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The manganese(III) acetate-mediated free radical cyclization of diarylmethylenecyclopropa[b]naphthalenes with nucleophiles such as carboxylic acid and sulfonic acid provides an efficient method for the synthesis of 1,2-benzanthracenes in moderate to good yields under mild conditions. In addition, after several steps of simple and routine operations, the obtained 1,2-benzanthracenes bearing an acetoxy group could be easily converted to structurally more sophisticated 1,2-benzanthracene derivatives, which are not easily accessible yet potentially useful candidates for materials science.

The reductive reactivity of the cyclooctatetraenide ligands in [(η5-C5Me5)(η8-C8H8)U]2(μ-η3:η3-C8H8), 1, was examined with polycyclic hydrocarbons, phenazine, and the diphenyldichalcogenide compounds PhEEPh (E = S, Se, Te). Complex 1 does not reduce anthracene, acenaphthylene, or benzanthracene, but it acts as a two-electron reductant with phenazine to form 1 equiv of C8H8 and the bimetallic complex [(η5-C5Me5)(η8-C8H8)U]2(μ-η1:η1-C12H8N2), 2. X-ray crystallography showed that the heteroleptic metallocene unit [(C5Me5)(C8H8)U]1+ adopted an η1-coordination mode with the phenazine dianion rather than the η3-coordination previously found with the homoleptic f element metallocene cations [(C5Me5)2M]1+. Complex 1 also reacts as a two-electron reductant with PhEEPh (E = S, Se, Te) to form C8H8 and the heteroleptic complexes [(η5-C5Me5)(η8-C8H8)U]2(μ-EPh)2 (E = S, 3; Se, 4; Te, 5).

The capabilities of AM1 and MNDO methods for the determination of ground-state geometries and vertical excitation energies of perylene, phenanthrene, 1,2-benzanthracene, and 18 of their planar and nonplanar methyl-substituted derivatives has been investigated. It was found that the MNDO method is not suitable for the sterically strained PAH molecules investigated here. The AM1 calculation of the vertical excitation energies was performed using a CI treatment with 225 singly excited configurations. For the spectral shifts of the S{sub 1} excitation energies induced by methyl substitution, a good correlation between calculated and experimental values was obtained. The deformation-induced spectral shift of the twisted 1-methylperylene was correctly obtained as hypsochromic shift but was calculated too small. The potential energy curves for the twisting motion of the naphthalene moieties in the perylene ground and excited states were evaluated and a vibrational analysis of the low-frequency modes was performed. 44 refs., 7 figs., 3 tabs.

Effective diffusivities of polyaromatic solutes in aliphatic solvents were determined from adsorption measurements at ambient conditions with three hydrotreating catalysts of pore diameters 6.2-17.5 nm. Solutes studied were dislike (coronene, 9-phenylcarbazole, tetraphenylporphyrin, and tetra(4-biphenylyl) and rodlike (naphthalene, anthracene, benzanthracene, and dibenz- anthracene) polyaromatics of critical dimensions ranging from 0.74 to 2.18 nm. A modified Wilke-Chang-type correlation was developed to predict bulk diffusivities of the polyaromatic solutes in aliphatic solvents

Carbon-14-labeled benz(a)anthracene was introduced into a large-scale marine microcosm containing as ecosystem typical of the shallow coastal waters of the northeastern U.S. The removal of benz(a)anthracene and metabolites from the water column, their appearance and mixing into the sediments, and the production of carbon dioxide were traced. At the end of the experimental period, 29% of the hydrocarbon has been respired to CO/sub 2/, while the remaining extractable activity (43%) was evenly divided between parent compound and intermediate metabolic products. (3 diagrams, 3 graphs, 37 references, 3 tables)

The four possible isomers of benz(a)anthracene containing a cyclopenta-fused ring have been synthesized and characterized. These systems are of interest for structure-activity studies in bioactivation because of their predicted high level of activity. Formation of fused five-membered rings by intramolecular cyclodehydration, often difficult to accomplish, was found to be smoothly effected in anhydrous hydrofluoric acid (HF), provided the reactivity index (N/sub t/a) for the appropriate electrophilic addition was favorable. The dihydro polycyclic aromatic alcohols obtained from reduction of the corresponding keto cyclodehydration products were best dehydrated to the desired polycyclic aromatic hydrocarbons (PAH) by activity grade I neutral alumina in refluxing benzene. This dehydration proceeds in high yield without the formation of isomeric or polymeric side products that occurred even under such mild acid catalysis as p-toluenesulfonic acid.

Carbon-14-labeled benz(a)anthracene was introduced into an enclosed marine ecosystem that had planktonic primary production and a heterotrophic benthos. Benz(a)anthracene, labeled CO/sub 2/, and operationally defined fractions of labeled degradation products were followed in water and sediments for 202 days. The major fraction of intermediate degradation products was sufficiently water soluble so as not to be readily extractable with organic solvents and at the end was still slowly decaying to CO/sub 2/. Both the parent benz(a)anthracene and degradation products found in the sediment appear to become protected from further alteration after about 2 months and may persist indefinitely. 41 references, 4 figures.

The sorption of pyrene, 3-methylcholanthrene, 7,12-dimethylbenz(a)anthracene, and dibenzanthracene on 14 soil and sediment samples exhibiting a wide range of physicochemical properties was studied. The equilibrium Freundlich constants and linear partition coefficients for each compound were highly correlated with the organic carbon content of the soils/sediments tested. No other significant correlations with soil/sediment properties were observed. The sorption constants when normalized to organic carbon content of the substrate predicted the octanol-water partition coefficients for the compounds tested. A highly significant negative correlation was observed between log substrate and log water solubility for these compounds. Experimental values of the water solubility and octanol-water partition coefficients for the four compounds are reported.

An on-stream, standards addition spectofluorimetric technique has been used to determine the concentrations of anthracene, benz(a)anthracene and benz(a)pyrene in the effluents of generator columns (which yield saturated solutions) at temperatures between 10 and 30/sup 0/C. Concentration values for the standard solutions of PAH's in water over this temperature range were as follows: anthracene, 9.9 x 10/sup -8/ to 34.4 x 10/sup -8/ mol/L; benz(a)anthracene, 1.5 x 10/sup -8/ to 5.7 x 10/sup -8/ mol/L; and benzo(a)pyrene, 2.4 x 10/sup -9/ to 8.9 x 10/sup -9/ mol/L. Confidence limits (99% Working-Hotelling) for the values at 25/sup 0/C were approximately 3-8% of the concentration. The method provides data that agree well with data from dynamic coupled column high-performance liquid chromatography and, together with these values, were used to certify the effluent PAH concentrations of the Standard Reference Material generator columns. The method can be used to determine PAH concentrations in aqueous effluents, aqueous solubilities, and octanol-water partition coefficients in a fast, easy procedure. 5 figures, 5 tables.