16551-56-7Relevant academic research and scientific papers
Synthesis, structure and Hirshfeld surface analysis of a series of novel low melting salts without alkyl groups
Duan, Hai-Bao,Shi, Jian-Han,Yu, Shan-Shan,Zhang, Hui,Zhao, Hai-Rong
, p. 8150 - 8158 (2021/12/08)
Eight ion-pair compounds, [1-APy]I3 (1), [o-FBz-1-APy]I3 (2), [o-ClBz-1-APy]I3 (3), [o-BrBz-1-APy]I3 (4), [m-FBz-1-APy]I3 (5), [m-ClBz-1-APy]I3 (6), [m-BrBz-1-APy]I3 (7) and [m-IBz-1-APy]I3 (8), were synthesized and characterized structurally. The melting point of 1, 2 and 5-8 is below 90 °C and hence these compounds can be used as ionic liquids. A common characteristic of the crystal structures of 1-8 is that the inorganic components form a linear I3- anion and the non-planar Schiff base cations surround the anion to form molecular stacks. There exist H?I hydrogen bond contacts between the cations and I3- anion in the eight compounds, and H?H interactions are the main force between the cations. The melting point of crystal 1 is the lowest with 64 °C among the eight compounds. 3 and 4 show higher Tm, ΔHfus and ΔSfus values. The substituent group of the Schiff base cation in the meta-position can also decrease the melting point of the compounds. In addition, Hirshfeld surface analysis was used to understand the intricacies of interactions occurring in the eight compounds, and the relationship between the melting point and the weak interaction was discussed. This journal is
Characteristic coloration in formation of N-1-pyridino amidate and enhancing effect of benzaldehydes
Morita,Nagano,Hirobe
, p. 2121 - 2124 (2007/10/02)
N-Aminopyridinium iodide (NAPI) turned a bluish purple color upon the addition of NaOH. The NMR spectral data of the NAPI-NaOH system indicate that N-1-pyridinio amidate (NPA) is the species responsible for the coloration, which is probably due to intramolecular charge transfer transition. The intensity of the coloration increased remarkably with addition of benzaldehyde derivatives, especially p-nitrobenzaldehyde, to the NAPI-NaOH system. NAPI reacted with the benzaldehyde derivatives to form the corresponding Schiff bases. The mechanism of the coloration in the NAPI-NaOH-benzaldehyde derivative system is proposed to involve the formation of betaines, which can also be formed by adding NaOH to the isolated Schiff bases. Furthermore, there was a good correlation between the enhancing effects on the coloration and the redox potentials of the benzaldehyde derivatives. This indicates that benzaldehyde derivatives with an electron-withdrawing substituent group can enhance the coloration intensity much more effectively.
