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A study was conducted to investigate the double Diels-Alder cycloaddition of two tethered isobenzofurans to the fullerene [C.sub.60]. The method helps to easily perform the saturation of two of the three C=C double bonds within a six-membered ring of [C.sub.60] and provides the means of saturating the remaining double bond of a six-membered ring of [C.sub.60] via the side chains of the isobenzofurans with suitably reactive functional groups.

The 2-azaphenalenyl radical 2 is synthesized and characterized by ESR spectroscopy. Variable-temperature ESR measurements were carried out on both the phenalenyl and the 2-azaphenalenyl radicals.

Research has been conducted on the diastereomeric tetrakisfulleroids. The synthesis of these compounds carried out via the use of trans-1 bis-Diels-Alder adduct is described.

The formation of several 1,2-bisketenes by the photolysis of cyclobutenediones has been studied, and time-resolved infrared spectroscopy has been used to observe the species. UV spectroscopy was used to measure the rates of thermal conversion of 1,2-bisketenes back to cyclobutenediones, including ketenes with CN,super6, Br,super7 alkynyl,super8 thio,super9 and alkoxysuper10 substituents.

C60 unit undergoes Diels-Alder reaction with 1,3-dienes to form the ball-and-chain system having C60 and donor-substituted aryl chromophores linked through a rigid saturated polynorbornane-bicyclo(2.2.0)hexane hydrocarbon bridge. A similar reaction of bis(diene) forms soluble dumb-bell system having two C60 chromophores. The norbornylogous bridge transfers electrons and energy by a strong through-bond coupling mechanism. Ab initio, semi-empirical, and molecular mechanics show that activation barriers between folded and extended conformers have a consistent value.

The special symmetry properties of fullerene pi-system allow strong electron coupling with the tetraalkyl-p-phenylenediamine donor hydrocarbon bridge to allow photoinduced electron transfer. Photoexcitation in (C60(3)TMPD) system results in a complete intramolecular charge separation and is independent of solvent polarity. The charge separated states are not detected due to fast charge recombination. In (C60(11)DMA), the photoinduced charge separation occurs only in polar solvents like benzonitrile and the dipolar state can be detected because of the slow rate of charge recombination.

The synthesis of nanosized molecular allotropes of carbon and rigid fullerene-rich polymers is made possible by utilizing fullerenes with solubilizing fragments which are easily withdrawn. The transformation of t-BOC to C60 includes the in situ production of diene which suffer (4+2) cycloaddition with dimethyl acetylenedicarboxylate giving the bicyclic complex, which on fast cycloreversion lead to C60 and dimethyl phthalate.

The lithium salt of a specific hydrazone was reacted with C60 to yield diethynylmethanobuckministerfullerene, which was subjected to desilylation. CI-TQMS, IR, UV-vis and NMR spectroscopies were used to characterize this compound. Buckministerfullerene produced single oxygen to inhibit HIV-1 protease and promote DNA cleavage. The diethynyl compound was found in macrocyclic and polymeric carbon allotropes.

The Diels-Alder functionalization and the verification of alcohol with alpha-benzyl N-(tert-butoxycarbonyl)-L- glutamate, and N-(benzyloxycarbonyl)-L-alamine were used to prepare the first alpha amino acid derivatives of C60. The reduction of ketone, obtained in good yield by the Diels Alder reaction of 2-(trimethylsiyl)oxy-1,3-butadiene with C60, results in the formation of 1, 9-(4-hydroxycyclohexano) buckminster fullerene.

A molecular approach is described to the control of both the length-scale of polymer/fullerene phase segregation and the electron mobility in the fullerene network. Bulk heterojunction solar cells are studied in order to understand how molecular control over fullerene-fullerene interactions might translate into a favorable BHJ morphology and thus improve electron mobility and photovoltaic device performance.

The set of remarkable systems for exploring atomic interactions and molecular dynamics are provided by trapping the atoms and molecules inside the fullenrene cages. The H NMR measurements on the endohederal H2@AOCF in solid state is described.

