A Competitive Molecular Recognition Study: Syntheses and Analysis of Supramolecular Assemblies of 3,5‐Dihydroxybenzoic Acid and Its Bromo Derivative with Some N‐Donor Compounds

Abstract

A molecular recognition study of 3,5-dihydroxybenzoic acid (1) and its bromo derivative 4-bromo-3,5-dihydroxybenzoic acid (2) with the N-donor compounds 1,2-bis(4-pyridyl)ethene (bpyee), 1,2-bis(4-pyridyl)ethane (bpyea), and 4,4'-bipyridine (bpy) is reported. Thus, the syntheses and structural analysis of molecular adducts 1 a-1 c (1 with bpyee, bpyea, and bpy, respectively) and 2 a-2 c (2 with bpyee, bpyea, and bpy, respectively) are discussed. In all these adducts, recognition between the constituents is established through either O--H...N and/or O--H...N/C--H...O pairwise hydrogen bonds. In all the adducts both OH and COOH functional groups available on 1 and 2 interact with the N-donor compounds, except in 2 a, in which only COOH (COO-) is involved in the recognition process. The COOH moieties in 1 a, 1 b, and 2 b form only single O--H...N hydrogen bonds, whereas in 1 c and 2 c, they form pairwise O--H...N/C--H...O hydrogen bonds. In addition, subtle differences in the recognition patterns resulted in the formation of cyclic networks of different dimensions. In fact, only 1 c forms a four-molecule cyclic moiety, as was already documented in the literature for this kind of assemblies. All complexes have been characterized by single-crystal X-ray diffraction. The supramolecular architectures are quite elegant and simple, with stacking of sheets in all adducts, but a rather complex network with a threefold interpenetration pattern was found in 2 c.

Structure of seven organic salts assembled from 2,6-diaminopyridine with monocarboxylic acids, dicarboxylic acids, and tetracarboxylic acids

“…Furthermore, it is now recognized that carboxylic acids are ideal candidates for multi-component crystals since they form persistent supramolecular heterosynthons with a number of different complementary functional groups such as amine, and aromatic nitrogen etc. For instance, much has been said about the use of carboxyl and pyridyl groups in the design of supramolecular systems [8][9][10][11][12][13]. Besides the COOH group, the functional groups such as amine, halogen, NO 2 , and phenol OH groups are all good groups in forming organic solid through non-covalent interactions [14].…”

Packing incentives and a reliable N–H⋯N–pyridine synthon in co-crystallization of bipyridines with two agrochemical actives

“…In 35 practice, however, packing in crystals is influenced by an intricate combination of close packing incentives, hydrogen bonding and other interactions and therefore there is as yet no reliable way to design co-crystals. Previously, we have been investigating the polymorphism and 40 versatile solvate formation of two agrochemical actives, thiophanate-methyl (TM) 10 and thiophanate-ethyl (TE) 11 (Scheme 1), and decided now to examine co-crystallization with common co-crystal formers, namely 4,4'-bipyridine (44bp) [12][13][14][15][16][17] and 2,2'-bipyridine (22bp) 18 (Scheme 1) as pyridine solvates of TM and 45 TE are also known. Due to the success with the first bipyridines, crystallizations with the similar 1,2-bis(4-pyridyl)ethane (44bpe) (Scheme 1) were also attempted.…”

Crystal structure of hydrogen methyl ether perchlorate — 1,3-bis(4- pyridyl)propane (1:1), [C2H7O][ClO4] ·C13H14N2

“…In this regard, N,N'-donor spacer ligands such as 1,2-bis(4-pyridyl)ethane (bpa) and 1,3-bis(4-pyridyl)propane (bpp) are used in both branches of crystal engineering since, apart from its rod-like characteristics, the gauche and anti conformations which may induce supramolecular isomerism in coordination compounds. With this ligand, a large number of novel networks of ingenious design have been constructed [4][5][6][7][8][9]. In particularly, there has been much interest in the rational design and synthesis of cocrystals assemblied with bpa or bpp component [7][8][9].…”

“…With this ligand, a large number of novel networks of ingenious design have been constructed [4][5][6][7][8][9]. In particularly, there has been much interest in the rational design and synthesis of cocrystals assemblied with bpa or bpp component [7][8][9]. Besides the strong and directional O-H···Nand O-H···Ohydrogen bonds, the weak C-H···X(X=O or N) are frequently used to stabilize such organic crystals.…”