Differences between the macroscopic and tracer level chemistry of rhenium and technetium: contrasting cage isomerisation behaviour of Re(i) and Tc(i) carborane complexes

Abstract

Carboranes form stable complexes with the [M(CO)₃]⁺ (M = ^99mTc, Re) core and are viable ligands for the development of targeted radiopharmaceuticals. ^99mTc-carborane complexes were found to exhibit substantially different 1,2→1,7 cage isomerisation behaviour than their Re counterparts, challenging the validity of the routine use of rhenium as a surrogate for the development of technetium-99m based molecular imaging agents.