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Several strategies are examined and compared for the synthesis of the stable adducts formed by the o-quinone metabolites of carcinogenic polycyclic aromatic hydrocarbons (PAHs) with 2'-deoxyribonucleosides. The copper-mediated method is very useful for the synthesis of [super 13]C- or [super 15]N-labeled analogues and nonformation of bis-adducts as secondary products.

The pyrolysis of methylated polyaromatics with respect to the fate of the main free radicals such as hydrogen, methyl, hydromehtylnaphthyl and methylnaphthyl is studied. The rate constants of these reactions are related to the density of the products.

A series of [3*3] Mn (II)(sub 9), antiferromagneticaly coupled, alkoxided-bridged, square grid complexes, derived from a group of tritopic dihydraizde ligands, is described. With the appropriate coordination information encoded into the ligand itself, self-assembly was shown to be successful in generating novel polynuclear assemblies with ordered, and to some extent predictable, arrays of metal ions in close proximity.

The surfactant-encapsulated europium-substituted heteropolyoxotungatate, (DODA) 11H2[Eu (SiW11O39) 2(H2O) 4] (SEC-2), is structurally described and its photophysical behaviors are studied. Although the electronic properties of SEC-2 originate from polyoxometalates (POM)-2a, the cationic surfactant plays an important role in modifying its photophysical behaviors.

The binding behavior between a rigid, pi-accepting aromatic polycycle (ADIQ.2PF6) and an electron-donating crown ether (CE (10)) is reported in acetonitrile solution. Subsequent charge recombinations are seen to occur with a lifetime of ca. 25 ps and results in greatly enhanced population of the triplet excited state localized on the polycycle.

The cyclization/polymerization strategy provides a route for the construction of electroactive and emissive aromatic structures as shown by the synthesis of a variety of thiophene-based polycyclics from the pendant aromatics. The preparation of a series of arylene-ethynylene polymers with varying degrees of chromophore aromatization is presented.

Research describes the synthesis of polyheterocyclic compounds based on intramolecular Diels-Alder reactions. Results show that the synthetic routes are applicable to a number of tricyclic and tetracyclic condensed pyridines and the skeletal compounds involved in the main reaction.

The plasticity of the coordination sphere of copper(II) lends itself convenient to test the influence of other ligands on the coordination modes of heterobimetallic complexes. Research describes the syntheses, crystal structures, and variable-temperature magnetic properties of three new heterobimetallic rhenium(IV)-copper(II) complexes.

A simple and efficient synthetic route for the synthesis of fused polycyclic ring systems of pyrrolo- and indoloisoquinolinones by intramolecular cyclization reactions is presented. The polycyclic quinolinones are components of natural products and also are biologically active.

Methyl group-induced helicity was studied in 1,4-dimethylbenzo(c)phenanthrene and its metabolites.

Research outlines a new three step methodlology for the syntheisis of Buckybowls. Results describe the steps involved in the preparation of 1,7-dioxal[7](2,7)pyrenophane and 1-8-dioxa[8](2,7)pyrenophane from the corresponding cyclophanedienes. Data suggest that it is feasible to introduce severe nonplanarity to the normally planar pyrene systems by incorporating a tether between 2 and 7 positions.

The Diels-Alder reaction is applied to the synthesis of the polycyclic compounds starting from a suitably substituted 1,3-diene with dimethyl acetylenedicarboxylate, yielding the B, C, or D ring of terpenoid 1,4-dialdehydes.

Research has been conducted on the polycyclic aromatic hydrocarbon (PAH)-utilizing bacteria. The isolation of these bacteria from PAH-contaminated soil is discussed.

A new study investigates the electronic properties of ultrathin films of hexa-peri-hexabenzocoronene columnar molecular stacks.

A new study uses infrared kinetic spectroscopy to investigate the reaction between nitric oxide and the propargyl radical (C3H3).

It has been possible to use powder techniques to obtain the NMR data on the large polycyclic aromatic hydrocarbons coronene and corannulene. Theoretical calculations of the shielding tensor for coronene, corannulene and circumcoronene are also presented.

A new study uses diffuse reflectance laser flash photolysis to investigate the kinetics of germinate ion-electron recombination for several anthracene derivatives and amines on silica gel.

A scaled highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gap is proposed as an index of kinetic stability for a range of polycyclic aromatic or benzenoid hydrocarbon (PAH).

Research was conducted to show how the conformation in solution of 1,1'-binaphthyl derivatives substituted at 2 and 2' with nonauxochromic groups can be evaluated by a spectral parameter, namely the splitting change in maximum wavelength (Delta-lambda max) of the CD exciton couplet. The theoretical relation between Delta-lambda max and the dihedral angle theta, computed starting from the standard hypotheses of exciton model of optical activity of dimers, has indeed been shown to fit quite well the experimental values for a number of such derivatives.

