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1.
Synthesis and characterization of di- and trivalent pyrazolylborate β-diketonates and cyanometalates
Tang M Li D Mallik UP Zhang YZ Clérac R Yee GT Whangbo MH Mungalimane A Holmes SM 《Inorganic chemistry》2011,50(11):5153-5164
The syntheses, structures, and magnetic properties of a series of di- and trivalent hydridotris(3,5-dimethylpyrazol-1-yl)borate (Tp*) cyanomanganates are described. Treatment of tris(acetylacetonate)manganese(III) [Mn(acac)(3)] with KTp* and tetra(ethyl)ammonium cyanide affords [NEt(4)][(Tp*)Mn(II)(κ(2)-acac)(CN)] (1), as the first monocyanomanganate(II) complex; attempted oxidation of 1 with iodine affords {(Tp*)Mn(II)(κ(2)-acac(3-CN))}(n) (2) as a one-dimensional chain and bimetallic {[NEt(4)][(Tp*)Mn(II)(κ(2)-acac(3-CN))](2)(μ-CN) (3) as the major and minor products, respectively. A fourth complex, [NEt(4)][(Tp*)Mn(II)(η(2)-acac(3-CN))(η(1)-NC-acac)] (4), is obtained via treatment of Mn(acac(3-CN))(3) with KTp* and [NEt(4)]CN, while [NEt(4)](2)[Mn(II)(CN)(4)] (5) was prepared from manganese(II) trifluoromethanesulfonate and excess [NEt(4)]CN. Tricyanomanganate(III) complexes, [cat][(Tp*)Mn(III)(CN)(3)] [cat = NEt(4)(+), 7; PPN(+), 8], are prepared via sequential treatment of Mn(acac(3-CN))(3) with KTp*, followed by [NEt(4)]CN, or [cat](3)[Mn(III)(CN)(6)] with (Tp*)SnBu(2)Cl. Magnetic measurements indicate that 1, 2, and 4 contain isotropic Mn(II) (S = (5)/(2); g = 2.00) centers, and no long-range magnetic ordering is found above 1.8 K. Compounds 7 and 8 contain S = 1 Mn(III) centers that adopt singly degenerate spin ground states without orbital contributions to their magnetic moments. 相似文献
2.
《Tetrahedron letters》1987,28(51):6473-6474
The reaction of diphenyltin bis(dithiophosphates) with N-bromo- and N-iodosuccinimides afforded corresponding thiophosphorosulfenyl bromides and iodides, which reacted with a variety of nucleophiles such as thiol, dithiocarboxylic acid, amine and olefin to give novel unsymmetrical disulfides, sulfenamides and dithiophosphoric acid esters. 相似文献
3.
4.
Andreas Richter Steffen Howitz Dirk Kuckling Katja Kretschmer Karl-Friedrich Arndt 《Macromolecular Symposia》2004,210(1):447-456
This paper describes automatically and electronically controlled valves and microvalves based on smart hydrogels. The operating performance of such devices will be discussed in dependence on various design parameters. Furthermore, it will be shown that hydrogel based valves are showing an outstanding possibility of miniaturization, a leakage free switching behavior up to a pressure drop of 8.4 bar, and a pronounced particle tolerance. 相似文献
5.
A series of six-coordinate “half-sandwich” zirconocene phosphates and phosphonates have been synthesized by the reaction of
Cp2ZrCl2 with (diphenyl-, dibenzyl-)phosphate and methylphenylphosphinic acid under different conditions. All of the complexes were
characterized by elemental analysis, FT-IR and NMR (1H, 13C) spectroscopy. Except for complex 3, the structures of complexes 1, 2, 4, 5, and 6 were confirmed by X-ray crystallography. The structure analyses reveal that complexes 1, 2, and 3 are trinuclear complexes with fascinating μ3-oxygen bridging ligands, central to a Zr–O backbone (Cp2ZrCl2:ligand is 1:1) while complexes 4, 5, and 6 are centrosymmetric dinuclear complexes built up about the trapezoidal Zr2(μ2-OH)2 unit (Cp2ZrCl2:ligand is 1:2). 相似文献
6.
M. A. Bazhenova S. S. Bogush A. G. Herbst T. V. Demeshchik Yu. G. Komarovskaya V. S. Kurova M. D. Reshetova A. D. Ryabov E. S. Ryabova Yu. N. Frrsova 《Russian Chemical Bulletin》1996,45(10):2445-2451
Absract Simple methods have been developed for the preparation of a series ofn-alkylferrocenes H(CH2)
n
Fc (n = 3, 5–8, or 12) based on Friedel-Crafts acylation of ferrocenes followed by reduction of the corresponding ketones with Zn amalgam. The properties of H(CH2)
n
Fc and the corresponding ferrocenium ions in micellar aqueous solutions and the behavior of water-soluble cations H(CH2)
n
Fc+ in the absence of micelles were studied by cyclic voltammetry. In all cases, the formal redox potentials of ferrocenes (E
o) increase linearly asn increases up to 8. Whether micelles are present or not, the corresponding correlation equation has the following form:E
o= + n, where = 29 mV in all cases. The synthesis of (±)-1-ethyl-2-methylferrocene from racemic -dimethylaminoethylferrocene is reported.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2575–2581, October 1996. 相似文献
7.
