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991.
Fabrication, Characterization and Electrocatalysis of an Ordered Carbon Nanotube Electrode 总被引:3,自引:0,他引:3
A method for fabrication of ordered carbon nanotube (CNT) film,which was template-synthesized within the highly ordered pores of a commercially available alumina template membrane,modified glassy carbon(CNT/GC) electrode was established.The CNT/GC electrode showed excellent electrocatalytic activity toward dopamine electrochemical reaction without introducing any electrochemically active group into CNT film or activating any electrochemically active group into CNT film or activating the electrode electrochemically.DA undergoes ideal reversible electrochemical reaction on CNT/GC electrode at low scan rate(≤20mV/s) with an excellent reproducibility and stability.The CNT/GC electrode might be used in biosensors because the highly ordered CNT may present a steric effect on more efficient redox reactions of biomolecules. 相似文献
992.
993.
A.R. László Bursics Martin Murray F. Gordon A. Stone 《Journal of organometallic chemistry》1976,111(1):31-42
Bis(cyclopentadienyl)mercury readily undergoes Diels—Alder reactions with RCCR (R = CO2Me or CF3), CF3CFCFCF3, CF3CFCF2, (CF3)2CC(CN)2, C2(CN)4 and PhO to give stable adducts characterised by1H, 19F and 13C NMR, spectroscopy. Similar reactions of CF3CCCF3 and CF3CFCFCF3 with the cyclopentadiene derivatives Me3MC5H5 and (Me3M)2C5H4 (M = Si, Sn) are also described. 相似文献
994.
Martin Lindner 《manuscripta mathematica》1978,25(1):47-60
Let 0 be the local ring of a simple singularity defined over the complex numbers and the dimension of its versal deformation space. Than it is well known that any nearby singularity in this space is also simple and has smaller unfolding dimension in the hierarchy of simple singularities. In particular this implies that the =max-stratum consists just of one point namely the given singularity. We want to generalize this concept as we are interested in families of varieties with formal unchanged singularities. For this we introduce in quite generality the notion of flat T1-stabi1ity which may be checked for any k- algebra 0 where k is for simplicity an algebraically closed field of à priori arbitrary characteristics. We call 0 formal flat T1 stable or for short flat T1-stable if the following is true: if R is any deformation of 0 over an Artin local finite k-algebra A and if T1(R/A,R) is A-flat than R is isomorphic to the trivial deformation
. T1(R/A,R) is the first cotangent module of R over A with values in R. Obviously the simple singularities Ak, Dk, E6, E7, E8 fulfill this criterion over C but we look also at fibres of arbitrary stable map germs, generic singularities of algebraic varieties where we have to modify this notion in order to deal with wild ramification and to quasihomo-genous hypersurface singularities where it functorializes because in this case T1 commutes with arbitrary base change. The notion of flat T1-stable singularities is closely related to questions of existence of equisingular families and is used in[12] and [5], [6] to stratify certain Hilbert schemes. 相似文献
995.
Reaction of benzotriazol‐1‐yl acetone 1 with phenyl isothiocyanate followed with α‐chloroacetone or ethyl‐α‐chloroacetate afforded 2‐anilinothiophenes 3 or 4 , respectively. Treatment of 3 with malononitrile at different reaction conditions afforded 6 or 7 . Reaction of 1 with CS2 in DMF and phenacylbromide afforded S‐alkylated thiophene 10 . Reactions of the latter compound with different active methylene nitriles afforded thienylthiopyridine derivatives 14 and 15 . Condensation of 10 with hydrazine hydrate afforded hydrazon derivative 16 . Reaction of thiophene 17 with formamide in DMF afforded 19 which converted to N‐thienylpyrimidine 20 when treated with malononitrile. The structure of the newly synthesized compounds has been established on the basis of their analytical and spectral data. The compounds were also investigated for antibacterial and antifungal activities. 相似文献
996.
