title: Bay- and fjord-region distortions in dibenz[a,j]anthracene and tetrabenzo[de,hi,mn,qr]naphthacene.
abstract: The crystal structure of 7,14-dimethyldibenz[a,j]anthracene (DMDBA) has been determined, and the crystal structure of tetrabenzo[de,hi,mn,qr]naphthacene (TBNC) has been redetermined at higher precision than previously reported. These molecules are polycyclic aromatic hydrocarbons (PAHs) that have, respectively, two hindered bay regions and two fjord regions; the former PAH is a known carcinogen. The extensive out-of-plane bending as a result of steric overcrowding in the bay and fjord regions in these PAHs is shown by these studies. For DMDBA, the angle between the 14-methyl group and the outer rings is 32.6 degrees. For TBNC, the angle between the outer rings of the molecule is 31.9 degrees. These structures are compared with those of related structures of 7,12-dimethylbenz[a]anthracene and dibenzo[g,p]chrysene. It appears that steric overcrowding in such PAHs can cause distortions of up to 33 degrees C. Such steric overcrowding will affect the conformations of bay- and fjord-region diolepoxides, which are the presumed activated metabolites in the carcinogenic process.
authors.affiliation: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111.
authors.forename: C J
authors.initials: CJ
authors.lastname: Carrell
authors.forename: H L
authors.initials: HL
authors.lastname: Carrell
authors.forename: J P
authors.initials: JP
authors.lastname: Glusker
authors.forename: E
authors.initials: E
authors.lastname: Abu-Shaqara
authors.forename: C
authors.initials: C
authors.lastname: Cortez
authors.forename: R G
authors.initials: RG
authors.lastname: Harvey
mesh_terms: D001551:Benz(a)Anthracenes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005583:Fourier Analysis; D008968:Molecular Conformation; D015394:Molecular Structure; D009279:Naphthacenes / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D001551:Benz(a)Anthracenes; D009279:Naphthacenes; C091195:tetrabenzo(de,hi,mn,qr)naphthacene; C053717:7,14-dimethyldibenz(a,j)anthracene