p-Substituted benzamidinium carboxylates

Abstract

Various p-substituted benzamidinium formates (I), acetates (II), trifluoroacetates (III) and pyruvates (IV) were prepared and the nature of the amidinium-carboxylate interactions were examined by 1H and 13C NMR spectra. The spectroscopic data are consistent with the presumption that the carboxylic part is only slightly influenced by the diverse substitution of the aromatic benzamidinium ring.

Crystalline Films of Interdigitated Structures Formed via Amidinium−Carboxylate Interactions at the Air−Water Interface

“…However, the X-ray reflectivity studies presented here did not indicate binding of the solute molecules to the monolayer film. It has been established that in aqueous solution there is no observed binding between the carboxylate and amidinium moieties . On the other hand we might have expected binding to occur at the air−solution interface by virtue of cooperative hydrogen bonding as indeed observed in the 3D crystal structure of the analogous interdigitated system.…”

“…In the present study, we take advantage of electrostatic interactions between amidinium and carboxylic acid functions (Scheme ) as the starting building blocks. These structures are of importance in biological systems containing arginine-active sites. − Simple chemical systems based on these interactions were extensively studied in aqueous and in nonaqueous solutions. − Strong hydrogen bonds of the type N−H···O−C between amidinium (or guanidinium) and carboxylic moieties existing in nonpolar solutions were employed for the design of supramolecular architectures , and in artificial self-replicating systems that mimic natural molecular self-replication and might shed light on the origin of evolution of living systems. , The strong electrostatic interactions between carboxylate and amidinium moieties would thus appear suitable to guarantee the formation of a mixed monolayer of the - A - B - A - B -type, where A is the amphiphilic acid moiety and B the water-soluble base (or vice versa). The hydrocarbon chains bound to the A headgroups in the extended -A - B - A - B -type rows are poorly packed so that such a monolayer should be amorphous but, upon compression, transform into a crystalline interdigitated multilayer (Scheme , right and left).…”

Hydrogen Bonding Network of 4‐Amidiniumpyridine Acetate and PtIIbis(triphenylphosphine) Complexes with 4‐Amidine­pyridine

“…4‐Amidiniumpyridine acetate, ( 1· H)AcO was synthesized by a slight modification of previously described methods,13,24 i.e. condensation of 4‐cyanopyridine with methanol, and subsequent substitution with ammonia.…”

“…4‐Pyridineamidinium Acetate (1·H)AcO: 13,24 Solid lithium methoxide (0.0751 g, 2 mmol) was added to a solution of 4‐cyanopyridine (1.0200 g, 10 mmol) in anhydrous methanol (10 mL). After 1 d whilst stirring at room temperature, lithium methoxide was quenched by the addition of glacial acetic acid (120 μL, 2 mmol), followed by ammonium acetate (0.7536 g, 10 mmol).…”

An ab initio study of the unimolecular decomposition mechanism of formamidine. 4‐31G Characterization of potential energy hypersurface

“…Nevertheless, the importance of arginine in enzymatic processes is much more general and there are number of enzymes where it is responsible for the substrate fixation and hence, plays a crucial role in the mechanism (for review articles see, e.g., [3]). In our previous synthetic [4] as well as quantum chemical [5] and X-ray [6] communications, we have studied simple amidinium carboxylates as valuable models of this interaction.…”