Structure-Making with 3,5-Dimitrosalicylic Acid. I. The Proton Transfer Compounds of 3,5-Dinitrosalicylic Acid with a Series of Aliphatic Amines

2002 ◽  
Vol 55 (5) ◽  
pp. 349 ◽  
Author(s):  
G. Smith ◽  
U. D. Wermuth ◽  
P. C. Healy ◽  
R. C. Bott ◽  
J. M. White
Keyword(s):  
Hydrogen Bonding ◽  
Proton Transfer ◽  
Lewis Base ◽  
Aliphatic Amines ◽  
Tertiary Amines ◽  
Carboxylate Oxygen ◽  
Phenolic Oxygen ◽  
Phenolic Group ◽  
Intramolecular Hydrogen ◽  
Proton Transfer Compounds

The crystal structures of the proton-transfer compounds of 3,5-dinitrosalicylic acid (dnsa) with ammonia (two polymorphs) and a series of common aliphatic amines (methylamine, triethylamine, hexamethylenetetramine and ethylenediamine) have been determined and the hydrogen-bonding associations in each analysed. The compounds are [(NH4)+(dnsa)-] (1A, 1B), [(CH3NH3)+(dnsa)-] (2), [{(C2H5)3NH}+(dnsa)-] (3), [(C6H12 N4H)+(dnsa)-] (4) and [{(CH2 NH3) 2}2+(dnsa)2-�H2O] (5). It is of interest that with hydrate (5) the phenolic proton of dnsa is also lost on reaction, giving a rare dianionic species. In all compounds, protonation of the amino group of the Lewis base occurs, with subsequent hydrogen bonding via this and other hydrogens variously to the carboxylic, nitro and phenolic oxygens of dnsa, and in the case of (5), the lattice water. The result is the formation of simple linear associations with the tertiary amines, or network polymers with the less-substituted examples. Short intramolecular hydrogen bonds between the phenolic group and the carboxylate group are found in all compounds except (5), with the proton localized on the carboxylate oxygen rather than on the phenolic oxygen, but in the case of (3), delocalized within the hydrogen bond.

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

2005 ◽  
Vol 58 (1) ◽  
pp. 47 ◽  
Author(s):  
Graham Smith ◽  
Andy W. Hartono ◽  
Urs D. Wermuth ◽  
Peter C. Healy ◽  
Jonathan M. White ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Lewis Base ◽  
Unusual Structure ◽  
Lewis Bases ◽  
Carboxylate Oxygen ◽  
Hydrogen Bonding Interactions ◽  
Polymer Compound ◽  
Proton Transfer Compounds ◽  
Centrosymmetric Dimers

The crystal structures of the proton-transfer compounds of 5-nitrosalicylic acid (5-nsa) with morpholine (morph), hexamethylenetetramine (hmt), and ethylenediamine (en) have been determined and their solid-state packing structures described. The compounds are [(morph)+(5-nsa)–] 1, [(hmt)+(5-nsa)–·H2O] 2, and [(en)2+2(5-nsa)–·H2O] 3. In all compounds, protonation of the hetero-nitrogen of the Lewis base occurs. With 1, the 5-nsa anions and the morpholine cations lie, respectively, in or across crystallographic mirror planes and are linked within the planes by hydrogen-bonding interactions through the aminium group and the carboxylic and phenolic oxygens of the anionic 5-nsa species giving a two-dimensional sheet polymer. Compound 2 is an unusual structure with the planar 5-nsa anions lying within pseudo mirror planes and cyclically linked by duplex water bridges through a single carboxylate oxygen into centrosymmetric dimers. The hmt cation molecules are disordered across the pseudo mirror and are strongly linked by N+–H···O hydrogen bonds only to the water molecules with peripheral weak hmt C–H···O hydrogen bonds extending the dimer within and between the dimer planes. Compound 3 is a network polymer comprised of the 5-nsa anions, the en dianions, and the water molecule in an extensive hydrogen-bonded structure.

scholarly journals 3,5-Dinitrosalicylic Acid in Molecular Assembly. III. Proton-Transfer Compounds of 3,5-Dinitrosalicylic Acid with Polycyclic Aromatic and Heteroaromatic Amines, and Overall Series Structural Systematics

2007 ◽  
Vol 60 (4) ◽  
pp. 264 ◽  
Author(s):  
Graham Smith ◽  
Urs D. Wermuth ◽  
Peter C. Healy ◽  
Jonathan M. White
Keyword(s):  
Hydrogen Bonding ◽  
Proton Transfer ◽  
Crystal Structures ◽  
Molecular Assembly ◽  
Lewis Base ◽  
Amino Group ◽  
Π Interactions ◽  
Hydrogen Donors ◽  
Polycyclic Aromatic ◽  
Proton Transfer Compounds

