Quantitative study of the structure-stability relationship of TcvO(III) complexes.

Abstract By studying structural parameters (van der Waals radius and bond length from x-ray crystallography) of more than 100 known Tc compounds and using the cone packing model, a stability indicator of the Tc compounds was derived. The indicator is based on the solid angle factor sum (SAS), which is calculated from van der Waals radii and bond lengths between all coordinating atoms and Tc. The average SAS value is 0.97 ± 0.13. The SAS value reflects the limits of the packing of ligand around Tc. The quantitative calculation of the SAS is useful for predicting stability and designing new Tc radiopharmaceuticals.