Structural measures of element–oxygen bond covalency from the changes to the delocalisation of the carboxylate ligand†
Abstract
The data set of more than 40,000 crystal structures containing the carboxylate group that have been deposited in the CSD has been used to examine the structural changes that occur in the carboxylate C–O bond lengths upon binding to different elemental centres. We report here quantifiable structural changes that are dependent on the elemental centre with which the group is interacting. For the main-group elements the trends are entirely periodic and follow those traditionally associated with covalency; elements exhibiting electronegativity closest to that of oxygen exhibit the largest structural change. In addition, we find the measure is extendable to both the transition metals and the