfly core (Jbb=−11 cm−1, Jwb=−70 cm−1). Magnetochemical and Mössbauer studies on 1 show that its structural asymmetry has practically no influence on these properties compared with the more symmetric types. 相似文献
17.
Thomas C.W. Mak 《Inorganica chimica acta》1985,109(2):131-133
The title compound has been synthesized and subjected to crystal structure analysis. Mr = 548.50, m.p. 108.1 °C (decom.), orthorhombic, Im2m,a = 7.006(2), b = 8.938(2), c = 13.619(2) Å V = 852.8(3) Å3, Z = 2, Dx = 2.136, Dm, (flotation in CCl4/CH2I2) = 2.128 g cm?3, λ(Mo-Kα) = 0.71069 Å, μ = 90.79 cm?1, F(000) = 519.89, T = 295 K, final RF = 0.036 and RG = 0.044 for 566 observed reflections. The discrete [UO2F4(H20)]2? anion has site symmetry m2m, its virtually linear uranyl moiety being surrounded by fluoro and aquo ligands occupying the vertices of a pentagon in the equatorial plane. Watet molecules serve to link the complex anions by hydrogen bonds into layers, between which the organic cations are accommodated. 相似文献
18.
The presence of prostaglandins (PGs) was determined in gastric juice obtained from 3 conscious dogs, provided with a chronic gastric fistula. Outputs of acid (mequiv min?1) and PGs (pg min?1) were measured in gastric secretions stimulated by pentagastrin (100 or 200 ng kg?1min?1). Prostaglandin activity was estimated, after extraction and thin layer chromatography, by radioimmuno-assay of the PGB formed by treatment with alkali. Tritiated PGs were added to gastric juice for the purpose of correcting for PGs recovery. Using this method, the minimum mass of PGB which could be satisfactorily distinguished from zero was 25 pg. Prostaglandins A2 and E2 were present in pentagastrin-activated gastric secretions and averaged (mean ± SE, n = 8) 200.7 ± 18.1 and 260.1 ± 18.0 pg min?1 respectively. The identity of PGA2 and PGE2 was confirmed by gas liquid chromatography combined with mass spectrometry. The amount of PGE2 converted to PGA2 during extraction, separation and conversion procedures was estimated from the amount of [3H] PGA2 found when only [3H] PGE2 had been added to a sample of gastric juice and averaged 14.5% ± 2.0. Our preliminary results support the possibility that PGE2 and PGA2 may be of physiological importance in the regulation of canine gastric secretions. 相似文献
19.
Suzanne Ferrere 《Inorganica chimica acta》2002,329(1):79-92
Ultrafast electron transfer in the dye sensitized solar cell (DSSC) has made it possible to use iron(II) polypyridyl complexes as photosensitizers [J. Am. Chem. Soc. 120 (1998) 843]. Although ruthenium(II) polypyridyl complexes comprise an extensively studied and widely utilized photochemical system, comparatively little is known about the photoproperties of their iron analogues. The syntheses and solution properties of the complexes [FeII(L)2(CN)2] and [FeIIL3] for a series of L, where L is a 2,2′-bipyridine derivative, are presented here. We compare the solvatochromism of [FeII(4,4′-dicarboxylic acid-2,2′-bipyridine)2(CN)2] to [FeII(4,4′-dimethyl-2,2′-bipyridine)2(CN)2] and discuss general trends in the electrochemistry and absorption properties within the series. The solvatochromism of these complexes is discussed in terms of their use in a dye sensitized TiO2 solar cell. 相似文献
20.
Reaction of HSi(OEt)3 with IrCl(CO)(PPh3)2 (5:1 molar ratio) at room temperature for 1 h gives IrCl(H){Si(OEt)3}(CO)(PPh3)2 (1), which is observed by the 1H and 31P{1H} NMR spectra of the reaction mixture. The same reaction, but in 20:1 molar ratio at 50 °C for 24 h produces IrCl(H)2(CO)(PPh3)2 (2) rather than the expected product Ir(H)2{Si(OEt)3}(CO)(PPh3)2 (3) that was previously reported to be formed by this reaction. Accompanying formation of Si(OEt)4, (EtO)3SiOSi(OEt)3, and (EtO)2HSiOSi(OEt)3 is observed. On the other hand, trialkylhydrosilane HSiEt3 reacts with IrCl(CO)(PPh3)2 (10:1 molar ratio) at 80 °C for 84 h to give Ir(H)2(SiEt3)(CO)(PPh3)2 (4) in a high yield, accompanying with a release of ClSiEt3. 相似文献