Synthesis, Characterization, and the Study of Thermal Behavior and Catalytic Activity of a Halogen-free Dicationic Ionic Liquid
Document Type
Article
Publication Date
8-1-2024
Abstract
4,4'-Trimethylenedipiperidin-N,N'-diium diacetate was obtained as a cream-like liquid with a pale yellow color. Its ionic structure was demonstrated by different spectroscopic techniques, and its thermal behavior was also studied by TGA/DTA and DSC techniques to record its phase transitions and thermal stability and compare those with another analog, i.e., 1H,4H-piperazine-N,N'-diium diacetate. Due to the existence of monoprotic Bronsted base and conjugate acid of TMDP in the new ionic liquid, it can act as a promising hydrogen bond catalyst. Thus, the Knoevenagel condensation of various substituted benzaldehydes with malononitrile was investigated using the new ionic liquid in ethanol. Ethanol acts as a reaction medium and crystallization solvent, and pure products were obtained directly from ethanol with no costly separation and purification. The residue solution was employed in the next run without concentration or activation. Furthermore, the model reaction was carried out on a large scale using the current catalytic process, affording a conversion of 100% and a high yield of the crystalline product even after ten consecutive runs. Energy efficiency, cost- and time-saving, and waste prevention demonstrate the newly developed metal- and halogen-free catalytic system as a more sustainable catalytic process for preparing the substituted arylidene malononitriles on the laboratory and industrial scale.
Keywords
Ionic Liquid, Homogeneous Catalysis, Sustainable Chemistry, Condensation, Waste Prevention
Divisions
nanotechnology
Funders
International Collaboration Grant, Universiti Malaya, Malaysia
Publication Title
Catalysis Letters
Volume
154
Issue
8
Publisher
Springer
Publisher Location
ONE NEW YORK PLAZA, SUITE 4600, NEW YORK, NY, UNITED STATES