The Extension of the Solid‐Angle Concept to Bidentate Ligands

Abstract

AbstractIn search of an applicable parameter to express the steric requirement of bidentate ligands, the generalised equivalent cone angle Θ–b is established. It is designed in the style of the solid‐angle concept for monodentate ligands, utilising crystal structure data. Its reliability is tested with bidentate phosphanes coordinated to a central platinum atom. Therefore, a detailed evaluation of the Cambridge Database for platinum complexes with bridging phosphanes is performed. Herein, we present the results of the analysis of more than 900 molecular structures and over 280 different bidentate phosphanes. We intend to establish diselenolatoplatinum(II) complexes as model compounds for the fast prediction of Θ–b instead of calculating a multiplicity of molecular structures that is often not available. The complexes reported in Part 1 of this publication turn out to be rather acceptable for rough estimates of the generalised equivalent cone angle. On the other hand, the compounds are used to demonstrate the practicability of the concept, which is easily extended to other bidentate ligands, as is shown for the 2,2‐bis(hydroxymethyl)‐1,3‐diselenolato moiety. In conclusion, the generalised equivalent cone angle Θ–b proves to be a feasible parameter for the steric demand of bidentate ligands.