English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Critical Role of the Correlation Functional in DFT Descriptions of an Agostic Niobium Complex

Pantazis, D. A., McGrady, J. E., Maseras, F., & Etienne, M. (2007). Critical Role of the Correlation Functional in DFT Descriptions of an Agostic Niobium Complex. Journal of Chemical Theory and Computation, 3(4), 1329-1336. doi:10.1021/ct700043w.

Item is

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Pantazis, Dimitrios A.1, Author           
McGrady, John E.1, Author
Maseras, Feliu2, 3, Author
Etienne, Michel4, Author
Affiliations:
1WestCHEM, Department of Chemistry, University of Glasgow, Glasgow G12 8QQ, U. K., ou_persistent22              
2Institute of Chemical Research of Catalonia (ICIQ), AVgda, Paϊsos Catalans 16, 43007, Tarragona, Spain, ou_persistent22              
3Unitat de Química Física, Edifici Cn, UniVersitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain, ou_persistent22              
4Laboratoire de Chimie de Coordination du CNRS, UPR 8241 liée par conventions à l'Université Paul Sabatier et à l'Institut National Polytechnique de Toulouse, 205 Route de Narbonne, Toulouse Cedex 4, France , ou_persistent22              

Content

show
hide
Free keywords: -
 Abstract: In previous studies of the agostic bonding in TpMe2NbCl(R‘CCR‘ ‘)(R), we have made use of a hybrid QM/MM protocol (B3LYP:UFF) where the QM partition ([Nb(Cl)(iPr)(HCCH)(NHCH2)3]+) was rather small, but the optimized structures were nevertheless in apparently good agreement with experiment. In attempting to improve this model by expanding the size of the QM region, we were surprised to discover that a full QM treatment of the whole molecule using the B3LYP functional failed to locate an agostic structure of any kind. A systematic assessment of density functionals reveals that the poor performance of B3LYP in these systems is typical of all DFT methods that do not obey the uniform electron gas (UEG) correlation limit. Those that do obey the UEG limit, in contrast, provide an excellent description of the agostic structure when the complete ligand system is treated at the QM level. The apparently good performance of our original (B3LYP:UFF) hybrid method can be traced to a cancellation of errors:  the B3LYP functional underestimates the intrinsic strength of the agostic interaction relative to competing Nb−Cl π bonding, but this is offset by an additional but unphysical electrostatic component to the agostic bond introduced by the presence of a positive charge in the QM region.

Details

show
hide
Language(s): eng - English
 Dates: 2007-05-262007-07-01
 Publication Status: Issued
 Pages: 8
 Publishing info: -
 Table of Contents: -
 Rev. Type: Peer
 Identifiers: DOI: 10.1021/ct700043w
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Journal of Chemical Theory and Computation
  Other : J. Chem. Theory Comput.
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Washington, D.C. : American Chemical Society
Pages: - Volume / Issue: 3 (4) Sequence Number: - Start / End Page: 1329 - 1336 Identifier: ISSN: 1549-9618
CoNE: https://pure.mpg.de/cone/journals/resource/111088195283832