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31.
Joanne E. Stanley Anthony C. Swain Kieran C. Molloy David W. H. Rankin Heather E. Robertson Blair F. Johnston 《应用有机金属化学》2005,19(5):644-657
Perfluoroalkytin compounds R(4−n)Sn(Rf)n (R = Me, Et, Bu, Rf = C4F9, n = 1; R = Bu, Rf = C4F9, n = 2, 3; R = Bu, Rf = C6F13, n = 1) have been synthesized, characterized by 1H, 13C, 19F and 119Sn NMR, and evaluated as precursors for the atmospheric pressure chemical vapour deposition of fluorine‐doped SnO2 thin films. All precursors were sufficiently volatile in the range 84–136 °C and glass substrate temperatures of ca 550 °C to yield high‐quality films with ca 0.79–2.02% fluorine incorporation, save for Bu3SnC6F13, which incorporated <0.05% fluorine. Films were characterized by X‐ray diffraction, scanning electron microscopy, thickness, haze, emissivity, and sheet resistance. The fastest growth rates and highest quality films were obtained from Et3SnC4F9. An electron diffraction study of Me3SnC4F9 revealed four conformations, of which only the two of lowest abundance showed close F Sn contacts that could plausibly be associated with halogen transfer to tin, and in each case it was fluorine attached to either the γ‐ or δ‐carbon atoms of the Rf chain. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
32.
Heredia KL Tao L Grover GN Maynard HD 《Journal of polymer science. Part A, Polymer chemistry》2010,1(2):168-170
A heterotelechelic biotin-maleimide polymer containing a cleavable disulfide bond was synthesized by RAFT polymerization and used to reversibly modify surfaces with proteins. 相似文献
33.
[formula: see text] The synthesis of 1,3-difluoro-2,4-diphenylbenzene has been accomplished in one step from 1,2-diphenylcyclobutene using the environmentally benign difluorocarbene precursor sodium chlorodifluoroacetate. In addition, the preparation of the previously unknown compound 1,3-difluoro-2,4-di-n-propylbenzene has been accomplished in one step from 1,2-di-n-propylcyclobutene using Seyferth's reagent (Ph-Hg-CF3) and sodium chlorodifluoroacetate. 相似文献
34.
Several dihydrogen complexes of ruthenium of the form [Cp/Cp*Ru(P-P)H(2)](+) (P-P = chelating diphosphine ligand) have been prepared by reaction of the corresponding neutral chloride complexes with H(2) in the presence of NaB(ArF)(4). Treatment with D(2) or T(2) gas leads to incorporation of deuterium or tritium in the dihydrogen ligand. Measurement of the resulting H-D and H-T couplings as a function of the temperature and magnetic field gives results consistent with computational studies which predict that the H-H bond distance will increase with temperature and will be significantly shortened by isotopic substitution. The degree of the observed temperature dependence is found to be a critical function of the ancillary ligand set. 相似文献
35.
Parrondo games are coin flipping games with the surprising property that alternating plays of two losing games can produce a winning game. We show that this phenomenon can be modelled by probabilistic lattice gas automata. Furthermore, motivated by the recent introduction of quantum coin flipping games, we show that quantum lattice gas automata provide an interesting definition for quantum Parrondo games. 相似文献
36.
37.
Johnston BF Mitzel NW Rankin DW Robertson HE Rüdinger C Schmidbaur H 《Dalton transactions (Cambridge, England : 2003)》2005,(13):2292-2299
The structures of 1,3,5-trisilylbenzene and hexasilylbenzene in the gas phase have been determined by electron diffraction, and that of 1,3,5-trisilylbenzene by X-ray crystallography. The structures of three trisilylbenzene isomers, three tetrasilylbenzenes, pentasilylbenzene and hexasilylbenzene have been computed, ab initio and using Density Functional Theory, at levels up to MP2/6-31G*. The primary effect of silyl substituents is to narrow the ring angle at the substituted carbon atoms. Steric interactions between silyl groups on neighbouring carbon atoms lead first to displacement of these groups away from one another, and then to displacement out of the ring plane, with alternate groups moving to opposite sides of the ring. In the extreme example, hexasilylbenzene, the SiCCSi dihedral angle is 17.8(8) degrees . 相似文献
38.
The utility of a Design of Experiments (DoE) approach for the rapid and efficient optimisation of a microwave assisted Ugi 3cc reaction of levulinic acid is demonstrated. DoE methods have also been applied to the assessment of the reaction scope for a range of amine and isonitrile substrates. The optimal procedure developed using this approach has enabled the preparation of lactam derivatives in moderate to excellent yields (17-90%) in a reaction time of only 30 min compared to the conventional methodology which required up to 48 h. 相似文献
39.
40.
Adams Peter Bryant Darryn El-Zanati Saad I. Gavlas Heather 《Graphs and Combinatorics》2003,19(3):289-296
In this paper, we show that K10n can be factored into C5-factors and 1-factors for all non-negative integers and satisfying 2+=10n–1.Research partially supported by an NSF-AWM Mentoring Travel Grant 相似文献