Non-pyrolytic techniques using bromomethyl/dibromomethyl and dibromomethyl/dibromomethyl coupling with low-valent titanium or vanadium were used to synthesize fullerene fragments or buckybowls, specifically, corannulene, cyclopentacorannulene, and a C30H12 semibuckminsterfullerene in significant yields. The study aimed to produce these polynuclear aromatic hydrocarbons to thoroughly analyze their chemistry and their potential use as synthetic intermediates for the total synthesis of fullerenes and as end caps for carbon nanotubes.

Research was conducted to examine the interconversions of norbornadiene using multireference ab initio methods and density functional theory with a 6-31G* basis set. The interconversions include the (1,5)carbon shift in norcaradiene, the formation of norcaradiene from cycloheptatriene, the ring flip of cycloheptatriene and the (1,5)hydrogen shift in cycloheptatriene. Results suggest that the transition state for the formation of toluene from norcaradiene proceeds through a hydrogen transfer transition state that is formed from the allowed transition state of the walk rearrangement but not from the forbidden transition state.

Research was conducted to examine the preparation of a novel family of metal sandwich complexes of silver obtained from silver(I) perchlorate and fluoranthene, benzo(ghi)perylene, (2,2)paracyclophane and decacyclene. Polycyclic aromatic compounds were utilized as an alternative mechanism in the development of organometallic sandwich systems to integrate the coordinative diversity and planarity of the hydrocarbons and the plasticity of the metal ion. Results suggest that the polycyclic aromatic compounds may pave the way to a diverse and rich chemistry in the multilayered metal sandwich systems.

A new class of metabolites, bis-cis-dihydrodiols, is formed during the bacterial biodegradation of carcinogenic polyaromatic hydrocarbons. This is borne out by the biphenyl dioxygenase-catalyzed asymmetric mono-cis-dihydroxylation of the tetracyclic arenes chrysene, benzo(c)phenanthridine and benzo(b)naphtho(2,1-d)thiophene exclusively at the bay or pseudo-bay region using the bacterium Sphingomonas yanoikuyae B8/36. These results indicate a preference of biphenyl dioxygenase for the cis-di- and tetra-hydroxylations of polycyclic arenes at the more hindered bay or pseudo-bay regions by exclusive addition from the same (si:si) face.

Research was conducted to examine the synthesis of calix(4)arenes with four different 'lower rim' substituents. A general synthetic strategy using six-step sequences, wherein monoalkoxycalix(4)arenes were treated with different alkyl halides, was used. The approach is in contrast to previous techniques using either a multistep process or a one-step procedure employing a careful separation method.

A four-step process for the preparation of enantiomerically pure 3,5-diarylpyrrolizidines has been developed resulting in overall yields in the range of 41% to 56%. The new process was based on a double nucleophilic displacement that occurs in chiral 1,7-diaryl-4-[(N-benzyl)amino]heptane-1,7-diols at the conversion of the two hydroxy groups into mesylates. The methodology is of great interest because of the important biological attributes displayed by pyrrolizidine alkaloids.

An easier process of synthesizing unnatural C-5 coumarin glycosyl compounds using sugar beta-keto esters has been developed. The three-step process is composed of Knoevenagel condensation and lactonization, the hydride reduction of the ketone and the acid-mediated acetal exchange. Further conversion to O-/C-glycosides, C-nucleosides, and disaccharides is possible with the use of the free anomeric position in the resulting compound.

Three new types of benzodiazepine alkaloids have been identified from a culture of Aspergillus ochraceus. The new benzodiazepines, a class of alkaloids from which a number of widely used psychoactive drugs have been synthesized and tested, have been labeled as Circumdatin A, B and C. Other benzodiazepines that have been produced from cultures of Aspergillus include aszonalenin, benzodiazepinedione and asperlicins that are used in treating CNS and gastrointestinal problems.

The thermally-induced isomerization of benzoenyne-allenes leads to the formation of two stable triarylmethyl radical centers. The resulting reaction is preceded by the formation of biradicals and is followed by the intramolecular trapping of a tetraarylallene. The experiment has also determined that the five-membered ring present in the fluorene system is essential in leading the reaction into the Myers cycloaromatization pathway.

The tandem [4 + 2] cycloaddition/pyrolytic sulfoxide elimination was developed as a general one pot synthetic process for enantiomerically enriched polycyclic dihydroquinones. Findings revealed a strong ability of the sulfoxide to regulate the regiochemistry and pi-facial diastereoselectivity of the process, being the quinone moiety responsible for the complete endo selectivity attained. The process can be used for the synthesis of optically active helicenebisquinones, provided that vinylarenes react diastereoseletively with homochiral (SS)-(2-p-tolylsulfinyl)-1,4-benzoquinone.

