[Ln(BH4)2(THF)2](Ln = Eu, Yb)-A highly luminescent material. Synthesis, properties, reactivity, and NMR studies

Article abstract of DOI:10.1021/ja308077t

The divalent lanthanide borohydrides [Ln(BH₄) ₂(THF)₂] (Ln = Eu, Yb) have been prepared in a straightforward approach. The europium compound shows blue luminescence in the solid state, having a quantum yield of 75%. Nonradiative deactivation of C-H and B-H oscillator groups could be excluded in the perdeuterated complex [Eu(BD₄)₂(d₈-THF)₂], which showed a quantum yield of 93%. The monocationic species [Ln(BH₄)(THF) ₅][BPh₄] and the bis(phosphinimino)methanides [{(Me ₃SiNPPh₂)₂CH}Ln(BH₄)(THF) ₂] have been prepared from [Ln(BH₄)₂(THF) ₂]. They show significantly lower or no luminescence. Using the diamagnetic compound [{(Me₃SiNPPh₂)₂CH} Yb(BH₄)(THF)₂], we performed a 2D ³¹P/ ¹⁷¹Yb HMQC experiment.