Planar Antiaromatic Core-Modified 24π Hexaphyrin(1.0.1.0.1.0) and 32π Octaphyrin(1.0.1.0.1.0.1.0) Bearing Alternate Hybrid Diheterole Units.
Jayaprakash AjaySriram ShirishaMasatoshi IshidaKosuke ItoShigeki MoriHiroyuki FurutaSabapathi GokulnathPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2019)
The Lewis acid catalyzed self-condensation of hybrid diheterole (furan-pyrrole and thiophene-pyrrole) precursors has afforded novel Hückel antiaromatic 24π hexaphyrin(1.0.1.0.1.0) and 32π octaphyrin(1.0.1.0.1.0.1.0) structures without β-annulated bridges. Single-crystal X-ray diffraction analysis of the hybrid porphyrinoids (S3 N3 -ox and O4 N4 -ox) revealed a nearly planar conformation and the 1 H NMR spectra suggest the presence of paratropic ring currents. These antiaromatic macrocycles show characteristic optical features and underwent reversible two-electron reduction to Hückel aromatic 26π- and 34π-electron species, respectively, as is evident from the results of spectroscopic and theoretical studies (nucleus-independent chemical shift (NICS) and anisotropy of the current-induced density (ACID) calculations). The incorporation of hybrid diheteroles alternately into expanded porphyrin skeletons provides a novel approach to the fine-tuning of the electronic structures of planar antiaromatic macrocycles.
Keyphrases
- high resolution
- electron microscopy
- molecular dynamics simulations
- density functional theory
- magnetic resonance
- photodynamic therapy
- molecular docking
- air pollution
- magnetic resonance imaging
- solid state
- crystal structure
- drug induced
- diabetic rats
- oxidative stress
- amino acid
- high speed
- endothelial cells
- stress induced
- energy transfer