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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

A Computational Study of Tetrafluoro-[2.2]Cyclophanes

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Author(s):
Caramori, Giovanni F. [1] ; Galembeck, Sergio E. [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Pret, BR-14040901 Ribeirao Preto, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Journal of Physical Chemistry A; v. 112, n. 46, p. 11784-11800, NOV 20 2008.
Web of Science Citations: 14
Abstract

A computational study of the isomers of tetrafluorinated {[}2.2]cyclophanes persubstituted in one ring, namely F-4-{[}2.2]paracyclophane (4), F-4-anti-{[}2.2]metacyclophane (5a), F-4-syn-{[}2.2]metacyclophane (5b), and F-4-{[}2.2]metaparacyclophane (6a and 6b), was carried out. The effects of fluorination on the geometries, relative energies, local and global aromaticity, and strain energies of the bridges and rings were investigated. An analysis of the electron density by B3PW91/6-31+G(d,p), B3LYP/6-31+G(d,p), and MP2/6-31+G(d,p) was carried out using the natural bond orbitals (NBO), natural steric analysis (NSA), and atoms in molecules (AIM) methods. The analysis of frontier molecular orbitals (MOs) was also employed. The results indicated that the molecular structure of {[}2.2]paracyclophane is the most affected by the fluorination. Isodesmic reactions showed that the fluorinated rings are more strained than the nonfluorinated ones. The NICS, HOMA, and PDI criteria evidenced that the fluorination affects the aromaticity of both the fluorinated and the nonfluorinated rings. The NBO and NSA analyses gave an indication that the fluorination increases not only the number of through-space interactions but also their magnitude. The AIM analysis suggested that the through-space interactions are restricted to the F-4-{[}2.2]metacyclophanes. In addition, the atomic properties, computed over the atomic basins, shave evidence that not only the substitution, but also the position of the bridges could affect the atomic charges. the first atomic moments, and the atomic volumes. (AU)

FAPESP's process: 02/03753-5 - Computational study of [2.2]cyclophanes
Grantee:Giovanni Finoto Caramori
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)