On the characterization of the surface chemistry of quantum dots.

The interaction of ligands with the surface of quantum dots (QD) was studied using tritiated oleic acid as an ultrasensitive reporter. The use of labeled oleic acid not only permitted to quantify the number of ligands attached to the surface of QDs of various sizes but also enabled the investigation of the relative affinity of different ligand types for the nanocrystal's surface.

Measurement of long-range interatomic distances by solid-state tritium-NMR spectroscopy.

For the structural determination of a ligand bound to an amorphous macromolecular system, solid-state NMR can be used to provide interatomic distances. It is shown here that selective labeling in discrete locations with tritium enables accurate measurement of long-range distances owing to the high gyromagnetic ratio of this nucleus, without structural modification of the molecule. This approach gives access to the largest NMR distance ever measured between two nuclei (14.4 A). (3)H MAS NMR appears to be a promising tool for structural applications in the biological and material sciences.

Synthesis and evaluation of photoreactive probes to elucidate iodide efflux in thyrocytes.

Four photoreactive analogues of 3-biphenyl-4'-yl-5,6-dihydroimidazo[2,1-b]thiazole were prepared and evaluated as iodide sequestering agents in sodium iodide symporter-expressing cells. One of these new photoactivatable compounds retained biological activity and was further radiolabeled with tritium. This compound may provide a useful tool for labeling, purification, and identification of target protein responsible for iodide efflux in thyrocytes.

Enantioselective synthesis of levomilnacipran.

A novel approach for the asymmetric synthesis of the active (1S,2R)-enantiomer of the antidepressant milnacipran is reported. The two stereogenic centers borne by the cyclopropane ring were sequentially installed starting from phenylacetic acid.

Highly chemoselective hydrogenolysis of iodoarenes.

The catalytic hydrodehalogenation reaction using molecular hydrogen and Pd/C has been revisited. It is shown that the speed of removal of halogen increases with increasing electronegativity I < Br < Cl. Nevertheless, selective dehydrohalogenation in compounds containing other reducible functions can be achieved only with iodine and not with bromine or chlorine. Selective deiodination of iodobenzophenone could be accomplished without reducing the carbonyl group. Hydrogenolysis of azidoiodoaromatic compounds to the corresponding azido compounds is high yielding. This selectivity was exploited for the labeling of benzophenone- and azido-containing compounds by deuterium and tritium.