Syntheses and crystal structures of two new pentaborates

Two new zinc pentaborates, [Zn(DIEN)2][B5O6(OH)4]2 (I) and [B5O7(OH)3Zn(TREN)] (II), have been synthesized under hydrothermal conditions. Compound I is a new pentaborate templated by a transition-metal complex, while II is a novel transition-metal complex supported pentaborate, which provides the first example of the combination of B-O cluster with transition-metal complex.