Synthesis and crystal structure of inclusion compounds: Trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid with boric acid and tetrabutylammonium salt

Abstract

Two new inclusion compounds (n-C₄H₉)₄N⁺C₁₈H₁₃O₄^- &middo; B(OH)₃ (1) and (n-C₄H₉)₄N⁺C₁₈H₁₃O₄^- (2) were prepared and characterized by X-ray crystallography. Crystal data: compound 1, monoclinic P2(1)/c, a = 1.569 9(1) nm, b = 0.995 5(6) nm,c = 2.293 3(1) nm, β = 109.962(3)º, Z = 4, and R₁ = 0.0434, wR = 0.075 9; compound 2, monoclinic C2/c, a = 1.400 5(3) nm, b = 1.282 1(2) nm, c = 1.765 7(3) nm, β = 100.388(1)º, Z = 4, and R₁ = 0.0584, wR = 0.096 6. In the crystal structure of 1, the tetramers formed by two trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (EADA) anions and two boric acid molecules were connected through O H…O hydrogen bonds to generate a channel type host lattice. The tetra-n-butylammonium cations were stacked to give two columns within each channel with cross-sectional size of about 2.30 nm×0.93 nm. In the crystal structure of 2, similar honeycomb host lattices with big size were also formed along the [101] direction by three-dimensional accumulation of EADA anions. The tetra-n-butylammonium cations were accommodated in a zigzag fashion within each channel.