Preparation and crystal structures of an ionic triple-hydrogen-bridged derivative of 9-BBN hydroborate zirconium(IV)

An ionic dinuclear triple-hydrogen-bridged 9-BBN hydroborate zirconium complex, [K(Et2O)4][{(μ-H)2BC8H14}3Zr(μ-H)3Zr{(μ-H)2BC8H14}3] (1) was formed from the reaction of Zr{(μ-H)2BC8H14}4 with KH and aniline in diethyl ether. The molecular structure of compound 1 was determined by single-crystal X-ray diffraction analysis. Six 9-BBN hydroborate ligands are coordinated to two Zr atoms via two bridging H atoms, and two Zr atoms are connected by three bridging hydrogens in the anion part of this molecule. The distance of Zr⋯Zr is 3.1025(5) Å. The crystal structure of 1 suggests that agostic interactions between the zirconium metal center and α-C–H of the 9-BBN hydroborate ligand exist in the solid state. The Zr⋯H distances corresponding to the α-C–H⋯Zr agostic interactions are 2.579(4) Å and 2.743(4) Å.