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A new class of polcyclic aromatic hydrocarbons - oligoindenopyrenes was prepared featuring a Pd-catalyzed Suzuki-Heck coupling cascade. It is observed that after excitation, the tetraindenopyrene derivative 3d undergoes efficient deactivation (99%) by internal conversion to the ground state and the small fluorescence quantum yield (0.004) is in accordance with the short ( 0.6 ns) fluorescence decay time.

The reduction of several annelated corannulene derivatives was undertaken using lithium and potassium metals. It was found that annelation affects the annulenic character of corannulene by changing its charge distribution.

The geometrics, structures and energetics of a series of unusual geodesic polyarenes are described. Symmetry considerations, bond length alternations and NICS value indicate that ground states of dicyclobuta[de,ij]naphthalene, dihydrodicyclobuta[de,ij]naphthalene and dihydrocyclopenta[cd,gh]pentalene are aromatic.

A four-step procedure is reported for the transformation of diaryl ketones into polycyclic aromatic hydrocarbons and heterocycles that contain a newly formed, fused naphthalene ring system. The transition metal-catalyzed double ring closures of 1,1-diaryl-2,2-diethynylethylenes in the final step appear to work best for those compounds in which the distances between the atoms to be joined are less than about 3.35-3.40 angstrom.

The molecular structure of decachlorocorannulene is investigated by gas-phase electron diffraction. The structure is in excellent agreement with the prediction from the B3LYP/6-311G calculation.

A short, practical synthesis of the C(sub 26)H(sub 12) bowl-shaped fullerene fragment diindenochrysene (1) is devised. Flash vacuum pyrolysis of the twisted bifluorenylidene 2, with bromine atoms strategically placed at the sites of the desired closures, give 1 in 25-35% yields. A four-step synthesis has been developed to prepare the pyrolysis precursor (2) as a mixture of (E)- and (Z)-isomers in 39% overall yield from commercially available 9-fluorenone 1-carboxylic acid (10).

The study reports a comprehensive and systematic study of local magnetic properties of charged fullerenes and methylene-bridged fullerenes. The main focus is laid on the magnetic properties of fullerene anions by using the nuclear magnetic resonance spectroscopy.

Aromaticity of cyclopentafused pyrene congeners has been investigated at various levels of theory. Aromaticity of these compounds decreased with increasing number of externally fused five-membered rings.

Research has been conducted on the smallest symmetrical bowl-shaped fragments of C (sub)60 and its tetra-tert-butyl derivative. The reduction of these compounds with lithium metal has been carried out to yield dianions and tetraanions.

Halogen-capped aniline trimers represent an important class of molecules and they are herein investigated by Density functional theory (DFT) calculations. It was found that the halogen-capped aniline trimers are better acceptors than the amino-capped aniline trimers in the base form.

The light-induced ejection of an electron from coranulene dianion is demonstrated and photoproducts by means of time-resolved ERP and laser flash photolysis is characterized. Electrostatic repulsion between corannulene radical anion and the ejected electron facilitates the dissociation of the initially formed cage of the photoproducts.

Research is done on the molecular structure of corannulene which has been examined by gas-phase electron diffraction with help from ab initio calculations at the B3LYP/6--31(d) level and normal coordinate analysis. The average C--C bond is about 0.022 angstrom shorter than in C60 and the structure is analyzed.

Issues concerning the preparation of a geodesic dome, which is 60% of C60, are discussed. The method for developing a circumtrindene with an increased yield has potential for making bigger open geodesic polyarenes and closed fullerenes.

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.

Research was conducted to examine an energy barrier on the order of 60 kcal/mol which is predicted for the 1,2-shifts of hydrogen atoms in aryl radicals. The 2-benzo(c)phenanthryl radical was produced using flash vacuum pyrolysis of the corresponding aryl bromide to demonstrate the rearrangement. The cyclization and rearomatization of the resulting radical followed a 1,2-shift of hydrogen out of the sterically congested cove region of the 2-benzo(c)phenanthryl radical. Computational results indicate that aryl radicals should be good candidates to exhibit 1,2-shift rearrangements of hydrogen atoms.

Corannulene has served as an efficient electron carrier between lithium metal and solid fullerenes, in the reduction of (super3)He@C(sub60) and (super3)He@C(sub70) by lithium metal, giving solutions of the corresponding hexaanions in THF-d(sub8). The (super3)He within the C(sub60) hexaanion was more strongly shielded than previous reports, and results are in complete accord with earlier predictions of the dramatic alteration of the magnetic properties of C(sub60) and C(sub70), by reduction of fullerenes to their hexaanions.

