On the Stability of Trimeric Beryllium Hydroxide Scorpionate Complexes

The controlled hydrolysis of TpBeCl {Tp = trispyrazolylborate [HB(C3N2H3)(3)](-)} with H2O and D2O in the presence of N,N-diisopropylethylamine (DIPEA) yields the trimeric beryllium hydroxide scorpionate complexes [Be-3(mu-OX)(3)(Tp)(3)] (X = H: 1, D: 2) quantitatively. The complexes contain six-membered Be3O3 rings according to single-crystal X-ray diffraction studies and theoretical calculations. Temperature-dependent H-1 and Be-9 NMR spectroscopy established that 1 has a dynamic structure in solution. In addition, the structure of [Be-3(mu-OH)(3)(Br)(3)(thf)(6)], which was obtained from hydrolysis of a solution of BeBr2 in tetrahydrofuran and CHCl3, is reported.