In 2019,Physical Chemistry Chemical Physics included an article by Iribarren, Inigo; Montero-Campillo, M. Merced; Alkorta, Ibon; Elguero, Jose; Quinonero, David. SDS of cas: 1692-25-7. The article was titled 《Cations brought together by hydrogen bonds: the protonated pyridine-boronic acid dimer explained》. The information in the text is summarized as follows:
According to the Cambridge Structural Database, protonated pyridine-boronic acid dimers exist in the solid phase, apparently defying repulsive coulombic forces. In order to understand why these cation-cation systems are stable, we carried out M06-2X/6-311++G(3df,2pd) electronic structure calculations and used a set of computational tools (energy partitioning, topol. of the electron d. and elec. field maps). The behavior of the charged dimers was compared with the corresponding neutral systems, and the effect of counterions (Br- and BF4-) and the solvent (PCM model) on the binding energies has been considered. In the gas-phase, the charged dimers present pos. binding energies but are local min., with a barrier (16-19 kJ mol-1) preventing dissociation Once the environment is included via solvent effects or counterions, the binding energies become neg.; remarkably, the strength of the interaction is very similar in both neutral and charged systems when a polar solvent is considered. Essentially, all methods used evidence that the intermol. region where the HBs take place is very similar for both neutral and charged dimers. The energy partitioning explains that repulsion and electrostatic terms are compensated by the desolvation and exchange terms in polar solvents, thus giving stability to the charged dimer.Pyridin-3-ylboronic acid(cas: 1692-25-7SDS of cas: 1692-25-7) was used in this study.
Pyridin-3-ylboronic acid(cas: 1692-25-7) belongs to pyridine. Pyridine’s structure is isoelectronic with that of benzene, but its properties are quite different. Pyridine is completely miscible with water, whereas benzene is only slightly soluble. Like all hydrocarbons, benzene is neutral (in the acid–base sense), but because of its nitrogen atom, pyridine is a weak base.SDS of cas: 1692-25-7