"Third-Generation"-Type Functional Tris(2-pyridyl)borate Ligands and Their Transition-Metal Complexes.

Phenyltris(2-pyridyl)borates (Tpyb) are a promising class of tripodal "scorpionate"-type ligands with potential utility in the development of transition-metal complexes with interesting optical, electronic, or magnetic properties and as building blocks to metallosupramolecular polymers. We report here a new class of "third-generation"-type Tpyb ligands that contain different functional groups attached to the boron-bound aryl moiety. The synthesis, characterization, and metal-ion complexation behavior of ligands with iodo and trimethylsilyl groups are discussed.