Document Detail


Two States Are Not Enough: Quantitative Evaluation of the Valence-Bond Intramolecular Charge-Transfer Model and Its Use in Predicting Bond Length Alternation Effects.
MedLine Citation:
PMID:  25338915     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
The structural weights of the canonical resonance contributors used in the Two-state valence-bond charge-transfer model, neutral (N, R1) and ionic (VB-CT, R2), to the ground states and excited states of a series of linear dipolar intramolecular charge-transfer chromophores containing a buta-1,3-dien-1,4-diyl bridge have been computed by using the block-localized wavefunction (BLW) method at the B3LYP/6-311+G(d) level to provide the first quantitative assessment of this simple model. Ground- and excited-state analysis reveals surprisingly low ground-state structural weights for the VB-CT resonance form using either this Two-state model or an expanded Ten-state model. The VB-CT state is found to be more prominent in the excited state. Individual resonance forms were structurally optimized to understand the origins of the bond length alternation (BLA) of the bridging unit. Using a Wheland energy-based weighting scheme, the weighted average of the optimized bond lengths with the Two-state model was unable to reproduce the BLA features with values 0.04 to 0.02 Å too large compared to the fully delocalized (FD) structure (BLW: ca. -0.13 to -0.07 Å, FD: ca. -0.09 to -0.05 Å). Instead, an expanded Ten-state model fit the BLA values of the FD structure to within only 0.001 Å of FD.
Authors:
Peter D Jarowski; Yirong Mo
Related Documents :
22969475 - (cyanato-κn){1-[(e)-phen-yl(pyridin-2-yl-κn)methyl-idene]semicarbazidato-κ(2)n(1),o}cop...
22595295 - Level anti-crossings in parahydrogen induced polarization experiments with cs-symmetric...
22273875 - Synthesis and conformational studies of peptido-squaramide foldable modules: a new clas...
22318935 - The radiative decay rates tune the emissive properties of ruthenium(ii) polypyridyl com...
19228585 - A fast selenium derivatization strategy for crystallization and phasing of rna structures.
17598275 - Metal complexes and free radical toxins produced by pfiesteria piscicida.
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2014-10-22
Journal Detail:
Title:  Chemistry (Weinheim an der Bergstrasse, Germany)     Volume:  -     ISSN:  1521-3765     ISO Abbreviation:  Chemistry     Publication Date:  2014 Oct 
Date Detail:
Created Date:  2014-10-23     Completed Date:  -     Revised Date:  2014-10-24    
Medline Journal Info:
Nlm Unique ID:  9513783     Medline TA:  Chemistry     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Comment on "The dependence of homogeneous nucleation rate on supersaturation" [J. Chem. Phys. 141, 0...
Next Document:  Prevalence and predictors of coronary artery disease in adults with Kawasaki disease.