Calibrating the coordination chemistry tool chest: metrics of bi- and tridentate ligands.

Bi- and multidentate ligands form part of the tools commonly used for designing coordination and supramolecular complexes with desired stereochemistries. Parameters and concepts usually employed include the normalized bite of bidentate ligands, their cis- or trans-coordinating ability, their rigidity or flexibility, or the duality of some ligands that can act in chelating or dinucleating modes. In this contribution we present a structural database study of over one hundred bi- and tridentate ligands that allows us to parametrize their coordinating properties and discuss the relevance of such parameters for the choice of coordination polyhedron or coordination sites.