Syntheses and crystal structures of two new organically templated borates

Two new organically templated borates, [H ₃N(C ₆H ₁₀)NH ₃][B ₄O ₅(OH) ₄] (1) and [H ₃N(C ₆H ₁₀)NH ₃][B ₅O ₈(OH)] (2) have been synthesized in the presence of trans-1,4-diaminocyclohexane acting as a structure-directing agent under mild solvothermal conditions. The structures were determined by single crystal X-ray diffraction and further characterized by FTIR, elemental analysis and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic system, space group C2/c (No. 15), a=9.1325(3)Å, b=11.4869(3)Å, c=12.2756(5)Å, β=105.258(6)°, V=1242.37(7)Å3, Z=4. The structure contains supramolecular hydrogen-bonded network formed by isolated [B ₄O ₅(OH) ₄] ^2- polyanions. 2 is monoclinic, space group P2(1)/n (No. 14), a=6.5176(2)Å, b=16.8861(5)Å, c=11.1522(7)Å, β=91.897(6)°, V=1226.70(9)Å3, Z=4. The structure consists of layers of 3,9-membered boron rings constructed from pentaborate anion groups [B ₅O ₈(OH)] ^2-. The adjacent borate layers are further linked with each other by hydrogen bond to form a 3D supramolecular network. It is the first example of layered borates templated by an organic amine. Two new organically templated borates, [H ₃N(C ₆H ₁₀)NH ₃] [B ₄O ₅(OH) ₄] (1) and [H ₃N(C ₆H ₁₀)NH ₃] [B ₅O ₈(OH)] (2) have been synthesized in the presence of trans-1,4-diaminocyclohexane acting as a structure-directing agent under mild solvothermal conditions. Compound 1 is supramolecular hydrogen-bonded network formed by isolated [B ₄O ₅(OH) ₄] ^2- polyanions, while 2 is the first example of layered borates, consisting of 3,9-membered boron rings, templated by an organic amine. The layers further connect each other by hydrogen bonds, forming extra large channels containing 14-membered boron rings.