Ethane-1,2-diaminium 4,4'-sulfonyl-dibenzoate

Crystal structure of tetrapropylammonium guanidinium 4,4′-sulfonyldibenzoate monohydrate, C27H44N4O7S

C27H44N4O7S, monoclinic, P21/n (no. 14), a = 10.216(3) Å, b = 18.133(5) Å, c = 17.036(5) Å, β = 98.371(3)°, V = 3122.2(16) Å3, Z = 4, R gt(F) = 0.0435, wR ref(F 2) = 0.1333, T = 296(2) K.

Composite host lattices of 4,4'-sulfonyldibenzoate water/boric acid in two tetrapropylammonium inclusion compounds

Two novel inclusion compounds of 4,4'-sulfonyldibenzoate anions and tetrapropylammonium cations with different ancillary molecules of water and boric acid, namely bis(tetrapropylammonium) 4,4'-sulfonyldibenzoate dihydrate, 2C₁₂H₂₈N⁺·C₁₄H₈O₆S^2-·H₂O (1), and bis(tetrapropylammonium) 4,4'-sulfonyldibenzoate bis(boric acid), 2C₁₂H₂₈N⁺·C₁₄H₈O₆S^2-·2H₃BO₃ (2), were prepared and characterized using single-crystal X-ray diffraction. In the two salts, the host 4,4'-sulfonyldibenzoic acid molecules, which are converted to the corresponding anions under basic conditions, can be regarded as proton acceptors which link different proton donors of the ancillary molecules of water or boric acid. In this way, an isolated hydrogen-bonded tetramer is constructed in salt 1 and a ribbon is constructed in salt 2. The tetramers and ribbons are then packed in a repeating manner to generate various host frameworks, and the tetrapropylammonium guest counter-ions are contained in the cavities of the host lattices to give the final stable crystal structures. In these two salts, although the host anion and guest cation are the same, the difference in the ancillary small molecules results in different structures, indicating the significance of ancillary molecules in the formation of crystal structures.

Crystal structure of trimethylammonium 4-((4-carboxyphenyl)sulfonyl)benzoate, C17H19NO6S

C17H19NO6S, monoclinic, C2/c (no. 15), a = 20.868(3) Å, b = 11.6189(15) Å, c = 15.0133(19) Å, β = 101.344(7)°, V = 3569.1(8) Å3, Z = 8, R gt(F) = 0.0510, wR ref(F 2) = 0.1714, T = 296(2) K.

The interaction of Mozobil™ with carboxylates

Mozobil(™) (1,1'-[1,4-phenylenebis(methylene)]bis[1,4,8,11-tetraazacyclotetradecane], 1, also known as JM3100 and AMD 3100) is a specific antagonist of the chemokine coreceptor CXCR4 and favours the mobilisation from the bone marrow of stem cells, which can be used for autologous transplantation. It is believed that the interaction, of both hydrogen bonding and electrostatic nature, involves a partly protonated form of Mozobil(™), LHn(n+) and the COO(-) groups of Asp(171) and Asp(262) residues protruding from the walls of the pocket of the membrane protein CXCR4. We have investigated, through potentiometric titrations in 0.1 M NaNO3 at 25 °C, the interaction equilibria between 1 (L) and linear dicarboxylates A(2-). These studies have demonstrated that the main equilibrium takes place: LH5(5+) + A(2-)⇄ [LH5···A](3+), and that the most stable [LH5···A](3+) complex forms for A(2-) = diphenyl-4,4'-dicarboxylate, whose length matches that of LH5(5+). (1)H NMR titration experiments have shown that in the 7-10 pH interval, LH3(3+), LH2(2+) and LH(+) forms establish π-π interactions with diphenyl-4,4'-dicarboxylate, according to a topological arrangement which excludes the formation of H-bonds. It is finally suggested that, in the pocket of the CXCR4 membrane protein, Mozobil(™) operates as a pentammonium cation, which establishes with carboxylate groups of Asp(171) and Asp(262) strong interactions of hydrogen bonding and electrostatic nature.