Dicationic pyridinium salts as new organic ionics: Changes in solid-state phases and thermal/electrochemical properties was written by Shin, Jong Chan;Lim, Seok-In;Jeong, Kwang-Un;Shim, Joong Pyo;Lee, Minjae. And the article was included in Journal of Industrial and Engineering Chemistry (Amsterdam, Netherlands) in 2022.Category: pyridine-derivatives This article mentions the following:
To explore a new family of organic ionic materials, a series of 婵?闂?bis[N,N’-(4-alkylpyridinium)]alkane salts I [R = Me, Et, n-hexyl, etc.; n = 2,3,4] combined with iodide (I–), tetrafluoroborate (BF4–), and bis(trifluoromethanesulfonyl)imide (Tf2N–) anions and alkylene bridges of different lengths were synthesized. From 1H NMR chem. shift changes, the proton acidity of at the bis-pyridinium cations could be estimated for different anions. All the synthesized I– and BF-4 salts had one or multiple solid-solid phase transitions, which were typical features of plastic and liquid crystals. The I– or BF-4 salts with large values (>90 J mol-1 K-1) of total entropy changes in solid-solid phase transitions had a very soft crystalline phase. Combined with polarized microscope images and wide-angle X-ray diffraction spectra, 1,2-bis[N,N’-(4-n-dodecylpyridinium)]ethane 2BF4– might be a true plastic crystal. The thermal properties of the bis-pyridinium Tf2N– salts were quite different; they showed only a melting transition and are thermally more stable than those of I– and BF4–. The electrochem. window of the bis-pyridinium BF4– and Tf2N– salts was stable up to 4.3 V (vs. Li/Li+). In the experiment, the researchers used many compounds, for example, 4-Hexylpyridine (cas: 27876-24-0Category: pyridine-derivatives).
4-Hexylpyridine (cas: 27876-24-0) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Category: pyridine-derivatives