ISSN:
0894-3230
Keywords:
Organic Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The molecular structure of [4] metacyclophane is optimized at the ab initio STO-3G SCF level and a genuine minimum is located. In the STO-3G structure the benzene ring is less bent and geometrically distorted than in the previously reported MNDO structure. Although some bond alternation is calculated for the carbon-carbon bond lengths of the bent benzene ring, their values still fall in the range of highly delocalized compounds. Despite the fact that the STO-3G strain energy [SE(tot.)] is larger than the corresponding MNDO strain energy, the distribution of SE(tot.) over the bent benzene ring [SE(bb.)] and the oligomethylene bridge [SE(br.)] is similar. To facilitate the hitherto unsuccesful identification of [4] metacyclophane, its electronic transition energies were calculated with CNDO/S-CI using the STO-3G geometry as input geometry. The reliability of the CNDO/S-CI results was assessed by a comparison of calculated and experimental electronic transition energies for p- and, m-xylene, [5] para- and [5] metacyclophane and [4] paracyclophane following the same approach.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/poc.610060307
Permalink