Conjugate addition-rearrangement of hydrazine to alpha,beta-unsaturated sugar delta-lactones was found to provide a short and efficient synthesis of bicyclic pyrazolidinones and beta-D-amino acid derivatives such as (2R,4S)-4-hydroxyhomoproline, (2S,3S,4r)-3,4-dihydroxyhomoproline and (2S,3R,4R)-3,4-dihydroxyhomoproline. The process started with the addition of hydrazine to the lactones resulting in bicyclic pyrazolidinones.

A study was conducted to analyze a two-step preparation of the compound, hexabenzotriphenylene, from commercial starting materials and its characterization as a highly twisted, D3-symmetric molecular propeller by X-ray crystallography. The Spartan program was utilized to perform semiempirical molecular orbital computations. Results indicated reasonable accurate geometries and relative conformational energies for the compounds.

Research was conducted to examine the synthesis of the bay region diketone 2,3:10,11-dibenzoperylene-1,12-dione. The dianion was synthesized in two steps from 9-bromophenanthrene. The chemical shift difference observed for the C6 and C1 carbons and protons provide evidence for the high charge localization at only one bay region of the dianion. Results suggest that an unusual charge 'Umpolung' observed to exist upon reduction of a polycyclic aromatic hydrocarbon system is essential for the synthesis of bay region quinones.

The kinetics of the reactions of benzhydryl cations with heteroarenes (N-methylpyride, furan, 2-methyfuran, and 2-methylthiophene) were obtained photometrically in dichloromethane. The reaction products were characterized in a comprehensive manner by 1H and 13C nuclear magnetic resonance spectroscopy. The reactions followed second-order kinetics with rate-limiting formation of the sigma-adducts.

A general process for the production of 1,2-bridged calix[4]arene monocrowns and biscrowns in the 1,2-alternate conformation was developed. The different factors affecting the conformational result in the reaction of 1,2-functionalized calix[4]arenes with glycol ditosylates and (super t)BuOK in toluene were also examined. This procedure is being used to design new enlarged hydrophobic cavities, based on 1,2-alternate calix[4]arene substructures, which may be useful for the selective inclusion of organic guests.

A new group of molecules based on 6b,10b-dihydrobenzo[j]cyclobut[a]acenaphthalene (DBCA) were synthesized and characterized. These molecules have a possible applications in electronics and optics. The compounds have one or two DBCA units connected through a double bond to an aromatic system. The synthesis of these compounds was conducted mainly through Heck and/or Wittig reactions. The proper compounds can be employed as monomers for photochemically or thermally induced polymerization.

A one-pot process, which combines the Ritter and Friedel-Crafts reactions, was found to provide the first members of a new kind of calix[4]arene-based receptors. The cavity in these receptors was constructed by a calix[4]arene framework fixed in the cone formation and bulky adamantyl and/or phenylacetylene moieties. Amido and amino groups were utilized as possible hydrogen bond donors. Preliminary investigations showed interesting complexation characteristics, specifically, the tetrahedral recognition of water molecules performed by one of the receptors.

A study proposes a very simple and straightforward criterion for distinguishing between aromatic and anti-aromatic compounds that can be used without applying complicated calculations. The criterion is based on valence bond structures which are based on the tendency of electrons to pair in chemical bonds. It will be shown, in particular, that all properties of anti-aromatic compounds can be accounted for using a model based on the premise that the symmetric form of these 4n pi electron cyclic compounds can be represented by an out-of-phase combination of two Kekule-type valence bond structures.

A study was conducted to analyze te preparation of oligomers supporting 1,3-(distal)calix(4)arenes connected to 1,2-vinylene and p-phenylene units by a single carbon-carbon bond at the upper rim of the macrocycle. The receptor characteristics toward silver ions of the oligmer, 1,2-bis(calix(4)arene) ethylene and calix(4)arene O-tetrapropyl ether were then examined. Furthermore, all moisture-sensitive reactions were carried out under a nitrogen environment.

A theoretical study was conducted to analyze the energy spectra of three categories of polybenzenoid hydrocarbons supporting a large number of carbon atoms. The existence of defect states of hydrocarbons with vacancies was also examined. An extended Schrieffer-Heeger model was utilized to determine the geometry of the infinite polymers. Results indicated that point defects resulting from the removal of one or more C atoms from the hydrocarbons generated levels in the energy gap.

A study was conducted to test whether polycyclic aromatic hydrocarbon (PAH)-degrading bacteria like the Cycloclasticus spp in Puget Sound occur in the Gulf of Mexico. Sediment samples were obtained from the nearshore and offshore sites of Puget Sound and the Gulf of Mexico. Results showed that the genus Cycloclasticus can be found in the two geographic locales and is cosmopolitan in nature. Findings also showed that Cycloclasticus strains supported broad PAH substrate values.

