title: Synthesis and structure-property relationships of donor/acceptor-functionalized bis(dehydrobenzo[18]annuleno)benzenes.
abstract: Seven new bis(dehydrobenzo[18]annuleno)benzenes (bis[18]DBAs) functionalized with electron-donating dibutylamino groups and/or accepting nitro groups at various positions along the peripheries of the chromophores have been prepared. The effects of varying the donor/acceptor charge transfer pathways, chromophore lengths and molecular symmetries upon the optical band gaps are studied using UV-visible spectroscopy, and structure-property correlations are identified. It is found that bis[18]DBAs possessing donor-pi-donor and acceptor-pi-acceptor pathways exhibit the smallest band gaps, especially when an acceptor-pi-acceptor pathway is situated along the longest chromophore length in the molecule. The all-donor species is also found to exhibit efficient fluorescence with dramatic solvatochromism. The results may have value to the rational design of future NLO/TPA device components.
authors.affiliation: Department of Chemistry and Materials Science Institute, 1253 University of Oregon, Eugene, Oregon 97403-1253, USA.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Spitler
authors.forename: Michael M
authors.initials: MM
authors.lastname: Haley
mesh_terms: D000480:Alkynes / Q000138:chemical synthesis* / Q000737:chemistry; D001555:Benzene Derivatives / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D000480:Alkynes; D001555:Benzene Derivatives; D010165:Palladium