Evaluation of Halogenopyridinium Cations as Halogen Bond Donors was written by Fotovic, Luka;Bedekovic, Nikola;Stilinovic, Vladimir. And the article was included in Crystal Growth & Design in 2021.Reference of 626-64-2 This article mentions the following:
We have performed a database survey and a structural and computational study of the potential and the limitations of halogenopyridinium cations as halogen bond donors. The database survey demonstrated that adding a pos. charge on a halogenopyridine ring increases the probability that the halogen atom will participate in a halogen bond, although for chloropyridines it remains below 60%. Crystal structures of both protonated and N-methylated monohalogenated pyridinium cations revealed that the iodo- and bromopyridinium cations always form halogen-bonding contacts with the iodide anions shorter than the sum of the vdW radii, while chloropyridinium cations mostly participate in longer contacts or fail to form halogen bonds. Although a DFT study of the electrostatic potential has shown that both protonation and N-methylation of halogenopyridines leads to a considerable increase in the ESP of the halogen 锜?hole, it is generally not the most pos. site on the cation, allowing for alternate binding sites. In the experiment, the researchers used many compounds, for example, Pyridin-4-ol (cas: 626-64-2Reference of 626-64-2).
Pyridin-4-ol (cas: 626-64-2) belongs to pyridine derivatives. Pyridine has a conjugated system of six 锜?electrons that are delocalized over the ring. The molecule is planar and, thus, follows the H鐪塩kel criteria for aromatic systems. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Reference of 626-64-2