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Calculations of binding energies and optimum geometries of compounds of the series M(H2O)+ with M = Sc to Zn have been carried out and compared with gas-phase experimental data and with the Rosi and Bauschlicher MCPF calculations. Hartree–Fock calculations and correlated calculations at MP2, MP4, and QCISD(T) levels were used to test the dependence of the results upon the level of correlation. A test of basis set dependence was also carried out, using parallel calculations on four basis sets ranging in size from a small DZ set to a TZ contraction. Correlation levels above MP2 and elaboration of the metal d-function basis set to (4d/3d) size or greater were both necessary for convergence with the most uniformly reliable results obtained from QCISD(T) calculations on a basis set with a (6d/4d) contraction for the d-function space. However, MP2 or higher-level calculations with a contracted four or five d function set [(5d/3d) or (4d/3d)] are capable of yielding results on binding energies and geometries close to the current gas-phase experimental uncertainty on electrostatically bound transition metal complexes. © 1993 John Wiley & Sons, Inc. 相似文献
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Mohammad A. Hai Nigel W. Preston Rolf Kyburz Emanuel Schpp I. Ralph C. Bick Manfred Hesse 《Helvetica chimica acta》1980,63(7):2130-2134
Aristoserratine, a New Indole Alkaloid from Aristotelia serrata W.R.B. OLIVER and from A. peduncularis (LABILL .) HOOK . F. The new indole alkaloid aristoserratine (2) has been isolated from Aristotelia. Its structure and absolute configuration were elucidated on the basis of spectroscopic data. 相似文献
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Hans-Peter Ros Rolf Kyburz Nigel W. Preston Rex T. Gallagher I. Ralph C. Bick Manfred Hesse 《Helvetica chimica acta》1979,62(2):481-487
The revised structure 1 is put forward for peduncularine, the main alkaloid of Aristotelia peduncularis (Labill.) HOOK. F. (Elaeocarpaceae), on the basis of its spectroscopic properties and those of its degradation products, the Hofmann base 3 and the hydrogenation product 4 . Structure 1 represents the relative configuration of the alkaloid. Peduncularine belongs to the class of indole alkaloids with a monoterpene unit as the aliphatic portion. To our knowledge it constitutes the first example in which an isopropyl group has become detached from the terpene unit and occurs as a substituent on nitrogen. 相似文献
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Nigel M. Groome Elghareeb E. Elboray Dr. Martyn W. Inman Prof. H. Ali Dondas Dr. Roger M. Phillips Colin Kilner Prof. Ronald Grigg 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(6):2180-2184
Naturally occurring indole‐3‐carbinol and 3,3‐diindolylmethane show bioactivity in a number of disparate disease areas, including cancer, prompting substantial synthetic analogue activity. We describe a new approach to highly functionalised derivatives that starts from allene gas and proceeds via the combination of a three‐component Pd0‐catalysed cascade with a one‐pot, three‐component carbophilic PtII cascade linked to a stereoselective acid‐catalysed Mannich–Michael reaction that generates complex cyclopropyl diindolylmethanes which show selective activity against prostate cancer cell lines. 相似文献
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Nathan Barker Nigel Boston Norbert Peyerimhoff Alina Vdovina 《Monatshefte für Mathematik》2012,3(2):319-327
We find new mixed and unmixed Beauville structures for groups constructed as 2-quotients, i.e. quotients of 2-power order, of the fundamental group of a certain simplicial complex. 相似文献
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