Related Experiment Video
Updated: Jun 10, 2025
Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Intermolecular Hydrogen-Bonded Interactions of Oxalic Acid Conformers with Sulfuric Acid and Ammonia
Eduardo da Silva Carvalho1, Angsula Ghosh1, Puspitapallab Chaudhuri1
1Department of Materials Physics, Federal University of Amazonas, Manaus, AM 69080-900, Brazil.
Abstract:
Oxalic acid is one of the simplest naturally occurring dicarboxylic acids that is abundantly found in the atmosphere, and it has several stable structural conformers. Hydrogen-bonded interactions of oxalic acid with other atmospheric molecules are important, as they might influence the chemical composition of the atmosphere, thereby impacting atmospheric chemistry and environmental processes. In this work, we used density functional calculations with the M06-2X/6-311++G(3df,3pd) model to examine the interaction of five oxalic acid conformers with sulfuric acid and ammonia-two widely recognized atmospheric nucleation precursor molecules-with the aim of observing the hydrogen-bonding characteristics of the conformers individually. An extensive and systematic quantum-chemical calculation has been conducted to analyze the structural, thermodynamical, electrical, and spectroscopic characteristics of several binary and ternary clusters mediated by five oxalic acid conformers. Our analysis of the electronic-binding energies and free energy changes associated with the formation of the clusters at ambient temperature reveals that multiple conformations of oxalic acid have the potential to engage in stable cluster formation in the atmosphere. In fact, the highest energy oxalic acid conformer exhibits the lowest bonding free energy in most cases. According to our calculations, clusters of oxalic acid with sulfuric acid demonstrate greater thermodynamic stability, a higher probability of formation, and more intense light scattering compared to clusters with ammonia. Furthermore, the analysis of successive cluster formation reveals that clusters formed between sulfuric and oxalic acids are more likely to grow spontaneously than those formed between ammonia and oxalic acid.
Related Concept Videos
03:05Acid Strength and Molecular Structure
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with...
02:29Relative Strengths of Conjugate Acid-Base Pairs
01:28Structures of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the...
01:04Hydrogen Bonds
01:28Amides 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...
01:20Titration of a Weak Base with a Strong Acid
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...