Structure-Making with 3,5-Dinitrosalicylic Acid. II. The Proton-Transfer Compounds of 3,5-Dinitrosalicylic Acid with the Monocyclic Heteroaromatic Amines

Abstract

The crystal structures of the proton-transfer compounds of 3,5-dinitrosalicylic acid (dnsa) with a series of common monocyclic hetero-aromatic amines (pyridine, 4-cyanopyridine, pyridine-4-carboxylic acid, 2,6-diaminopyridine and 2-aminopyrimidine) have been determined and the hydrogen-bonding associations in each analyzed. The compounds are the adduct (C 5 H 6 N) + (dnsa) -

5-Nitrosalicylic Acid and its Proton-Transfer Compounds with Aliphatic Lewis Bases

“…This is also similar to the dnsa series where the maximum deviation from planarity for this torsion angle is 19.6 o in the compound with quinaldic acid [4] but is more typically <10 o .However, the torsion angle variation for the more associative nitro substituent at C3 in the set of dnsa compounds is much greater with a maximum value of 25.5 o in the compound with pyridine compound [3] This is considered as being due to the absence in 5-nsa of the second nitro group at C3. Because of this absence, the common proximal-group interactions involving carboxyl, phenol and nitro oxygen acceptors, which in dnsa has resulted in the structural characterization of 36 proton-transfer compounds, [1][2][3][4]16] cannot occur. As with the dnsa compounds there are, in addition, fewer extending interactions involving the 5-nitro oxygen acceptors while the nitro group itself shows a lesser tendency to become a more flexible proton acceptor through rotation of the oxygen atoms out of the plane of the parent ring.…”

“…However, the quality of the crystalline proton-transfer products obtained with 5-nsa is poor by comparison so that the description of the modes of interaction of Lewis base cations with 5-nsa anions is negligible compared to those with dnsa where 36 have been crystallographically characterized. [1][2][3][4] The only reported proton-transfer structures of 5-nsa are with 3-amino-1H-1,2,4-triazole (3-at), [(3-at) + (5-nsa) -] [5] and with 8-aminoquinoline (8-aq), [(8-aq) + (5-nsa) -]. [6] We have also reported the preparation of the 1:1 proton-transfer compounds with 8-hydroxyquinoline [7] and creatinine [8] but poor crystal quality precluded their determination by X-ray methods.…”

“…[2] Other Lewis bases which were previously found to give good crystalline materials with dnsa, e.g. ammonia and a number of primary aliphatic amines, [2] as well as the hetero-aromatic examples (pyridine, [3] quinoline, [4] and the bifunctional polycyclic bases 1,10-phenanthroline [4] and 2,2'-bipyridine [4] ) were found to give immediate precipitation of unmanageable products on reaction with 5-nsa so that the set reported here represents the rare isolation of crystalline products suitable for X-ray analysis.…”

Crystal structure of tetraethylammonium 3,5-dinitrosalicylate, C15H23N3O7

“…3,5-Dinitrosalicylic acid (2-hydroxy-3,5-dinitrobenzoic acid) is used to detect reducing substances in urine, for quantifying carbohydrate levels in blood and in assays of α-amylase. There are several crystal structure reports on 3,5-dinitrosalicylate with a variety of anions like 2-methoxyanilinium [1], 4-aminobenzenesulfonamide [2], 4-cyanopyridinium [3], ammonium [4], diethylammonium [5], 1-phenylethylaminium [6] and 3-(1H-imidazol-1-yl)propan-1-aminium [7] and some cases where 3,5-dinitrosalicylate is coordinated to copper(II) in a bidentate fashion [8,9] but no structure reports the tetraethylammonium salt. …”

New oxidation–reduction polymers on the basis of pyridine nitriles

“…At the present time a number of works devoted to the creation of polymers on the basis of cyanopyridines and their derivatives have been published [5,6].…”