Document Detail

Ab Initio Molecular Orbital Study on the Excited States of [2.2]-, [3.3]-, and Siloxane-Bridged Paracyclophanes.
MedLine Citation:
PMID:  23046357     Owner:  NLM     Status:  Publisher    
Paracyclophanes are simple idealized model molecules for the study of interacting π-stacking systems. In this study, the excited states of [2.2]paracyclophane ([2.2]PCP), [3.3]paracyclophane ([3.3]PCP), and siloxane-bridged paracyclophane (SiPCP) are systematically investigated using the multiconfiguration quasi-degenerated perturbation theory (MCQDPT) method. The excited states of the alkyl- and silyl-substituted benzene monomers and benzene dimer, which can be regarded as the building blocks of paracyclophanes, are also examined at the same level of theory for more detailed understanding. The accuracy of the time-dependent density functional theory (TD-DFT) method required for excited state geometry optimization of the paracyclophanes is confirmed from calculations of the benzene dimer. The equilibrium distances between the benzene rings of the paracyclophanes in the first excited states are shorter than those in the ground state, and the benzene rings at the excited state optimized geometries are in an almost eclipsed parallel configuration, which indicates excimer formation. The calculated transition energies and oscillator strengths are generally in good agreement with the corresponding experimental results. A clear correlation between the excited state properties and the molecular structures is systematically demonstrated based on the calculation results for the substituted benzene monomers and benzene dimer. The transition energies of SiPCP are close to the corresponding absorption and fluorescence energies of the experimentally studied phenylene-silica hybrids, which indicates that the electronic properties of organic-silica hybrids, which is a new class of material with potential in photofunctional applications, can be approximated by simple siloxane-bridged cyclophane derivatives.
Soichi Shirai; Suehiro Iwata; Yoshifumi Maegawa; Takao Tani; Shinji Inagaki
Related Documents :
22992117 - Energy flow in the cryptophyte pe545 antenna is directed by bilin pigment conformation.
24065357 - Absence of strong magnetic fluctuations in fep-based systems lafepo and sr2sco3fep.
25042937 - Switching of single-molecule magnetic properties of tb(iii) -porphyrin double-decker co...
23014147 - Thermoelectric properties of hfn/scn metal/semiconductor superlattices: a first-princip...
11112607 - Generation, characterization, and kinetics of triplet di[1,2,3,4,5,6, 7,8-octahydro-1,4...
21161557 - Structural studies of biologically active glycosylated polyamidoamine (pamam) dendrimers.
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-10-9
Journal Detail:
Title:  The journal of physical chemistry. A     Volume:  -     ISSN:  1520-5215     ISO Abbreviation:  J Phys Chem A     Publication Date:  2012 Oct 
Date Detail:
Created Date:  2012-10-10     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9890903     Medline TA:  J Phys Chem A     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Toyota Central R&D Laboratories, Inc. , Nagakute, Aichi 480-1192, Japan.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

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

Previous Document:  Diabetes mellitus and the incidence and mortality of colorectal cancer: a meta-analysis of 24 cohort...
Next Document:  Differential effects of intranasal vaccination with recombinant NcPDI in different mouse models of N...