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

Thermolysis of CaBp₂(THF)₂ (THF = tetrahydrofuran) at 190–200 °C and 0.05 Torr leads to a redistribution reaction to afford CaTp₂ (90%) and CaTp(BH₄) (84%). Treatment of CaTp(BH₄) with THF affords CaTp(BH₄)(THF)₂ and [CaTp(BH₄)(THF)]₄, both of which were structurally characterized. Methanolysis or ethanolysis/hydrolysis of the BH₄^–-containing complexes affords [TpCa(HOMe)₂(μ₄-B(OMe)₄)Ca(HOMe)₂Tp][B(OMe)₄] and [{TpCa}₃{μ₆-B(OB(OEt)₃)₃]·EtOH.