Responsive polymers have been the focus of many studies during the past decade because of their ability to change according to environmental stimuli. In this paper, we report on the development of a method to synthesize a pH/temperature‐sensitive linear copolymer, poly(N‐isopropylacrylamide‐ co‐acrylic acid)(poly(NIPAAm‐co‐AAc)), with a molecular weight of about 106–105 Da in water using azobisisobutyronitrile (AIBN) as the initiator. The effects of the following on the lower critical solution temperature (LCST) of the copolymer and homopolymer of NIPAAm were investigated: the type of buffer salts and pH changes of test solutions, molecular weight and concentration of homopolymer/copolymer solutions, and AAc monomer molar feed ratio (mol%). The effects of different synthesis methods on the molecular weight and on the AAc content were also evaluated. The mechanism of action in environments with different pH values is discussed. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
997.
Seung‐Chul Choi Jaejung Ko Sang Ook Kang Won‐Sik Han Ki‐Young Choi 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):m85-m87
The copper(II) ion in the syn–anti carboxylate‐bridged one‐dimensional zigzag chain title complex, {[Cu(C16H18N3O2)]ClO4}n, exhibits a distorted trigonal–bipyramidal environment. Two N atoms and one carboxylate O atom of the ligand form the basal plane, while the axial positions are filled by an N atom of the ligand and one O atom belonging to the carboxylate group of an adjacent molecule. The crystal packing is enhanced by C—H⋯O(perchlorate) hydrogen bonds. 相似文献
998.
Nuclear Overhauser Effect (NOE) methods in NMR are an important tool for 3D structural analysis of small molecules. Quantitative NOE methods conventionally rely on reference distances, known distances that have to be spectrally separated and are not always available. Here we present a new method for evaluation and 3D structure selection that does not require a reference distance, instead utilizing structures optimized by molecular mechanics, enabling NOE evaluation even on molecules without suitable reference groups.A quantitative Nuclear Overhauser Effect (NOE) analysis approach that avoids the use of and internal reference distance to perform molecular configuration selection. 相似文献
999.
Treatment of HgCl(2) with 2-LiC(6)H(4)PPh(2) gives [Hg(2-C(6)H(4)PPh(2))(2)] (1), whose phosphorus atoms take up oxygen, sulfur, and borane to give the compounds [Hg[2-C(6)H(4)P(X)Ph(2)](2)] [ X = O (3), S (4), and BH(3) (5)], respectively. Compound 1 functions as a bidentate ligand of wide, variable bite angle that can span either cis or trans coordination sites in a planar complex. Representative complexes include [HgX(2) x 1] [X = Cl (6a), Br (6b)], cis-[PtX(2) x 1] [X = Cl (cis-7), Me (9), Ph (10)], and trans-[MX(2) x 1] [X = Cl, M = Pt (trans-7), Pd (8), Ni (11); X = NCS, M = Ni (13)] in which the central metal ions are in either tetrahedral (6a,b) or planar (7-11, 13) coordination. The trans disposition of 1 in complexes trans-7, 8, and 11 imposes close metal-mercury contacts [2.8339(7), 2.8797(8), and 2.756(8) A, respectively] that are suggestive of a donor-acceptor interaction, M --> Hg. Prolonged heating of 1 with [PtCl(2)(cod)] gives the binuclear cyclometalated complex [(eta(2)-2-C(6)H(4)PPh(2))Pt(mu-2-C(6)H(4)PPh(2))(2)HgCl] (14) from which the salt [(eta(2)-2-C(6)H(4)PPh(2))Pt(mu-2-C(6)H(4)PPh(2))(2)Hg]PF(6) (15) is derived by treatment with AgPF(6). In 14 and 15, the mu-C(6)H(4)PPh(2) groups adopt a head-to-tail arrangement, and the Pt-Hg separation in 14, 3.1335(5) A, is in the range expected for a weak metallophilic interaction. A similar arrangement of bridging groups is found in [Cl((n)Bu(3)P)Pd(mu-C(6)H(4)PPh(2))(2)HgCl] (16), which is formed by heating 1 with [PdCl(2)(P(n)()Bu(3))(2)]. Reaction of 1 with [Pd(dba)(2)] [dba = dibenzylideneacetone] at room temperature gives [Pd(1)(2)] (19) which, in air, forms a trigonal planar palladium(0) complex 20 containing bidentate 1 and the monodentate phosphine-phosphine oxide ligand [Hg(2-C(6)H(4)PPh(2))[2-C(6)H(4)P(O)Ph(2)]]. On heating, 19 eliminates Pd and Hg, and the C-C coupled product 2-Ph(2)PC(6)H(4)C(6)H(4)PPh(2)-2 (18) is formed by reductive elimination. In contrast, 1 reacts with platinum(0) complexes to give a bis(aryl)platinum(II) species formulated as [Pt(eta(1)-C-2-C(6)H(4)PPh(2))(eta(2)-2-C(6)H(4)PPh(2))(eta(1)-P-1)]. Crystal data are as follows. Compound 3: monoclinic, P2(1)/n, with a = 11.331(3) A, b = 9.381(2) A, c = 14.516 A, beta = 98.30(2) degrees, and Z = 2. Compound 6b x 2CH(2)Cl(2): triclinic, P macro 1, with a = 12.720(3) A, b = 13.154(3) A, c = 12.724(2) A, alpha = 92.01(2) degrees, beta = 109.19(2) degrees, gamma = 90.82(2) degrees, and Z = 2. Compound trans-7 x 2CH(2)Cl(2): orthorhombic, Pbca, with a = 19.805(3) A, b = 8.532(4) A, c = 23.076(2) A, and Z = 4. Compound 11 x 2CH(2)Cl(2): orthorhombic, Pbca, with a = 19.455(3) A, b = 8.496(5) A, c = 22.858(3) A, and Z = 4. Compound 14: monoclinic, P2(1)/c, with a = 13.150(3) A, b = 12.912(6) A, c = 26.724(2) A, beta = 94.09(1) degrees, and Z = 4. Compound 20 x C(6)H(5)CH(3).0.5CH(2)Cl(2): triclinic, P macro 1, with a = 13.199(1) A, b = 15.273(2) A, c = 17.850(1) A, alpha = 93.830(7), beta = 93.664(6), gamma = 104.378(7) degrees, and Z = 2. 相似文献
1000.
Guey‐Sheng Liou Sheng‐Huei Hsiao 《Journal of polymer science. Part A, Polymer chemistry》2002,40(15):2564-2574
A new N‐phenylated amide (N‐phenylamide) unit containing aromatic diamine, N,N′‐bis(3‐aminobenzoyl)‐N,N′‐diphenyl‐1,4‐phenylenediamine, was prepared by the condensation of N,N′‐diphenyl‐1,4‐phenylenediamine with 3‐nitrobenzoyl chloride, followed by catalytic reduction. Two series of organosoluble aromatic poly(N‐phenylamide‐imide)s and poly(N‐phenylamide‐amide)s with inherent viscosities of 0.58–0.82 and 0.56–1.21 dL/g were prepared by a conventional two‐stage method and the direct phosphorylation polycondensation, respectively, from the diamine with various aromatic dianhydrides and aromatic dicarboxylic acids. All polyimides and polyamides are amorphous and readily soluble in many organic solvents such as N,N‐dimethylacetamide and N‐methyl‐2‐pyrrolidone. These polymers could be solution cast into transparent, tough, and flexible films with high tensile strengths. These polyimides and polyamides had glass‐transition temperatures in the ranges of 230–258 and 196–229 °C, respectively. Decomposition temperatures of the polyimides for 10% weight loss all occurred above 500 °C in both nitrogen and air atmospheres. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2564–2574, 2002 相似文献