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Ulf Ryde Mats H. M. Olsson Björn O. Roos Antonio Carlos Borin 《Theoretical chemistry accounts》2001,105(6):452-462
The accuracy of theoretical calculations on models of the blue copper proteins is investigated using density functional theory
(DFT) Becke's three-parameter hybrid method with the Lee–Yang–Parr correlation functional (B3LYP) and medium-sized basis sets.
Increasing the basis set to triple-zeta quality with f-type functions on all heavy atoms and enlarging the model [up to Cu(imidazole-CH3)2(SC2H5) (CH3SC2H5)0/+] has only a limited influence on geometries and relative energies. Comparative calculations with more accurate wave-function–based
methods (second-order M?ller–Plesset perturbation theory, complete-active-space second-order perturbation theory, coupled-cluster
method, including single and double replacement amplitudes and in addition triple replacement perturbatively) and a variety
of basis sets on smaller models indicate that the DFT/B3LYP approach gives reliable results with only a small basis set dependence,
whereas the former methods strongly depend on the size of the basis sets. The effect of performing the geometry optimizations
in a continuum solvent is quite small, except for the flexible Cu-SMet bond. The results of this study confirm the earlier results that neither the oxidized nor the reduced copper site in the
blue proteins is strained to any significant degree (in energy terms) by the protein surrounding.
Received: 7 July 2000 / Accepted: 17 November 2000 / Published online: 21 March 2001 相似文献
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Stephen Fletcher 《Journal of Solid State Electrochemistry》2007,11(7):965-969
We propose a new model for the elementary act of electron transfer between two species in solution. The central idea is that
the solution in the immediate vicinity of each species may be represented by an equivalent circuit consisting of a Debye circuit
shunted by a resistor. Based on this insight, we derive a new formula for the one-dimensional potential energy profile of
a coupled donor–acceptor pair at finite (but large) separation d, along a charge-fluctuation reaction co-ordinate, at fixed radii of the transition states. The corresponding reorganisation
energy of the reaction is also derived, and it is found to differ from that in the Marcus theory. In particular, the new model
predicts that the reorganisation energy is independent of the static dielectric constant of the solution, whereas the old model predicts a strong dependence. The difference is
traced to the fact that the Marcus theory omits consideration of the work required to form the charge fluctuations and focuses
instead on the work required to localise the charge fluctuations. In general, the equivalent circuit approach permits many
of the difficult-to-derive equations of non-equilibrium polarisation theory to be written down by inspection. 相似文献
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Julio Romero‐Ibaez Silvano Cruz‐Gregorio Jacinto Sandoval‐Lira Julio M. Hernndez‐Prez Leticia Quintero Fernando Sartillo‐Piscil 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(26):8959-8963
One of the major challenges in organic synthesis is the activation or deconstructive functionalization of unreactive C(sp3)–C(sp3) bonds, which requires using transition or precious metal catalysts. We present here an alternative: the deconstructive lactamization of piperidines without using transition metal catalysts. To this end, we use 3‐alkoxyamino‐2‐piperidones, which were prepared from piperidines through a dual C(sp3)–H oxidation, as transitory intermediates. Experimental and theoretical studies confirm that this unprecedented lactamization occurs in a tandem manner involving an oxidative deamination of 3‐alkoxyamino‐2‐piperidones to 3‐keto‐2‐piperidones, followed by a regioselective Baeyer–Villiger oxidation to give N‐carboxyanhydride intermediates, which finally undergo a spontaneous and concerted decarboxylative intramolecular translactamization. 相似文献
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