Exploring molecular structures, orbital interactions, intramolecular proton-transfer reaction kinetics, electronic transitions and complexation of 3-hydroxycoumarin species using DFT methods.

Optimal structures and electronic properties of various species of 3-hydroxycoumarin (3-HCou) have been explored using density functional theory (DFT) methods under polarizable continuum model (PCM) of solvation. Electron transfer from pyrone to benzene moieties is enhanced upon deprotonation. Anionic and radical species have similar orbital-interaction characteristics but the charges in the former are distributed more uniformly.

Insight into technetium amidoxime complex: oxo technetium(V) complex of N-substituted benzamidoxime as new basic structure for molecular imaging.

In search of benzamidoxime (BHam) derivatives that provide a single (99m)Tc-labeled compound of high in vivo stability, we synthesized three N-alkyl compounds of benzamidoxime (BHam) ligand. They provided a single (99m)Tc-labeled compound by ligand exchange reaction of (99m)Tc-glucoheptonate in high radiochemical yields (over 95% at MBHam concentration of 1 × 10(-5) M). (99m)Tc-N-methyl benzamidoxime ((99m)Tc-MBHam) showed higher stability than the parental (99m)Tc-BHam.

Assessment of macrocyclic triamine ligands as synthons for organometallic 99mTc radiopharmaceuticals.

In a search of coordination molecules suitable to the fac-{(99m)Tc(CO)3}(+) core as a synthon for (99m)Tc-radiopharmaceuticals, nonradioactive rhenium complexes of two macrocyclic triamine compounds with different chelate ring structures, 1,4,7-triazacyclononane (9N3) and 1,5,9-triazacyclododecane (12N3), were synthesized and characterized. (99m)Tc-labeled 9N3 and 12N3 compounds were also prepared using [(99m)Tc(OH 2)3(CO)3](+) and were characterized by both in vitro and in vivo studies. 9N3 produced a single rhenium complex, whereas 12N3 generated two major complexes.