共查询到20条相似文献,搜索用时 46 毫秒
1.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1989,45(2):159-161
Pressure effects on the MLCT bands of the pyrazine- and 4-cyanopyridine-pentacyanoferrate(II) anions have been established. The relation of these piezochromic effects to the solvatochromism of each complex is put into the correlation between these parameters developed for other d6 ternary complexes. The conformance of piezochromic and solvatochromic efrects on MMCT bands for diiron and diruthenium mixed valence complexes to this correlation is examined. 相似文献
2.
Poly(AN—co—St) (PAS) and poly(AN—St—MMA)(PASM) were synthetized by emulsion polymerisation. The glass transition temperatures (Tg) of the copolymers and the relationship between Tg and the components of the copolymers were investigated by differential scanning calorimetry. The results show that Tg for the AN—St bipolymers has apeak value in the range 115–118°C at a content of 50 mass% St. When methyl methacrylate was added, the Tg of the terpolymer was decreased by about 2–6°C.The thermostability and the activation energy E of degradation were determined by thermogravimetric analysis.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
3.
Miftakhov M. S. Ermolenko M. S. Gaisina I. N. Kuznetsov O. M. Selezneva N. K. Yusupov Z. A. Muslukhov R. R. 《Russian Chemical Bulletin》2001,50(6):1101-1106
Alkylation of (1R,2R,5R)-2-benzenesulfonyl-6,8-dioxa-bicyclo[3.2.1]octan-3-one, which is accessible from levoglucosan, afforded (1R,2R,5R)-2-benzenesylfonyl-2,4,4-trimethyl-6,8-dioxabicyclo[3.2.1]octan-3-one. This was further converted into (1S,2R,3S,5R)-2,4,4-trimethyl-6,8-dioxabicyclo[3.2.1]octan-3-ol representing the C9—C13 fragment of acutiphycin molecule. 相似文献
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5.
Biologically, Nitric Oxide(NO) was first characterized in 1987 as an endothelial-derived relaxing factor.It regulates vascular tone, acts as a neuronal signal in the gastrointestinal tract and central nervous system. 相似文献
6.
H. Y. Wang M. L. Pan Y. L. Oliver Su S. C. Tsai C. H. Kao S. S. Sun W. Y. Lin 《Journal of Analytical Chemistry》2011,66(4):415-420
Carbamazepine is a widely used anti-epileptic drug with narrow therapeutic range. Many methods have been developed for monitoring
the serum drug level. Differential pulse voltammetry (DPV), an electrochemical method advantaged by simple, inexpensive, and relatively short analysis time, has recently been developed
for carbamazepine detection. We used a newly developed DPV method with glassy carbon as a working electrode to determine the
carbamazepine level. The performance of DPV is compared with the widely used fluorescence polarization immunoassay (FPIA) technique in precision, accuracy, linearity and detection limit. The precision, linearity and accuracy of the DPV and FPIA
techniques were comparable at most clinical used levels. The detection limit was 1 μg/mL for the DPV technique and 0.5 μg/mL
for the FPIA technique. The performance of the DPV technique was within the FDA guidelines for bioanalytical methods, which
ensures the clinical applicability of the DPV technique. The DPV technique may have the potential to be a good alternative
for carbamazepine analysis. 相似文献
7.
O. B. Abdyev 《Polymer Science Series B》2010,52(3-4):198-202
The free-radical copolymerization of L-(—)-menthyl methacrylate with o- and p-acetylphenyl (meth)acrylates is performed to obtain new carbonyl-containing optically active copolymers. It is shown that the reactivity ratios and the yield of copolymers are lower for o-acetylphenyl methacrylate than those for the corresponding para isomer because of the steric hindrance from acetyl substituents in phenyl rings. The optical activity of the synthesized copolymers is estimated. 相似文献
8.
The selective low-temperature (40—70 °C) catalytic oxidation of methanol, propan-1-ol, and propan-2-ol in the presence of the tetraaquapalladium(ii) complex and iron(iii) ions and/or molecular oxygen as cooxidants was studied. The corresponding carbonyl compound is the product of alcohol oxidation. The kinetic regularities of the reaction were established. In the reaction mechanism proposed, the key step is palladium(i) formation. 相似文献
9.
Results of dielectric relaxation studies will be discussed. It turns out that competition of electric and structural relaxation coins permittivity and as a result conductivity mechanism at low temperature. It dominates long-ranging relaxation in the molten state. In the opposite limit of temperature, cross-linked poly(ethylene oxide) (PEO) with low mesh size can be transferred into super-cooled liquid state. Then, PEO behaves like a hydrogen-bonded liquid since crystallization is strongly suppressed. As a result, one observes slow Debye-like relaxation at low temperature. Beyond the low-frequency region, there appears an extended region between crossings of impedance components, where Z′ ≈ Z″ at acceptable approximation. It is coined by damped oscillation under action of the electric field. These effects lessen with increasing mesh size of the sample as clearly shown by M″(ω) spectra. The dipole moment of the PEO samples in molten state decreases only slightly with increasing mesh size. 相似文献
10.
AnticancerDrugs(V)─—SynthesisofEtoposideDerivativesTIANXuan,YANZe-qun,LIJin-xinandCHENYao-zu(NationalLaboratoryofAppliedOrgan... 相似文献
11.
