QD-2: a novel open-framework aluminoborate with intersecting three-dimensional helical channels.

A novel open-framework aluminoborate, [CH3NH2(CH2)3NH ]-[AlB5O10] (QD-2), has been synthesized under hydrothermal conditions and characterized by IR, elemental analysis, thermogravimetric analysis, and powder and single-crystal X-ray diffractions. The compound crystallizes in the orthorhombic system, space group P2(1)2(1)2(1) (No. 19), a = 9.4352(4) A, b = 10.2972(2) A, c = 13.7511(5) A, V = 1336.0(8) A3, and Z = 4. Its structure consists of AlO4 tetrahedra and B5O10 clusters, which are interconnected to form the first example of a three-dimensional aluminoborate with intersecting helical channels.