Bond Fixation in a [14]-Annulene: Synthesis, Characterization, and Ab Initio Computations of Furan Adducts of Dimethyldihydropyrene.

Reginald H. Mitchell, Yongsheng Chen, Vivekanantan S. Iyer, Danny Y. K. Lau, Kim K. Baldridge, and Jay S. Siegel

Contribution from the Department of Chemistry, University of Victoria, The San Diego Supercomputer Center, and The University of California, San Diego

Synopsis

Furan adducts of dimethyldihydropyrene are synthesized in order to test the postulate that bicyclic annelations are generally effective at inducing bond localization in aromatic systems. A large 2 ppm down field shift of the NMR shifts of the internal methyl signals in x1 compared to x2 provides a signifiant indicator of bond localization in x1. X-ray diffraction analysis of x3 displays regular bond length alternation. Ab initio computations that do not include dynamics electron correlation are found to be inadequate for modeling the molecular structure of 1. Density Functional Theory models 1 well and predicts bond localization in derivatives of 1 consistent with the observed NMR spectroscopic and X-ray diffraction results.

JACS Manuscript