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101.
A series of pentacarbonyl complexes of chromium and molybdenum with unicoordinated-diphosphines, M(CO)5(η1-P-P) (P-P = dppe, dppp, dppb) has been prepared by amine oxide-induced phosphine substitution of the binary carbonyls. The basicity of the pendant phosphine groups was demonstrated by their ready conversion to the diphosphine-bridged heterobimetallic complexes (OC)5M(μ-P-P)M′(CO)5 (M, M′= Cr, Mo, W; M ≠ M′) in the presence of MCO)5(CH3CN). The complexes were characterized by IR and NMR (1H and 31P-{1H}) spectroscopy. 相似文献
102.
The specific adsorption of anions (HSO(4)(-), H(2)PO(4)(-), and Cl(-)) was studied at Fe(2)O(3), ZnO, and CuO surfaces by the radiotracer technique in strongly acidic medium (1 M HClO(4)). A significant specific adsorption of HSO(4)(-) and H(2)PO(4)(-) ions was found in all cases studied while no measurable adsorption of Cl(-) ions was observed. In the cases of ZnO and CuO, the specific adsorption takes place over the course of continuous dissolution of the oxide. Copyright 2000 Academic Press. 相似文献
103.
We synthesised and used new type of quaternary ammonium salt [S-(-)-2-hydroxymethyl-1,1-dimethylpyrrolidinium tetrafluoroborate] as effective additive to acidic background electrolytes. We used this quaternary ammonium salt as effective agent for capillary zone electrophoresis separation of model mixture of five tricyclic antidepressants (amitriptyline, nortriptyline, imipramine, desipramine and clomipramine) as model analytes. We observed that addition of S-(-)-2-hydroxymethyl-1,1-dimethylpyrrolidinium tetrafluoroborate ([HMDP](+) [BF(4)](-)) to acidic background electrolytes leads to suppression of magnitude of electroosmotic flow (EOF) and gradually change the direction of the EOF. Baseline separation of five TAs was achieved by using of 91.1 mmol L(-1) (20 gL(-1)) of [HMDP](+) [BF(4)](-) in 25 mmol L(-1) sodium phosphate pH 2.5, where electroosmotic mobility was -11.3 x 10(-9) m(2) V(-1) s(-1). We achieved baseline separation of five TAs with using of [HMDP](+) [BF(4)](-) as water solution too. We observed that [HMDP](+) [BF(4)](-) can be used as buffer additive, which offers relatively smaller anodic electroosmotic flow instead of cationic surfactants that are mostly used for genarating of anodic electroosmotic flow in capillary electrophoresis. 相似文献
104.
A bimetallic Ni-Al (2.5087(15) A) complex with an agostic alpha-C-H, [eta-C5H4CH=N(C6F5)]Fe[eta-C5H4PPh2]Ni(AlMe3), has been isolated and crystallographically established. The complex is active towards ethylene oligomerization/polymerization under moderate conditions. 相似文献
105.
Novel Au/La‐SrTiO3 microspheres: Superimposed Effect of Gold Nanoparticles and Lanthanum Doping in Photocatalysis 下载免费PDF全文
Novel multielement Au/La‐SrTiO3 microspheres were synthesized by a solvothermal method using monodisperse gold and La‐SrTiO3 nanocrystals as building blocks. The porous Au/La‐SrTiO3 microspheres had a large surface area of 94.6 m2 g?1. The stable confined Au nanoparticles demonstrated strong surface plasmon resonance effect, leading to enhanced absorption in a broad UV/Vis/NIR range. Doping of rare‐earth metal La also broadened the absorption band to the visible region. Both the conduction and valence bands of Au/La‐SrTiO3 microspheres thus show favorable potential for proton reduction under visible light. The superimposed effect of Au nanoparticles and La doping in Au/La‐SrTiO3 microspheres led to high photocurrent density in photoelectrochemical water splitting and good photocatalytic activity in photodegradation of rhodamine B. The photocatalytic activities are in the order of the following: Au/La‐SrTiO3 microspheres>Au/SrTiO3 microspheres>La‐SrTiO3 microspheres>SrTiO3 microspheres. 相似文献
106.
G. Horányi 《Journal of Solid State Electrochemistry》2003,7(5):309-312
The pH and concentration dependence of the adsorption of sulfate ions on powdered Bi2O3 was studied by a radiotracer technique in the presence of a large excess of perchlorate supporting electrolyte. It was found
that, similar to other oxides such as Al2O3, Cr2O3 and Fe2O3, the extent of adsorption is determined by the protonation of the Bi2O3 surface. The redox transformations of Bi adatom layers are discussed in the light of the results obtained. It is established
that for the interpretation of the redox processes occurring at the Bi/electrolyte interface the role of protonation of the
oxide formed and the anion adsorption induced by the oxide layer should be taken into consideration.