The crystal structures of the 1:1 proton-transfer compounds of 3,5-dinitrosalicylic acid (dnsa) with a series of common polycyclic aromatic and heteroaromatic amines (quinoline, 1-naphthylamine, 1,2,3,4-tetrahydroquinoline, quinaldic acid, benzimidazole, 1,10-phenanthroline, and 2,2′-bipyridine) have been determined and the hydrogen-bonding associations in each analyzed. The compounds are [(C9H8N)+(dnsa)–] 1, [(C10H10N)+(dnsa)–] 2, [(C9H12N)+(dnsa)–] 3, [(C10H8NO2)+(dnsa)–] 4, [(C7H7N2)+(dnsa)–] 5, [(C12H9N2)+(dnsa)–] 6, and [(C10H9N2)+(dnsa)–] 7. In all compounds, protonation of either the substituent amino group or the hetero-N of the Lewis base occurs, with subsequent hydrogen bonding via this and other hydrogen donors variously to the carboxylate, phenate, and nitro oxygen acceptors of the dnsa anions. The result is the formation of primary N+–H···O associations which with secondary peripheral interactions, which within this set of compounds includes an increased incidence of aromatic C–H···O associations, give framework polymer structures. In three of the compounds [1, 4, and 6], cation–anion π–π interactions are also found. The completion of this series of compounds has now allowed the categorization of the molecular assembly modes in the proton-transfer compounds of 3,5-dinitrosalicylic acid.

Effect of intramolecular hydrogen bonding on the relative acidities of substituted salicylic acids in benzene solution

1967 ◽  
Vol 45 (14) ◽  
pp. 1699-1706 ◽  
Author(s):  
G. E. Dunn ◽  
Thomas L. Penner
Keyword(s):  
Hydrogen Bonding ◽  
Electronic Effect ◽  
Benzene Solution ◽  
Intramolecular Hydrogen Bonding ◽  
Acid Strength ◽  
Carboxyl Group ◽  
Hammett Equation ◽  
Phenolic Group ◽  
Intramolecular Hydrogen ◽  
Salicylic Acids

The relative acidities of fifteen 4- and 5-substituted salicylic acids were determined in benzene solution by potentiometric titration. The potentials at half neutralization (h.n.p.) relative to that of salicylic acid were considered to measure the acidities of the substituted acids relative to the parent acid. These potentials, designated by Δhnp, gave a significantly better correlation with Hammett's sigma constants in an equation of the form proposed by Jaffe, Δhnp = ρ1σ1 + ρ2σ2, than in a simple Hammett equation, Δhnp = ρ1σ1. In these equations the subscripts 1 and 2 refer to the position of a substituent relative to the carboxyl group and to the phenolic group respectively. The value of ρ2/ρ1 was found to be 0.4, indicating that the electronic effect of a substituent on the acid strength via the phenolic hydrogen-bonded path is almost half as large as the direct effect through the carboxyl group. These results, together with the fact that in aqueous solution there is very little if any transmission via the phenolic group, are discussed in terms of intramolecular hydrogen bonding of salicylic acids in benzene and in water.

Structure and Conformations of Gaba-Transaminase Inhibitors. I. Multisubstrate Analogs

1986 ◽  
Vol 39 (10) ◽  
pp. 1559
Author(s):  
PR Andrews ◽  
V Cody ◽  
MN Iskander ◽  
AI Jeffrey ◽  
MF Mackay ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Transition State ◽  
Intramolecular Hydrogen Bonding ◽  
Side Chain ◽  
Gaba Transaminase ◽  
X Ray ◽  
Potential Energy Calculations ◽  
Phenolic Oxygen ◽  
Structural Differences ◽  
Intramolecular Hydrogen

Two multisubstrate analogues of the transition state in the reaction catalysed by the enzyme GABA- transaminase (E.C. 2.6.1.19), sulfonic acid pyridoxal dervative , C10H16N2O5S (1) and carboxylic acid pyridoxal derivative, C13H18N2O4 (2), have been characterized by X-ray analyses of crystals of (1). HCl , (1).H2O and (2). HCl . In each structure, the nitrogen on the side chain is the donor in intramolecular hydrogen bonding. However, it is only in (2). HCl that this interaction is with the phenolic oxygen as postulated in the proposed transition state of the reaction catalysed by GABA- transaminase . For both structures of (1), on the other hand, this interaction is with the oxygen of the ring hydroxymethyl substituent, and results in a seven- membered ring. Conformational analysis indicates that both modes of hydrogen bonding may be present in the pyridoxal derivatives, although no quantitative assessment is possible at the MINDO/3 or MNDO levels. Simple classical potential energy calculations indicate significant structural differences between the lowest energy conformations of these compounds and the calculated transition state. However, conformations which match the key features of the transition state are also relatively low in energy.

Hydrogen bonding networks and proton transfer compounds of cobalt(II) and copper(II) with pyridine-2,5-dicarboxylate

Polyhedron ◽  
2011 ◽  
Vol 30 (6) ◽  
pp. 1012-1022 ◽  
Author(s):  
Alper Tolga Çolak ◽  
Okan Zafer Yeşilel ◽  
Gönül Pamuk ◽  
Handan Günay ◽  
Orhan Büyükgüngör
Keyword(s):  
Hydrogen Bonding ◽  
Proton Transfer ◽  
Hydrogen Bonding Networks ◽  
Proton Transfer Compounds
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