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71.
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73.
Addition of terpyridine to (TMEDA)Ni(CH3)2 results in the high-yield formation of (terpyridyl)NiMe (3). This NiI organometallic complex was found to be capable of transferring its methyl group to iodocyclohexane to produce methylcyclohexane in high yield. Compound 3 can also serve as an initiator for the catalytic cross-coupling of alkyl electrophiles performed under Negishi-like conditions. 相似文献
74.
Goldsmith JI Hudson WR Lowry MS Anderson TH Bernhard S 《Journal of the American Chemical Society》2005,127(20):7502-7510
The catalytic process of photoinduced hydrogen generation via the reduction of water has been investigated. The use of parallel synthetic techniques has facilitated the synthesis of a 32 member library of heteroleptic iridium complexes that was screened, using high-throughput photophysical techniques, to identify six potential photosensitizers for use in catalytic photoinduced hydrogen production. A Pd/Ni thin film hydrogen selective sensor allowed for rapid quantification of hydrogen produced via illumination of aqueous systems of the photosensitizer, tris(2,2'-dipyridyl)dichlorocobalt ([Co(bpy)(3)]Cl(2)), and triethanolamine (a sacrificial reductant) with ultra-bright light emitting diodes (LEDs). The use of an 8-well parallel photoreactor expedited the investigation of the hydrogen evolution process and facilitated mechanistic studies. All six compounds investigated produced considerably more hydrogen than commonly utilized photosensitizers and had relative quantum efficiencies of hydrogen production up to 37 times greater than that of Ru(bpy)(3)(2+). 相似文献
75.
N. Heldt K. Heldt H. Anderson W. Gaube 《Journal of Thermal Analysis and Calorimetry》1993,40(3):1213-1221
Telomerization of isoprene is characterized by intense thermal effects. The reaction system di-μ-chlorobis(η3-allyl)-dipalladium(II): tri-n-butylphosphine: sodium methylate: isoprene=1∶2∶3∶200 in a solvent-mixture of methanol∶benzene=1∶3 is used as a model. It is concluded that reaction of the catalyst combined with reduction of Pd(II) is followed by the telomerization reaction. There is a marked influence of Pd and phosphine concentration in the catalyst as well as concentration of isoprene. Results are available to optimize technical applications. 相似文献
76.
The disodium alkoxide of 2,6-bis(trifluoromethyl)-2,6-dihydroxy-3,3,4,4,5,5-hexafluorooxane, C(7)F(12)O(3)Na(2), 1, was prepared by reaction of the corresponding diol with MeONa in MeOH. This cyclic alkoxide readily mimics the reaction chemistry of the lithium and sodium alkoxides of perfluoropinacol. The reaction of the alkoxide 1 with covalent dichlorides and metallocene dichlorides yields a series of novel bicyclic ring systems. The crystal structure of the trioxasilane, 3, formed from (CH(3))(2)SiCl(2) was determined to provide structural information about these ring systems. Crystal data: C(9)H(6)O(3)F(12)Si, fw = 418.21 u, orthorhombic space group, Pnma (No. 62), a = 15.822(3) ?, b = 12.163(3) ?, c = 7.373(2) ?, V = 1418.9(4) ?(3), and D(calc) = 1.96 g cm(-)(3) for Z = 4 (molecule possesses mirror symmetry). Least-squares refinement on 1075 observed reflections (I > 3sigma(I)) converged with R = 0.0357 and R(w) = 0.0478. 相似文献
77.
Hsueh SY Muller D Tang J Winston R Zapalac G Swallow EC Berge JP Brenner AE Grafstrom P Jastrzembski E Lach J Marriner J Raja R Smith VJ McCliment E Newsom C Anderson EW Denisov AS Grachev VT Kulikov AV Schegelsky VA Seliverstov DM Smirnov NN Terentyev NK Tkatch II Vorobyov AA Cooper PS Razis P Teig LJ 《Physical review letters》1985,54(22):2399-2402
78.
Frampton MJ Akdas H Cowley AR Rogers JE Slagle JE Fleitz PA Drobizhev M Rebane A Anderson HL 《Organic letters》2005,7(24):5365-5368
[structure: see text] A vinylene-linked porphyrin dimer, with no substituents at the beta-positions, has been synthesized by CuI/CsF promoted Stille coupling. In the crystal structure of this dimer, the C(2)H(2) bridge is twisted by 45 degrees relative to the plane of the porphyrins. The absorption, emission spectra, and electrochemistry reveal substantial porphyrin-porphyrin pi-conjugation. The triplet excited-state absorption spectrum of this dimer makes it suitable for reverse saturable absorption at 710-900 nm. 相似文献
79.
Guldi DM Zilbermann I Anderson G Kotov NA Tagmatarchis N Prato M 《Journal of the American Chemical Society》2004,126(44):14340-14341
Novel organic (positively charged fullerene)-inorganic (negatively charged CdTe nanoparticle) nanoensembles were devised through electrostatic interactions and probed as versatile donor-acceptor hybrids. Photoirradiation of their homogeneous solutions, containing the electrostatically packed components, let to very long-lived (1.3 ms) charge separated states. 相似文献
80.
H.A. Anderson A. Hepburn J.D. Miller M. Stewart R.C. Ferrier T.A.B. Walker 《Analytica chimica acta》1990
Humic substances were isolated from the vegetation throughfall, soil drainage waters and adjacent stream waters at two forested sites in the Central Region of Scotland. Fractionation on XAD-8 hydrophobic resin gave three humic substance components and one hydrophilic acid fraction. Norway spruce generally gave 2–3 times more dissolved organic carbon in the litter drainage compared with Sitka spruce, although there was little qualitative difference in organic acidity between the two litterflows. The humic substances in the drainage at ca. 1 m depth (BC horizon) showed considerable differences between sites, reflecting the types of soils and sources of soil water. Phenolic acids released on hydrolysis confirm the differences between sites and may indicate the sources of subsoil water and their relationships with the stream outputs. 相似文献