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

A new hydrated borate compound, [NH3CH2CHCH3NH3]][B8O11(OH)4]·H2O 1, has been synthesized in the presence of 1,2-diaminopropane 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 1 crystallizes in the monoclinic system, space group P21/c (No. 14), a=10.0787(7) Å, b=8.8482(6) Å, c=19.3097(4) Å, β=91.352(6)°, V=1721.53(2) Å3, 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.

Graphical abstractOne new organically templated borate [NH3CH2CHCH3NH3]][B8O11(OH)4]·H2O 1, has been synthesized under mild hydrothermal conditions. Its structure features an unusual open-branched borate chain constructed from [B3O6(OH)] groups, onto which the [B5O7(OH)3] groups are grafted. It is the first instance of 1D borate templated by the organic amine. Adjacent borate chains are linked together by multipoint bonds to form interesting three-dimensional network with rhombus-like channels, in which the guest water and diprotonated organic amine molecules reside.Figure optionsDownload full-size imageDownload as PowerPoint slide