Dimethyldihydropyrene-dehydrobenzoannulene hybrids: studies in aromaticity and photoisomerization.
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 (1)H and (13)C 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.
Kimball
David B
DB
Department of Chemistry, University of Idaho, P.O. Box 442343, Moscow 83844-2343, USA.
Haley
Michael M
MM
Mitchell
Reginald H
RH
Ward
Timothy R
TR
Bandyopadhyay
Subhajit
S
Williams
Richard Vaughan
RV
Armantrout
John R
JR