X-ray crystallographic study of neutral boron chelates with ?-diketones and tropolone

A series of six new boron ?-diketonates and tropolonates has been synthesized, each compound being crystallized and characterized by spectroscopic methods as well as by X-ray crystallography. A comparative study of the NMR and X-ray data with similar structures from the literature permitted us to develop a detailed evaluation of the bonding in these chelates that lead to several interesting correlations. The present compounds have important physical properties that justify this study. 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:359368, 1998