Shashadhar Samal

Unexpected solute aggregation in water on dilution

Studies on cluster-cluster aggregation phenomena in aqueous solutions of fullerene-cyclodextrin conjugates, beta-cyclodextrin, sodium chloride, sodium guanosine monophosphate, and a DNA oligonucleotide revealed that there are larger aggregates existent in dilute aqueous solutions than in more concentrated solutions.

Cyclodextrin–fullerenes: a new class ofwater-soluble fullerenes

Solubilization of fullerenes in water by nucleophilic addition of cyclodextrin-R-monoamines to C60, where R represents iminoalkyl and iminoaryl residues, is reported and studies involving the host–guest characteristics, free radical scavenging and DNA-cleaving properties indicate that this class of compounds has potential for a number of biological and medical applications.

DNA-Cleavage by Fullerene-Based Synzymes

Efficient cleaving of DNA oligonucleotides by a water-soluble fullerene main-chain polymer is demonstrated following a facile routine of monitoring the reaction by UV-vis spectroscopy and separating the cleaved fractions by membrane filtration. A small quantity of the fullerene derivative could cleave a large excess of the oligonucleotide under ambient light conditions, leading to cleaved DNA in quantitative yields.

The first water-soluble main-chain polyfullerene

The synthesis of the first water-soluble polyfullerene is accomplished by nucleophilic reaction of a diamine supramolecularly shielded in a cyclodextrin cavity with fullerene, leading to a versatile new field for main-chain fullerene polymers.

A new macroporous luminescent hydrogel from poly(allylamine)

The synthesis of a novel highly swelling, macroporous hydrogel from poly(allylamine) using 3-chloropentan-2,4-dione as a crosslinker is reported. The swelling of the hydrogel was sensitive to changes in pH, temperature, and the extent of crosslinking. The dry gel exhibited a regular honeycomb network with smooth macropores. The hydrogel was inherently luminescent, and so was a metal polychelate.

THE FIRST SYNTHESIS OF WATER-SOLUBLE CYCLODEXTRINAZAFULLERENES

ABSTRACT The synthesis of highly water-soluble cyclodextrinazafullerenes by reacting azidocyclodextrins with C60 is reported. The aqueous solubility was directly related to the solubility behavior of the attached cyclodextrin moiety.

Macromolecular and Supramolecular Architectures Based on Fullerenes

The fullerenes with the π-electron orbitals extending outward provide an excellent opportunity for a variety of orbital-orbital interactions with molecules appropriately positioned close to their surface. The extent of these interactions is dependent on the π- electron availability, shape, and dimension of the interacting molecules. The typical arrangement of the five- and the six-membered rings in C60 lead to a spherical shape. When five-membered ring is attached to six-membered rings on each side, each carrying three alternate π-bonds in such away that none of the π-bonds are in the 5,6-ring junctions, and the structure is energy-minimized, the result is a curved surface (Figure 1a). On the curved exterior of such a surface, the π-bonds are bent (Figure 1b).