Related Experiment Video
Updated: Jun 5, 2025

Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks
Published on: February 10, 2023
Tuning of a Hydrogen-Bonded Organic Framework by Liquid-Assisted Mechanosynthesis between Trans-Aconitic Acid and
Diptajyoti Gogoi1, Toshiyuki Sasaki2, Nabadeep Kalita1
1Department of Chemistry, Gauhati University, Guwahati, 781014, Assam, India.
Abstract:
Cocrystallization of trans-aconitic acid (TACA) and isonicotinamide (INA) using liquid assisted mechanochemical grinding results in a unique supramolecular hydrogen-bonded organic framework (HOF) system encapsulating various organic solvents (liquid guest) with the formation of channel inclusion compounds. Dimension and shape of the framework is dependent on the solvent used during liquid assisted grinding (LAG). Although crystal structure of the cocrystal (TACA) ⋅ (INA)2 ⋅ (H2O)@(INA)0.5 has been determined by Single Crystal X-ray diffraction (SCXRD), crystal structures of 3 cocrystal HOFs were determined by microcrystal electron diffraction (MicroED) and synchrotron X-ray diffraction due to lack of suitable single crystal. PXRD analysis confirms isostructurality of various host-guest systems; whereas guest incorporation as well as stability of the HOFs were further confirmed using thermogravimetric analysis. This study demonstrates that the framework of HOFs can be tuned by varying solvent molecules used during LAG.
Related Concept Videos
Amides to Carboxylic Acids: Hydrolysis
Acid-catalyzed hydrolysis:
Hydrolysis of amides under acidic conditions yields carboxylic acids. Since the reaction occurs slowly, hydrolysis requires the conditions of heat.
The mechanism begins with the protonation of the carbonyl oxygen by the acid catalyst. The protonation makes the amide carbonyl carbon more...
Nitriles to Carboxylic Acids: Hydrolysis
Acid Halides to Amides: Aminolysis
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
Alkynes to Aldehydes and Ketones: Acid-Catalyzed Hydration
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.
Preparation of Carboxylic Acids: Hydrolysis of Nitriles
Acidity of 1-Alkynes
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.