Analysis of methanol adsorption on aluminum (100) surface using small cluster quantum mechanical measurements and the hybrid Hartree-Fock/density functional theory showed that the preferred site for methoxy chemisorption and adsorption enthalpy can be derived. Methanol favored the two-fold bridge site to the four-fold hollow site. Activation energy for the bridge-adsorbed methoxy showed similarity with experimentally determined results.

Modification of a one-step synthesis of 7,10-disubstituted fluoranthene through successive pyrolysis and bromination led to the 7,10-bis(1-chlorovinyl)fluoranthene precursor which enables producing 250-300mg samples of corannulene in a single pyrolysis run. This precursor can be produced just two steps away from commercially available starting materials. Results indicate that the first steps in the conversion of this precursor to corannulene involve thermal loss of two hydrogen chloride molecules to generate diyne 7,10-diethylfluoranthene.

A carbon-13 nuclear magnetic resonance (13C NMR) study shows that the physical transport of metabolites across the mitochondrial membrane of intact heart tissues can detect isotope turnover rate in the glutamate pool. The observed turnover rate indicates metabolic communication between the mitochondria and cytosol due to the physiological state of intact tissues. The process involves the transport of metabolic intermediates through the redox-sensitive malate-aspartate shuttle.

Tetrahydrofuran (THF) solutions of corannulene (Cor) show electron paramagnetic resonance (EPR) that depend on the reduction stage of Cor, the nuclear spin and the temperature. Photoexcitation of THF solutions produces a spin polarized EPR emissive spectra attributed to the trianion, Cor(super 3.-), and to the photoelectron, e(super -)(sub photo). The effect is observed within a temperature range of 176-230 K. Spin polarization occurs through three distinct mechanisms viz, triplet mechanism, S-T(sub -1) radical pair mechanism and radical triplet pair mechanism.

Nuclear magnetic resonance and electron paramagnetic resonance spectroscopies of the corannulene reduction indicate a stable diamagnetic dianion and negligible counterion effects in the mono- and dianion. The reduced form of trianion and tetraanion is obtained with lithium as the reducing metaly, but not with potassium. The anions with lithium and potassium are counterions.

A novel four-step synthesis of (1-13c)biphenyl from (7-13c)benzoic acid is presented. Treatment of the product with AlX3 H20 in benzene resulted in scrambling of the isotopic label in the biphenyl, especially with 10:1 AlBr3 H20 which can effect a complete equilbration of the label to all of the positions in the biphenyl. Monitoring of the progress of the reactions showed that the label starts to appear first in the ortho position, then in the meta position, and lastly in the para position.

A new synthetic methodology enables the preparation of the permethylated and perspirocycloproponated cyclotetradeca-1,3,6,9,12-pentayne. X-ray crystallographic and spectroscopic studies show that in the permethylated pentayne, compression of the internal C-C-C bond angles at the saturated carbon atoms surrounding the diyne increases the through-space Pi-orbital interactions, resulting in a bathochromic shift. Wider internal C-C-C band angles of perspirocyclopropanated pentayne decrease the through-space Pi-orbital interaction, while spirocyclopropanation increases the through-bond Pi-orbital interactions.

The synthesis and characterization of dicyclopenta(cd,mn)pyrene, dicyclopenta(cd,jk)pyrene and dicyclopenta(cd,fg)pyrene. are discussed. The three isomeric dicyclopentapyrenes were prepared via intramolecular trapping of vinylidenes which were thermally generated from terminal acetylenes. According to their nuclear magnetic resonance spectra, dicyclopenta(cd,jk)pyrene and dicyclopenta(cd,fg)pyrene are similar to dicyclopentanaphthalene (pyracylene) in that they have an antiaromatic 4N pi-electron perimeter that produces a paramagnetic ring current.

Oxidative cyclization of 1,1E-binaphthyl to perylene is achieved in quantitative yield by the action of three or more equivalents of potassium metal in hot tetrahydrofuran. Anionic cyclodehydrogenations are complementary to those performed under strongly acidic/oxidizing conditions, photochemically, or thermally.

A clean diels-alder reaction between bisanthene and diethyl acetylenedicarboxylate in presence of hot toluene to yield a rearomatized 1:1 cycloadduct and a rearomatized 2:1 cycloadduct is reported. A Diels-Alder cycloaddition/rearomatization strategy in presence of acetylene or a 'masked acetylene' as the dienophile could be used to grow single-chirality carbon nanotubes from suitable hydrocarbon templates, without metal catalysis.

