Efficient Hydride and Pyrazolyl Redistribution upon Thermolysis of a Calcium Complex Containing Dihydrobis(pyrazolyl)borate Ligands

Thermolysis of CaBp<sub>2</sub>(THF)<sub>2</sub> (THF = tetrahydrofuran) at 190–200 °C and 0.05 Torr leads to a redistribution reaction to afford CaTp<sub>2</sub> (90%) and CaTp(BH<sub>4</sub>) (84%). Treatment of CaTp(BH<sub>4</sub>) with THF affords CaTp(BH<sub>4</sub>)(THF)<sub>2</sub> and [CaTp(BH<sub>4</sub>)(THF)]<sub>4</sub>, both of which were structurally characterized. Methanolysis or ethanolysis/hydrolysis of the BH<sub>4</sub><sup>–</sup>-containing complexes affords [TpCa(HOMe)<sub>2</sub>(μ<sub>4</sub>-B(OMe)<sub>4</sub>)Ca(HOMe)<sub>2</sub>Tp][B(OMe)<sub>4</sub>] and [{TpCa}<sub>3</sub>{μ<sub>6</sub>-B(OB(OEt)<sub>3</sub>)<sub>3</sub>]·EtOH.