Zh. A. Krasnaya E. O. Tret��yakova V. V. Kachala S. G. Zlotin 《Russian Chemical Bulletin》2011,60(10):2014-2020
Reactions of N-acetyl- and N-benzyl-4-piperidones with aminal of ??-dimethylaminoac-rolein yielded ketocyanines bearing piperidine cycle. Reaction of 3-dimethylamino-1,1,3-trimethoxypropane with 1-acetylpiperidin-4-ylidenemalononitrile in the presence of ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4), resulted in cross-conjugated ??,???-dimethylamino dinitrile. Protonation of ketocyanines bearing N-acetyl- and N-benzyl-piperidine cycles with Et2O·HBF4 (1 equiv.) furnished piperidinium salts, while protonation of the latter with Et2O·HBF4 (2 equiv.) afforded doubly charged 4-hydroxypolymethine salts. Unlike protonation, reaction of 3,5-bis(3-dimethylaminoprop-2-enylidene)-1-acetylpiperidin-4-one with Me2SO4 involved only the oxygen atom and led to a singly charged 4-methoxypolymethine salt. Methylation of 3,5-bis(3-dimethylaminoprop-2-enylidene)-1-benzylpiperidin-4-one with Me2SO4 (1 equiv.) involved cyclic nitrogen atom and resulted in piperidinium salt; heating of the latter with the excess of Me2SO4 afforded doubly charged bis-methoxysulfonate. Starting from 4-methoxytetrahydropyridinium salts, meso-methoxythiapentacarbocyanine dyes were synthesized. 相似文献
8.
Artamkina G. A. Shilova E. A. Shtern M. M. Beletskaya I. P. 《Russian Journal of Organic Chemistry》2003,39(9):1282-1291
Reactions of p- and m-diiodobenzenes, p,p'-diiodobiphenyl, and 1,3,5-triiodobenzene with anions derived from dicarbonyl(cyclopentadienyl)iron and pentacarbonylmanganese, catalyzed by palladium complexes, provide a successful route to mono-, di-, and trinuclear -aryl iron and manganese complexes. 相似文献
9.
Seiichiro Ogawa Yasushi Uematsu Satoshi Yoshida Naoko Sasaki Tetsuo Suami 《Journal of carbohydrate chemistry》2013,32(3):471-478
Abstract Pseudo-β-D (D-2) and L-fructopyranose (L-2), 1(S) and (1R)-(1,2/-3,4)-4-C-hydroxymethyl-1,2,3,4-cyclohexanetetrol, have been synthesized, starting from optically active endo-adducts of furan and acrylic acid, following the modified procedure used for the preparation of the racemic modification. It has been demonstrated that the D and L-enantiomers are nearly as sweet as D-fructose, and the former is somewhat sweeter than the latter. 相似文献
10.
Mohamed Tebbaa Ahmed El HakmaouiAhmed Benharref Mohamed Akssira 《Tetrahedron letters》2011,52(29):3769-3771
The aerial part of Dittrichia viscosa yielded two sesquiterpenes, isocostic acid (1) and ilicic acid (2), on multigram scale. These acids are appropriate starting materials for short and facile syntheses of α-eudesmol (5) and cryptomeridiol (6), natural products featuring anti-Alzheimer and anti-spasmodic properties. Compounds 5 and 6 were obtained in three steps in overall yields of 70% and 52%, respectively. 相似文献
11.
《Tetrahedron letters》1987,28(38):4423-4426
The reaction of elemental selenium with sulfur ylides stabilized by electron-withdrawing substituent(s) affords a facile method for generation of functionalized selenocarbonyl compounds, which can be effectively trapped by Diels-Alder reaction with 1,3-dienes. 相似文献
12.
A Trichosanthin gene was cloned from Trichosanthes kirilowii genomic DNA by polymerase chain reaction (PCR). Nucleotide sequence data indicated that we obtained the coding region of the mature Trichosanthin peptide as well as its signal peptide at the N-terminus. Comparisons of our sequence with the previously reported nucleotide sequences of this gene showed 99.25% homology, yet there were notable differences between the previously reported amino acid sequence and our deduced result. This gene was subcloned into a highlevel expression plasmid (pJLA502) of E. coli under the control of a P_RP_L promoter, and we observed the gene product after temperature induction. The gene was further cloned into plant intermediate vector pE3 under the control of a CaMV 35S promoter, and transferred into a tobacco genome using the agrobacterium-mediated gene transfer system. Western blotting analysis of the protein extracted from Escherichia coli and transgenic tobacco plants proved that the Trichosanthin gene has been 相似文献
13.
