[NH3CH2CHCH3NH3][B8O11(OH)4]•H2O:: Synthesis and characterization of the first 1D borate templated by 1,2-diaminopropane

A new hydrated borate compound, [NH3CH2CHCH3NH3]][B(8)O11(OH)(4)].H2O 1, has been synthesized in the presence of 1,2diaminopropane acting as a structure-directing agent under mild conditions. Its structure was determined by single crystal X-ray diffraction and further characterized FTIR, elemental analysis, powder X-ray diffraction and thermogravimetric analysis. Compound I crystallizes in the monoclinic system, space group P21/c (No. 14), a = 10.0787(7)angstrom, b = 8.8482(6) angstrom, c = 19.3097(4) angstrom, beta = 91.352(6)degrees, V = 1721.53(2)angstrom(3), and Z = 4. The structure consists of infinite open-branched borate chains constructed from [B3O6(OH)] units, onto which the [B5O7(OH)(3)] groups are grafted. It represents the first example of one-dimensional borate templated by an organic amine. The adjacent borate chains are further linked together by extensive hydrogen bonds to form a 3D supramolecular network. The diprotonated organic amines and guest water molecules are filled in the free space of the hydrogen-bonded network and interact with the inorganic framework by extensive hydrogen bonds. (C) 2007 Elsevier Inc. All rights reserved.