The selective isolation of PAHs from complex environmental mixtures was accomplished by means of a new methodology based on antigen-antibody interactions. This method consists on the extraction of PAHs from water samples onto an anti-fluorene immunosorbent (IS) followed by liquid chromatography with diode army detection. Environmental sediments and a sludge reference material containing PAHs were analyzed using this methodology in order to validate the performance of the IS for the cleanup procedure of such materials. Sediments were extracted by sonication with dichloromethane/methanol (2:1), and the extracts were brought to a volume of 100 mL of water in order to perform the extraction with the anti-fluorene IS. The reliability of the cleanup achieved by the IS was well demonstrated in the analysis of sediment and sludge complex samples containing the priority PAHs established by the U.S. EPA at concentrations varying from 56 [[micro]gram]/kg to 26 mg/kg. Results were compared to those obtained with conventional cleanup procedures showing a better selectivity for PAHs. The chromatograms presented a clear baseline allowing the determination and quantification of PAHs at the ppb level. Using immunosorbents, extraction, trace enrichment, and cleanup were accomplished in only one step.

Calculations of the polarizabilities and hyperpolarizabilities of donor-substituted triphenylmethane dyes which are octupolar molecules are undertaken. The nonlinear optical properties of these molecules are described using the four-state model of an octupolar molecule. A strong donor increases the charge-transfer character of the ground state and also increases the molecular polarizability and first hyperpolarizability of the octupolar molecule.

Research was conducted to examine the proton chemical shifts and nucleus-independent chemical shifts (NICS) of the (N)phenylenes and related compounds by the GIAO/HF method. Both NICS and proton chemical shifts values demonstrate attenuation of aromatic and antiaromatic character in the six- and four-membered rings. Both proton and NICS shifts of antikekulene indicate only slight additional antiaromatic property.

The symmetry augmented-chemical shift-chemical shift (SA-CS-CS) correlation spectroscopy used in measuring the chemical shift tensors in polycyclic aromatic compounds was described. Significant intermolecular and intramolecular crystalline effects were observed in the carbon 13 chemical shift tensors. Moreover, the symmetry alterations of an idealized D3h triphenylene molecule allowed the comparison of the tensors from chemical groups with their local symmetry frames.

A validation study to trace the source of an unwanted peak in the gas chromatography electron capture mass spectrometry of polar polycyclic aromatic compounds (PAC) extracted with KO2/O2 showed the unwanted peak to be the ubiquitous presence of polar PACs in the environment. Numerous testing to isolate the source of the unwanted peak failed to isolate the source leading the researchers to conclude that the contaminant PAC is so pervasive in the urban environment as to be difficult to isolate.

Dry deposition flux and aerosol size distribution were measured in Lake Michingan during summer in 1994. A constrained chemical mass balance deposition model proved useful in obtaining physically significant deposition velocities (Vd). Minimum Vd values for particles with physical diameters between 0.09 and 0.53 micronm averaged 0.006 to 0.005 cm s-1 were obtained under stable conditions and mean wind speed of 4.0 m s-1.

An experiment wherein bromine, n-BuLi and o-[(trimethylsilyl)-methyl]benzyl p-tolyl sulfone are used to prepare trimethyl[o-[bromo(p-tolylsulfonyl)methyl]benzyl]silane is presented. In this study, sulfone eliminates trimethylsilyl bromide following a reaction with TBAF in acetonitrile. TBAF further results to dechlorotrimethylsilation of alpha,alpha-diachlorosulfone to chloro(p-tolylsulfonyl)cyclobutene.

Research was conducted to examine the applicability of 13C nuclear magnetic resonance spectroscopy to the biodegradation of hydrocarbon mixtures by using synthetic (1-(super 13)C)acenaphthene. The tracer compound was introduced into creosote polycyclic aromatic compound mixtures degraded by different undefined, mixed and axenic bacterial cultures. Results indicate that the technique may be useful in the evaluation of bioremediation performance.

An experiment is conducted to determine the applicability of fluorescence line narrowing (FLN) spectroscopy to biological matrices without the need for any sample preparation. Results show that, for isopod extracts, FLN can be used to identify the existence of pyreneglucoside in the hepatopancreas. In addition, 1-hydroxypyrene and pyreneglucoside could be identified in the gut and hepatopancreas.

Azaarenes, which are known mutagens and carcinogens, were detected in a number of environmental media in the Liverpool urban atmosphere. The high volume sampling techniques and cascade impactor sampling techniques employed yielded an overall mean azaarene concentration of 2.80 ng m-3. This reveals a very strong seasonal variation that indicates minimum concentration in the summer months and maximum concentration in winter.