Syntheses and crystal structures of two new pentaborates

Two new pentaborates, [Zn(DIEN)(2)][B5O6(OH)(4)](2) (DIEN = diethylenetriamine) (I) and [B5O7(OH)(3)Zn(TREN)] (TREN-tris(2-aminoethyl)amine) (11), have been hydrothermally synthesized and characterized by single crystal X-ray diffraction, FTIR, elemental analysis and thermogravimetric analysis. Compound I crystallizes in the monoclinic system, space group P2(1)/c (No. 14), a = 8.5686(2)angstrom, b = 11.7883(3)angstrom, = 14.5407(6)angstrom, beta = 91.259(2)degrees, V = 1468.39(8)angstrom, Z = 2. The structure consists of isolated borate polyanion [B5O6(OH)(4)](-) and zinc complex cation [Zn(DIEN)2]2 The anionic units, [B5O6(OH)(4)](-), are linked by hydrogen bonds to form a 3D supramolecular network containing large channels, in which the templating [Zn(DIEN)(2)](2+) cation are located. 11 is monoclinic, P2(1)/c (No. 14), a = 8.9969(2)angstrom, b = 20.6903(6)angstrom, c = 9.2878(3)angstrom, beta 99.635(2)degrees, V = 1704.52(8)angstrom , Z = 4. The structure of II is constructed from two distinct motifs, a usual [B5O7(OH)(3)](2-) cluster and a supporting zinc complex [Zn(TREN)](2+), which are integrated through Zn-O-B linkage. This compound represents the first example of the combination of B-O cluster with transition-metal complex. (c) 2004 Elsevier Inc. All rights reserved.