QUANTIFICATION OF SUBSTITUENT AND LIGAND SIZE BY THE USE OF SOLID ANGLES

A new, generalized, method for measuring the steric size of ligands an d substituents has been developed. The method is based on the solid an gle concept, the solid angle being generated by the pairwise addition of spheres (atoms). The problem of overlapping spheres (atoms) has bee n solved analytically and the algorithm provided permits evaluation of the steric space occupied by any combination of spheres (atoms). A ra nge of solid angles for commonly encountered ligands and substituents has been determined and compared to literature values for linear cone angles. (C) 1993 by John Wiley & Sons, Inc.