No abstract

Microwave heating was used to prepare eta5-rhenium carborane complexes in aqueous reaction media. For carboranes bearing sterically demanding substituents, isomerization of the cage from 3,1,2 to 2,1,8 derivatives occurred concomitantly with complexation. Microwave heating was equally effective at the tracer level using technetium-99m, affording access to a new class of synthons for designing novel molecular imaging agents.

An organometallic rhenium complex having high and selective affinity for α-adrenergic receptors is reported. A series of methoxyphenylpiperazinecarborane ligands complexed to the [Re(CO)(3)](+) core were prepared and the resulting organometallic compounds screened for binding to serotonin, σ, and adrenergic receptors as well as dopamine, serotonin, and norepinephrine transporters. An amide linked derivative, for which a single crystal X-ray structure was obtained, showed high and selective affinity toward α(1A), α(1D), and α(2C) adrenergic receptors with K(i) values of 17, 21, and 39 nM, respectively. A method to prepare the corresponding (99m)Tc complex was also developed where the resulting metallocarborane was shown to be stable and is therefore suitable for in vivo molecular imaging studies.

No abstract