Hydrothermal Synthesis and X-Ray Single Crystal Structure of [Zn(en)2]6 [(VO)12O6B18O39(OH)3]·13H2O

A hydrothermal reaction of NaVO3, H3BO3, Zn(CH3COO)2, ethylenediamine, and H2O gives a coordination cluster [Zn(en) 2]6[(VO)12O6B18O39(OH)3]·13H2O (denoted on Zn6V12B18). The Zn6V12B18 crystallizes in a rhombohedral system with space group R-3 and unit cell parameters a=20.686(3) ?, c=20.915(4) ?, V=7751(2) ?3, Z=3, and R=0.0689. The structure consists of an 18-membered ring of B18O39(OH)3 sandwiched between two alternating edge-sharing vanadium–oxygen clusters V6O15 by six B–(mu 3–O)–V2 bonds and three B2–(mu 3–O)–V bonds. Each of the six zinc atoms coordinated with two ethylenediamine molecules and connected with the B18O39(OH)3 ring by one Zn-(mu 3–O)–B bond. A water molecule occupied the center of the Zn6V12B18 cluster. The oxidation states of vanadium in the compound are V(IV) and V(V) in a ratio of 3:1. Other characterizations by IR spectroscopy, TGA, and DTA are also described.