Crystal and molecular structures of overcrowded halogenated compounds. VIII. Two overcrowded naphthalenes – octachloronaphthalene and tetrabenznaphthalene (dibenzo[g,p]chrysene)

Tetrachlorophthalic anhydride (TCPA), a refinement

“…This feature is similar to that in the furan ring of phthalic anhydride (Bates & Cutler, 1977), but different from that of a complexed TCPA molecule in naphthalene-TCPA (Wilkerson, Chodak & Strouse, 1975). The average C-C1 bond distance, 1.711 A, is comparable to those of polychloroaromatic compounds in which the substituted CI atoms occupy adjacent ortho positions to each other (Herbstein, 1979;Ito, Moriya, Kashino & Haisa, 1975;Brown & Strydom, 1974;Chu, Jeffrey & Sakurai, 1962). Table 2 shows three least-squares planes about the TCPA molecule with the deviations of atoms from the planes.…”

Dibenzo[a,l]pyrene (dibenzo[def,p]chrysene): fjord-region distortions

“…As seen in Figure 6 torsion angles are in the range 0-4°and angular increases are of the order of 2-3°(giving a maximum sum of Ͻ6°). An exception is the compound with the CSD refcode TEBNAP10 (formula 4) which has two fjord regions and is considerably distorted as a result (20), therefore giving larger torsional distortions (15.8 and 18.9°) in the bay area, b. The steric overcrowding is more serious in fjord regions ('f' in Figure 5 and shown as large filled circles in Figure 6).…”

Crystal and molecular structures of overcrowded halogenated compounds. IX. Stereochemistry of molecules containing the perchlorofluorenyl and perchlorofluorenylidene moieties and of their hydrogen analogues

“…The rich stereochemical information which can be extracted from the results of the crystal structure analyses represents in a sense answers to questions which still have to be posed. Allen, Kennard, Watson, Brammer, Orpen & Taylor (1987) give 1.720(10),~ for the mean value of Car--C1 (o-C12) (364 entries); this should be compared with 1.719 (5) ,~ given by Gall et al (1985) (32 entries) and an earlier value of 1.717 (8)A, (Herbstein, 1979). We obtain 1.718 (4)A, as the mean for the 16 C--CI distances where chlorines are bonded to sp 2 carbons of the cyclohexadiene moieties; this does not differ significantly from the value of 1-711 (11)A given by Allen, Kennard, Watson et al (1987) for CI--C----C--C1 fragments.…”

“…Among the crystal and molecular structures reported are those of 1,4,-5,8-tetrachloronaphthalene (Gafner & Herbstein, 1962), octachloronaphthalene (Gafner & Herbstein, 1963;Herbstein, 1979), decachloropyrene (Hazell, 1978), octabromonaphthalene (Brady, Redhouse & Wakefield, 1982), decachlorophenanthrene (Herbstein, Kapon & Merksamer, 1976), perchlorocoronene (Baird, Gall, MacNicol, Mallinson & Michie, 1988)and 1,10-dichloro-3,8-dimethyl-4,7-phenanthroline (Herbstein, Kapon & Rabinovich, 1972.…”