Syntheses and X-ray crystal structures for all seven members of the indenocorannulene family, comprising indenocorannulene, both isomers of diindenocorannulene, both isomers of triindenocorannulene, tetraindenocorannulene, and pentaindenocorannulene are reported. The results demonstrated for the first time the extended [pi]-systems with curvatures exceeding those of the most curved stable fullerenes and carbon nanotubes that could be generated by ordinary laboratory methods in solution, without recourse to high-temperature gas phase methods, such as flash vacuum pyrolysis.

[super 1]H and [super 13]C chemical shifts were used to compute ab initio current densities induced by an external magnetic field for corannulene dianion, dication, and tetranion. The results showed that the dianion and dication are both 2p systems characterized by a single highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) rotationally allowed transition.

The dynamic stereochemistry of bicorannulenyl is analyzed by using a combined experimental and theoretical approach. The studies have shown that the energetically most favorable enantiomerization pathway has passed through one of the two achiral transition states and ha provided information on packing modes of bicorannulenyl molecules in the solid state.

Quantum mechanical density functional theory was used to determine the optical and electrochemical properties of aniline trimers. Aniline trimers are used in wide range of application due to its superior solubility to polyaniline and effective corrosion inhibition.

The fullerene-like chemistry exhibited by alkene-centered [C.sub.26][H.sub.12] geodesic polyarene, unlike of 2-dimensional polycyclic aromatic hydrocarbons is investigated. The addition of electrophilic and neutrophilic reagents at the interior carbon atoms of the central 6:6 bond, resulting in carbon atom pyramidalization, gives it fullerene like reactivity.

The study describes a methodological development strategy and provides mechanistic insight into the temperature, solvent and solubility effects of the trisannulated benzene derivatives, which is synthesized from the acid catalyzed cyclomerizations of the cyclic ketones. The analysis shows that the polarizable, as well as polar solvents are best for the aromatic ketones, whereas a standardized protocol can be used for all the test cases.

The [super 13]C chemical shift tensors measured from two-dimensional (2D) FIREMAT on 4,7-di-t-butylacenaphthene and 4,7-di-t-butyl-acenaphthylene is described along with a series of calculations on both compounds. The experiments have revealed a break in symmetry caused by the crystal packing that has given rise to additional spectral lines beyond those that would predict on the basis of molecular symmetry in an isolated molecule.

The synthesis and X-ray crystal structures of two new geodesic polyarenes, pentaindenocorannulene ([C.sub.50][H.sub.20]) and tetraindenocorannulene ([C.sub.44][H.sub.18]) are described. These extended aromatic [pi] systems form the largest curved subunits of [C.sub.60] and the trigonal carbon atoms at the core of these hydrocarbons suffer greater pyramidalization than that exhibited by the carbon atoms of [C.sub.60].

Geodesic polyarenes constitute a rapidly growing family of polycyclic aromatic hydrocarbons (PAHs) that resemble the geodesic domes of the great 20th century American architect Buckminster Fuller. It is possible to prepare number of bowl shaped PAH ring systems and study their chemical properties by employing syntheses based on flash vacuum pyrolysis (FVP).

The aryl radicals generated ortho to aryl substituents by flash vacuum pyrolysis (FVP) of the related aryl chlorides that have the ability to transfer hydrogen atoms between the ortho and ortho' sites (1,4 shifts of hydrogen atoms). It is found that in a restricted demonstration in similar situation, the FVP of 2 phenylbenzo[c]phenanthrene that does not have an important precursor mainly gives out the material used at start.

Pentakis(1,4-benzodithiino)corannulene in CS(sub 2) formed the strongest 1:1 complexes with C(sub 60) and C(sub 70) of any corannulene derivative yet reported. The 1,3,5,7,9-pentakis(propylthio)corannulene formed weaker 1:1 complexes with C(sub 60) and C(sub 70) in CS(sub 2), whereas the decakis(propylthio)-corannulene and unsubstituted corannulene showed no evidence for complexation with either C(sub 60) or C(sub 70) in CS(sub 2).

Critical assessments of the computational methods that perfectly reproduce the geometry of a representative geodesic polyarene, within the limits of two new high quality X-ray crystal structure are identified. B3LYP/6-31G calculations were found to correctly reproduce all of the experimental bond distances and bond angles within the limits of an extensive X-ray data set.

Unprecedented supramolecular stacks of highly reduced geodesic Pi-systems are prepared by the reduction of the derivatized fullerenes Me(sub 5)C(sub 60)H and Ph(sub 5)C(sub 60)H and corannulene with lithium metal. The high stability of these new supramolecular assemblies enables the introduction of another organization motif to the system, which is achieved by using tethered corannulenes as host molecules.

A new strategy for examining the existence of polycyclic aromatic hydrocarbons (PAHs) in interstellar space is described. The laboratory spectroscopy that is required to implement this strategy is also discussed.