Synthesis and Structural Characterization of Bis(2-oxoimidazolyl)hydroborato Complexes: A New Class of Bidentate Oxygen-Donor Ligands

A new class of bidentate ligands that feature oxygen donors, namely, the bis­(2-oxo-1-tert-butylimidazolyl)­hydroborato and bis­(2-oxo-1-methyl­benz­imid­azolyl)­hydroborato ligands, [BoBut] and [BoMeBenz], have been synthesized via the reactions of MBH4 with 2 equiv of the respective 2-imidazolone. Chelation of [BoBut] and [BoMeBenz] to a metal center results in a flexible eight-membered ring that is capable of adopting a “boatlike” conformation that allows for secondary M···H–B interactions.