Fullerenes are unparalleled among carbon-based molecules in their combination of structural, topological, and electronic features. The methodology is described which allows a straightforward insertion of a C(sub 2) unit onto the framework of C(sub 60) giving stable C(sub 62) derivatives in a one-pot synthesis.

Research is presented concerning the control of regioselectivity in fullerene. The precise nature of the control which can be achieved of the regiochemistry around the coordination core of fullerene C60 is discussed.

A report of research using a rational synthetic approach into the non-classical fullerene C62 which incorporates a four-membered ring.

A facile synthetic route to the precursor of fulleropyrrolidine hexanitroxide is described and the discovery of a novel hexaadduct with D3 symmetry is reported. The large steric bias of the tetramethyl azomethine ylide was found to be important in increasing the selectivity for hexapyrrolidine synthesis. Meanwhile, the novel hexaadduct exhibits remarkable symmetry which has no precedence in fullerene chemistry. Its six addends are either in cis-3, e, trans-3 or trans-2 relationships and shows strong luminescence indicative of photophysical properties that are unusual compared with other fullerene derivatives.

The Hay coupling reaction of 1,2-diacetylene led to the formation of the oactaalkynyldibenzooctadehydro[12]-annulene cyclic dimer. X-ray structural analysis of octaalkynyldebenzooctadehydro[12]-annulene indicated the presence of bond elongations within the [12]-annulene and benzene rings along the C2-axis that traversed the six-membered rings of the compound. The cyclic dimer exhibited unusual stability due to the steric shielding of the strained [12]-annulene moiety by bulky t-Bu groups and CHCl3 molecules in the packing structure.

Synthesis of the acetylenic cyclophane from polyalkynyl precursors is a precise step towards the rational synthesis of endohedral metal fullerene complexes. The pathway starts with the bromination of 1,3,5-triethynylbenzene with NBS producing tris(bromoalkyne). A brief two-step sequence ends with the production of the acetylenic cyclophane. The cyclophane shows a helical chiral nature in the ORTEP plot of its crystal structure. The energy of transition state between its enantiomers indicates that, probably, racemization of the cyclophane occurs very fast.

Diels-Alder functionalization of fullerenes forms C-60 fused cyclohexenes which retain the photochemical properties of the parent compounds. Photosensitized generation of oxygen by the adducts has altered the regioselective properties originally exhibited by the cyclohexene framework. The reverse regioselectivity of the cycloaddition products is discussed in conformational and electrostatic terms.

A new technique for synthesizing sterically crowded fullerene derivatives has been developed. The diastereomeric alcohol involved was successfully prepared and its availability enabled the inhibition of HIV-1 protease. Dienolate anions were added in a 'double-Michael' scheme to C60 to form an anionic intermediate.

Investigation of the photophysical properties of a dihydrofullerene, the C60 adduct 1, 9-(4-hydroxycyclohexano)buckminsterfullerene, shows that its photoprocesses are similar to those of C60. It produces singlet oxygen, but its quantum yield is less than that of C60 and triplet-triplet absorption spectrum is similar to that of C60. It has lower singlet and triplet energies compared to C60, and carbon-substituted dihydrofullerenes exhibit similar characteristics to dihydrofullerene.

Investigations aimed at designing a unique kind of derivative of C60 by building 'ball-and-chain' mechanisms, where the C60 unit and another functional group, G, are connected to a rigid polycyclid chain or bridge, used the Diels-Alder reaction between C60 and the unique bridge diene 6 to synthesize a 'ball-and-chain' molecule (2) where the chain consists of a rigid polynorbornyl-bicyclo(2.2.0)hexyl bridge used in the building of many donor-bridge-acceptor mechanisms. The rational construction of unique molecular electronic equipment could use the photophysical, chemical and electrical characteristics of these 'ball-and-chain' bichromophoric systems as materials.

A study was done on the Diels-Alder reactions of buckminsterfullerene with anthracene, furan and cyclopentadiene. These Diels-Alders adducts were characterized using a concept in which the aromatization of intermediate 3 provides increased overall stability to the resulting adduct 1. The results show that the stabilization energy derived from the aromatic system must be overcome in order for compound 1 to undergo retro-Diels-Alder reaction.