Lariat-bearing cyclophosphazenes: potential molecular sepulchers for magnetic resonance imaging agents

Article abstract of DOI:10.1016/0022-2860(93)80291-3

Lariat-bearing cyclophosphazenes were prepared by aminolysis of hexachlorocyclotriphosphazene with amino ester hydrochlorides followed by standard alkaline hydrolysis.These cryptands are actually capable complexing gadolinium cations with stability constants larger than 1E28; this is much larger than the values for classical magnetic resonance imaging agents.Unfortunately, these cryptates are much too insoluble in physiological serum to be used for clinical purposes in a facile way.