Zhong Zhou CHENG Ze Hui JIA Yan CHEN Li Ying CHEN Hua LI 《中国化学快报》2006,17(8):1057-1060
Nicorandil [N-(2-hydroxyethyl)-nicotinamide nitrate NIC] is a novel kind of compound in the treatment of angina pectoris. NIC can be degraded easily in storage. The degradation products include N-(2-hydroxyethy) nicotinamide (HN), nitrate ion (NI), and ni… 相似文献
14.
Two dyads of eosin and porphyrin linked with a semi-rigid (-CH2phCH2-) or flexible (-(CH2)4-) bridge and their reference model compounds were synthesized and characterized The intermoleccular interaction and intramolecular photoinduced singlet energy transfer and electron transfer were studied by their absorp tion spectra,fluorescence emission,excitation spectra and fluorescence lifetime The model compounds,ethyl ester of eosm (EoEt) and porphyrin (PorEt),could form complexes in the ground state.When the eosin moieties in dyads were excited,they could transfer some singlet energy to the porphyrins; in the meantime,they could also ndsce electron transfer between two chromophores.Exciting the porphyrin moieties in dyads could induce electron transfer from eosin moieties to porphyrin moieties.The efficiencies (EnT,ET) and rate constants (kEnT,kET) were related to the polarity of solvents and mutual orientation of the two chromophores in dyads. 相似文献
15.
16.
In this paper we will discuss Pauling's classic Eq. (1) that relates bond energies, "D," and electronegativities, "x." Recast to be applicable to enthalpies of formation and reaction, we apply it to the study of hydrogenolysis reactions of dienes, diynes, and alkanes, halogenolysis reactions (with chlorine, bromine, and iodine) and metathetical reactions of organosulfur species (sulfides, sulfoxides, and sulfones). It is with great regret that this equation is found wanting. 相似文献
17.
High molecular weight copoly(ether ketone)s (PEK) based on 4-(4-hydroxyphenyl)-1-phthalazinone (DHPZ)/4,4′-thiobisphenol (TBP)/4,4′-diflourodiphenylketone (DFK) were prepared by nucleophilic substitution polycondensation. The copolymers were characterized by FT- and ^1H-NMR. Thermal properties and solubility of copolymers were studied. 相似文献
18.
This paper reports the results of our thermochemical/calorimetric determination of the enthalpies of combustion, phase change, and formation of isatin, isatoic anhydride, and N-methylisatin. The density functional calculations accompanied by vibrational and thermal corrections were also performed for these compounds and N-methylisatoic anhydride. Through a combination of theoretical calculations and associated isodesmic reactions, we have deduced that isatin has some antiaromatic character and isatoic anhydride enjoys some aromatic stabilization. 相似文献
19.
Isao Yamaguchi Daiki Fukumoto Aohan Wang 《Journal of polymer science. Part A, Polymer chemistry》2021,59(24):3131-3140
π-Conjugated polymers (CPs) and oligomers (COs) bearing hexaphenylbenzene (HPB) and tetraphenyl ethene (TPE) units were synthesized by Sonogashira and Suzuki–Miyaura coupling reactions. The optical properties of the CPs and COs were investigated by UV–vis, photoluminescence (PL), and fluorescence lifetime (τ) measurements. The PL intensities of the solutions of the CPs and COs synthesized by Sonogashira coupling were reduced upon addition of poor solvent like water, which is attributed to aggregation-caused quenching. In contrast, the CP and COs bearing the TPE unit synthesized by Suzuki–Miyaura coupling exhibited aggregation-induced emission enhancement in solution. This difference in fluorescence behavior is discussed herein in terms of the molecular sizes, conformations in solution, and τ values of the CPs and COs. 相似文献
20.
《Polyhedron》1986,5(11):1733-1740
Reaction of protonated 2,2′-bipyridine (bpy) with octacyanometalates(IV and V), [M(CN)8]n− (M = Mo or W, n = 3 or 4), gave the following complexes: {(bpyH)3[M(CN)8]·4H2O}, {(bpyH)3(H3O)[M(CN)8]·H2O}, {(bpyH2)2[W(CN)8]·3H2O} and {(bpyH2)K2[W(CN)8]·2H2SO4·7H2O}. These salts were characterized by electron absorption and reflectance spectrometry, IR, Raman and ESR spectrometry, thermo gravimetry and differential thermal analysis, cyclic voltammetry and potentiometry. The solubility of the salts in water and some polar organic solvents has been measured. The intensively coloured salts of molybdenum(IV) and tungsten(IV) have been discussed in terms of the bpyH+-[M(CN)8]4− ion pairs, which exhibit an outer-sphere electron transfer between adjacent redox sites. 相似文献