Formation of one-dimensional water inside an organic solid: supramolecular architectures derived by the interaction of aminobenzoic acids with nitrogen bases and H₂SO₄

Abstract

Three different organic supramolecular architectures derived from 2- and 3-aminobenzoic acids are reported. 3-Aminobenzoic acid (3-ABA-H) forms complexes with 2-aminopyridine (2-AP) and 1,4-diazabicyclo[2,2,2]octane (DABCO) to yield [(3-ABA)(2-AP-H)] (1) and [(3-ABA)(DABCO-H)(H₂O)₂] (2), respectively. 2-Aminobenzoic acid (2-ABA-H), on the other hand, interacts with sulfuric acid in the presence of V₂O₅ to yield [(2-ABA-H₂)₄(HSO₄)₂(SO₄)(H₂O)] (3). Compounds 1-3 have been obtained as single crystals and characterized by elemental analysis, IR and ¹H NMR spectroscopy, and single-crystal X-ray diffraction techniques. Compound 1 crystallizes in the monoclinic space group P2₁/c [a = 9.6455(5) Å, b = 10.9229(7) Å, c = 11.976(2) Å, β = 112.932(7)°, R1 = 0.0363]. It is an infinite two-dimensional layered polymer in which the carboxylic acid hydrogen is transferred to the pyridine nitrogen. Compound 2 crystallizes in the monoclinic space group Cc [a = 14.2950(9), b = 11.7660(7), c = 9.813(1) Å, β= 116.214(7)°, R1 = 0.0492], in which one of the DABCO nitrogens is protonated by accepting the proton of the carboxylic acid. The two water molecules present in the asymmetric part of the unit cell of 2 form an unusual assembly of water to form a one-dimensional polymeric chain through hydrogen bonding. Compound 3 crystallizes in the triclinic space group P↑ [a = 7.470(1), b = 11.128(1), c = 22.552(2) Å, a = 85.075(7)°, β = 88.712(9)°, γ = 72.509(8)°, R1 = 0.0573]. A number of N-H···O, O-H···O, and/or N-H···N hydrogen bonds are prevalent in the structures of 1-3, resulting in the formation a two- or three-dimensional supramolecular architecture in these compounds.