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Isocorroles as Homoaromatic NIR-Absorbing Chromophores: A First Quantum Chemical Study.

ABSTRACT: Density functional theory calculations of magnetically induced current densities have revealed high diatropic ring currents in unsubstituted isocorrole consistent with homoaromatic character. An examination of the Kohn-Sham molecular orbitals showed clear evidence of homoconjugative interactions in four occupied ?-type molecular orbitals as well as in the LUMO. Remarkably, substituents at the saturated meso position were found to exert a dramatic influence on the overall current density pattern. Thus, whereas bis(trimethylsilyl)-substitution strongly enhanced the peripheral diatropic current (consistent with enhanced homoaromaticity), difluoro-substitution engendered a strong, net paratropic current (consistent with antihomoaromaticity). In this respect, isocorroles stand in sharp contrast to benzenoid aromatics, for which substituents typically exert a small influence on the current density distribution.

SUBMITTER: Foroutan-Nejad C

PROVIDER: S-EPMC6086901 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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Isocorroles as Homoaromatic NIR-Absorbing Chromophores: A First Quantum Chemical Study.

Foroutan-Nejad Cina C Larsen Simon S Conradie Jeanet J Ghosh Abhik A

Scientific reports 20180810 1

Density functional theory calculations of magnetically induced current densities have revealed high diatropic ring currents in unsubstituted isocorrole consistent with homoaromatic character. An examination of the Kohn-Sham molecular orbitals showed clear evidence of homoconjugative interactions in four occupied π-type molecular orbitals as well as in the LUMO. Remarkably, substituents at the saturated meso position were found to exert a dramatic influence on the overall current density pattern. ...[more]

PMID: 30097587

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