Dimethyldihydropyrene−Dehydrobenzoannulene Hybrids:  Studies in Aromaticity and Photoisomerization

• Published in: Journal of organic chemistry Vol. 67; no. 25; pp. 8798 - 8811
• Main Authors: Kimball, David B, Haley, Michael M, Mitchell, Reginald H, Ward, Timothy R, Bandyopadhyay, Subhajit, Williams, Richard Vaughan, Armantrout, John R
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 13-12-2002
• Subjects: Chemistry; Condensed benzenic and aromatic compounds; Exact sciences and technology; Organic chemistry; Preparations and properties; Bond length; Aromaticity; Acetylenic compound; Photoisomerization; Benzopyrene derivatives; Pyrene derivatives; NMR spectrometry; Experimental study; Chemical shift; Annulene; Density functional method; Conjugated compound; Chemical synthesis; Ethylenic compound
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo020462q

The synthesis and study of dehydrobenzoannulene (DBA)−dimethyldihydropyrene (DDP) hybrids as models for the investigation of aromaticity in weakly diatropic systems is reported. Three new monofused DBA−DDP hybrids have been synthesized, and their NMR spectra are discussed with regard to quantifying the aromaticity remaining in multibenzene-fused DBAs. Nucleus-independent chemical shifts, determined at a series of locations for each compound, bond lengths, and 1H and 13C NMR chemical shifts were calculated and used to probe the aromaticity of these hybrids. Systems where more than one annulene/DBA is fused to the DDP core have also been obtained, and their potential use in photoinduced isomerization applications is discussed.