Electronic Publication 相似文献
107.
H. S. O. Chan S. C. Ng S. H. Seow W. S. Sim T. S. A. Hor 《Journal of Thermal Analysis and Calorimetry》1993,39(2):177-185
The thermal characteristics of polyaniline (PANI), poly(o-aminobenzoic acid) (POABAC) and poly(o-aminobenzyl alcohol) (POABOL) are determined and compared by thermogravimetry (TG) and differential scanning calorimetry (DSC). The higher thermal stability of POABOL is attributed to heat-induced condensation between the polymer chains. The DSC results suggest both intra- and inter-molecular interaction in the form of hydrogen bonding due to the substituent group in POABAC and POABOL. These interactions, however, occur mainly in the doped from and is greatly reduced when the dopant is expelled from the system at higher temperatures.
Zusammenfassung Es wurden die thermischen Eigenschaften von Polyanilin (PANI), Poly(o-aminobenzoylsäure) (POABAC) und Poly(o-aminobenzylalkohol) (POABOL) ermittelt und mittels TG und DSC miteinander verglichen. Die höhere Thermostabilität von POABOL wird der wärmeinduzierten Kondensationsreaktion zwischen den Polymerketten zugeschrieben. Die DSC-Resultate weisen auf sowohl intra- als auch intermolekulare Wechselwirkungen in Form von Wasserstoffbrückenbindungen infolge der Substituenten in POABAC und POABOL hin. Diese Wechselwirkungen treten hauptsächlich in der dotierten Form auf und werden in großem Maße reduziert, wenn die Dotierungsmittel bei höheren Temperaturen ausgetrieben werden.相似文献
108.
Tereza Košutová Lukáš Horák Artem Shelemin Mykhailo Vaidulych Jan Hanuš Hynek Biederman Ondřej Kylián Pavel Solař Miroslav Cieslar Andrei Choukourov Milan Dopita 《Surface and interface analysis : SIA》2020,52(12):1023-1028
Metal-polymer nanocomposites have gained increasing attention due to the wide potential applications field. Synthesis of nanoparticles from the gas phase is an intensively studied alternative to the chemical preparation methods. We present a one-step procedure that combines magnetron-based gas aggregation cluster source of silver nanoparticles and simultaneous plasma-enhanced chemical vapour deposition of hexamethyldisiloxane (HMDSO). The key parameter of the process, significantly influencing the morphology and microstructure of studied nanoparticles, was found to be the amount of HMDSO added to the deposition chamber as witnessed by small angle X-ray scattering and X-ray diffraction methods combined with transmission electron microscopy and UV–Vis spectrophotometry. The presence of HMDSO in the chamber leads to changes in the size distribution and also in the architecture of prepared nanoparticles. The increasing amount of HMDSO induces the formation of individual core-shell nanoparticles, chains of core-shell nanoparticles, and for the highest concentration of HMDSO, the synthesis of multi-core-shell nanoparticles. The size of crystallites in the silver cores of nanoparticles decreases with addition of HMDSO, which prevents further aggregation. 相似文献
109.
Vojtěch Hamala Andrea Martišová Lucie Červenková Šťastná Jindřich Karban Andrej Dančo Adam Šimarek Martin Lamač Michal Horáček Tamara Kolářová Roman Hrstka Róbert Gyepes Jiří Pinkas 《应用有机金属化学》2020,34(11):e5896
Ruthenium tetrazene complexes with general formula [Cp*RuCl(1,4-R2N4)] (Cp* = η5-C5Me5), where R = benzyl ( 1 ), 2-fluorobenzyl ( 2 ), β-d -glucopyranosyl-unprotected ( 3a ) and acyl-protected ( 3b – d ), 2-acetamido-β-d -glucopyranosyl-unprotected ( 4a ) and acyl-protected ( 4b – d ), propyl-β-d -glucopyranoside-unprotected ( 5a ), and O-acetylated ( 5b ), were synthesized and characterized using nuclear magnetic resonance and electrospray ionization–mass spectrometry. In addition, the molecular structure of 3b was determined using X-ray crystallography. The cytotoxicity of complexes against ovarian (A2780, SK-OV-3) and breast (MDA-MB-231) cancer cell lines and noncancerous cell line HEK-293 was evaluated and compared to cisplatin activity. The carbohydrate-modified complexes bearing acyl-protecting groups exhibited higher efficacy (in low micromolar range) than unprotected ones, where the most active 4d was superior to cisplatin up to five times against all investigated cancer cell lines; however, no significant selectivity was achieved. The complex induced apoptotic cell death at low micromolar concentrations (0.5 μM for A2780 and HEK293; 2 μM for SK-OV-3 and MDA-MB-231). 相似文献
110.