Related Experiment Video
Updated: May 21, 2026
06:34
Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides (CHIPS)
Published on: June 20, 2014
Oxalic acid-pyridine-4-carbonitrile (1/2)
1College of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, People's Republic of China.
Summary
The crystal structure of pyridine-4-carbonitrile and oxalic acid reveals stacked molecular arrangements. Strong hydrogen bonds form between oxalic acid and pyridine-4-carbonitrile molecules, influencing crystal packing.
Area of Science:
- Crystallography
- Supramolecular Chemistry
- Materials Science
Background:
- Understanding molecular interactions is crucial for designing new materials.
- Crystal engineering aims to control the solid-state structure and properties of compounds.
- Pyridine-4-carbonitrile and oxalic acid are relevant organic building blocks.
Purpose of the Study:
- To elucidate the crystal structure of the co-crystal formed by pyridine-4-carbonitrile and oxalic acid.
- To investigate the intermolecular interactions governing the crystal packing.
- To characterize the hydrogen bonding network and stacking motifs.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the three-dimensional structure.
- Analysis of bond lengths, angles, and intermolecular distances was performed.
- Hydrogen bonding and other non-covalent interactions were identified and quantified.
Main Results:
- The crystal structure consists of oxalic acid and pyridine-4-carbonitrile molecules arranged in stacks.
- Oxalic acid molecules are located about an inversion center.
- Strong O-H⋯N hydrogen bonds and weaker C-H⋯O interactions mediate the crystal assembly, with inter-planar distances of 3.183(1) and 3.331(2) Å.
Conclusions:
- The co-crystal formation is driven by a combination of strong hydrogen bonding and π-π stacking interactions.
- The planar pyridine ring and the oxalic acid molecule contribute to the observed stacking.
- This study provides insights into the supramolecular assembly of organic molecules, relevant for crystal engineering.
Related Concept Videos
01:08Nitriles to Carboxylic Acids: Hydrolysis
Nitriles undergo acid-catalyzed hydrolysis or base-catalyzed hydrolysis to form a carboxylic acid. These reactions proceed via an amide intermediate.
01:01Acid Halides to Carboxylic Acids: Hydrolysis
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
01:28Structures of Carboxylic Acid Derivatives
Structure 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 unhybridized p...
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 unhybridized p...
01:19Preparation of Carboxylic Acids: Hydrolysis of Nitriles
Nitriles (R–CN) can be converted into carboxylic acids (R–COOH) upon treatment with aqueous acids, i.e., upon hydrolysis of nitriles. Under base-catalyzed conditions, carboxylate anions (R–COO−) are formed.
02:01Alkynes to Carboxylic Acids: Oxidative Cleavage
Alkynes undergo oxidative cleavage in the presence of oxidizing reagents like potassium permanganate and ozone. The triple bond — one σ bond and two π bonds — is completely cleaved, and the alkyne is oxidized to carboxylic acids. When warm and basic aqueous potassium permanganate is used as an oxidizing agent, alkynes are first converted to carboxylate salts via an unstable α-diketone intermediate. Further, a mild acid treatment protonates the carboxylate anions generating free carboxylic acid...
01:28Amides to Carboxylic Acids: Hydrolysis
Amides can undergo either acid-catalyzed hydrolysis or base-promoted hydrolysis through a typical nucleophilic acyl substitution. Each hydrolysis requires severe conditions.
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...
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...