Vesna V. Vodnik Jasna V. Vuković Jovan M. Nedeljković 《Colloid and polymer science》2009,287(7):847-851
The optical properties of silver nanoparticles embedded in poly(methylmethacrylate) (PMMA) was investigated as well as the
influence of silver nanoparticles on the thermal properties of polymer matrix. The average size and particle size distribution
of silver nanoparticles was determined using transmission electron microscopy. The obtained transparent nanocomposite films
were optically characterized using UV-Vis and FTIR spectroscopy. Thermal stability of polymer matrix was improved upon incorporation
of small amount of silver nanoparticles. Also, silver nanoparticles have pronounced effect on thermo-oxidative stability of
PMMA matrix. The glass transition temperatures of nanocomposites are lower compared to the pure polymer. 相似文献
12.
In our laboratory, the isomerization/chlorination of a variety of O,O-dialkyl phosphoro(-no)thionates 1 with phosphorus oxychloride have been systematically studied. It was found that when R' equals aryloxy[1], alkylthio[2], arylthio[2], dialkylamino[3], phenyl[4], methyl[5],and nitrogen heterocyclic group[6] in 1,respectively, this reaction can proceed smoothly and gives the desired products 2 and 3. Hence, it provides a general synthitic method for S-alkyl thiophosphoro(-no)chloridates, especially for the asymmetric ones. 相似文献
13.
A few new spectrophotometric methods for the determination of trace amounts of tin(IV) have been developed based on the reaction of tin(Ⅳ) with tungstate and basic dyes(BD), which consists of rhodamine B(RB),butylrhodamine B(BRB) and nile blue(NB),to form ion-associations complexes of the kind in the presence of polyvinyl alcohol(PVA). 相似文献
14.
This article describes the formal synthesis of quebrachamine based on regio- and stereoselective hydrocyanation of 1,3-disubstituted allenes. Allenyl CC double bonds are effectively discriminated through Ni-catalyzed hydrocyanation and a CN group is utilized as a synthon of piperidine ring. Several steps from HCN adduct afforded known intermediates to quebrachamine. 相似文献
15.
Reaction of aminoethanol or aminophenol with aroyl chloride and ammonium thiocyanate under the condition of solid-liquid phase transfer catalysis using polyethylene glycol—600 (PEG—600) as the catalyst yielded N—aroyl—N′—hydroxyethyl (hydroxy phenyl) thiourea derivatives. The products have been characterised on the basis of analytical and spectral (IR and ′H—NMR) data. 相似文献
16.
The kinetics of oxidation of pyruvate by diperiodatoargentate( III) ion (DPA) has been studied spec-trophotometrically in alkaline medium. It was found that the reaction order with respect to both DPA and pyruvate is unity and the rate equation can be expressed asThe rate increases with the increase in [OH ] and decreases with the increase in [periodate]. There is a positive ionic strength effect in this reaction system. A mechanism has been proposed to explain the experimental results. The observed activation parameters are presented. 相似文献
17.
Science China Chemistry - Anti-Markovnikov hydroazidation of unactivated alkenes using ABX2014;N3 as an initiator has been developed at room temperature, wherein hydrogen azide (HN3) acts as both... 相似文献
18.
M. V. Moskalev A. A. Skatova V. A. Chudakova N. M. Khvoinova N. L. Bazyakina A. G. Morozov O. V. Kazarina A. V. Cherkasov G. A. Abakumov I. L. Fedushkin 《Russian Chemical Bulletin》2015,64(12):2830-2840
Digallane (dpp-bian)Ga—Ga(dpp-bian) (1) (dpp-bian is the 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) catalyzes the addition of 4-chloroaniline to some terminal alkynes RC≡CH (R = Bun, Ph, 4-MeC6H4). The reaction orders in each of the substrates were found for the reaction of phenylacetylene with 4-chloroaniline catalyzed by compound 1. The reaction of compound 1 with phenylacetylene in a molar ratio of 1: 10 led to 1-[N-(2,6-diisopropylphenyl)imino]-2-(1-phenylethylidene)acenaphthene (5) and the compound [C12H6(NC6H3Pr2 i)(PhC=CH2)(PhC=CH)]Ga(C≡CPh)2 (6). The reaction of digallane 1 with phenylacetylene and aniline in a stoichiometric ratio of 1: 2: 2 gave bis-anilide (dpp-bian)-Ga[N(H)Ph]2 (7) in 40% yield. The compound (PhC≡C)3Ga·THF (9) was obtained by the reaction of three equivalents of sodium phenylacetylide (prepared in situ from phenylacetylene and sodium) with one equivalent of GaCl3 in tetrahydrofuran. Compounds 5—7 and 9 were characterized by IR spectroscopy, 1H NMR spectroscopy was used to characterize products 5, 6, and 9, whereas EPR spectroscopy was used for amide 7. The structures of compounds 5—7 and 9 were determined by single crystal X-ray diffraction analysis. 相似文献
19.
《Journal of organometallic chemistry》1991,417(3):C47-C49
Diphenyl(trifluoromethyl)bismuth and phenylbis(trifluoromethyl)bismuth have been synthesized from Cd(Cf3)2 2CH3CN and the corresponding phenylbismuth halides. The reactions of the new compounds are similar to those of tris(perfluoroorgano)bismuth compounds and mixed phenyl-akyl bismuth derivatives. 相似文献
20.
Being widely used as good ligands,xanthates and related compounds have been extensively investigated.However,reports on Pt(Ⅱ) xanthates have been sparse so far.Watt et al.reported the synthesis and characterization of Pt(S_2COR)_2(R=Me,Et),but did not provide any absorption spectra of these complexes.We prepared twelve platinum (Ⅱ) xanthate complexes and examined their absorption spectra in detail. 相似文献