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Updated: Jun 1, 2026
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Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
1-Hydroxy-4-aza-1-azoniabicyclo[2.2.2]octane picrate
1Ordered Matter Science Research Center, College of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People's Republic of China.
Summary
The crystal structure reveals a three-dimensional network formed by hydrogen bonds between cations and anions. Nitro groups on the picrate anion exhibit disorder, with oxygen atoms occupying two positions.
Area of Science:
- Crystallography
- Supramolecular Chemistry
- Materials Science
Background:
- Understanding the intermolecular interactions in crystalline solids is crucial for predicting material properties.
- Picrate salts are known for their energetic properties and diverse crystal structures.
- Hydrogen bonding plays a significant role in the self-assembly of molecular structures.
Purpose of the Study:
- To elucidate the crystal structure of the title compound, C(6)H(13)N(2)O(+)·C(6)H(2)N(3)O(7) (-).
- To investigate the nature and extent of hydrogen bonding interactions within the crystal lattice.
- To characterize the structural features, including any disorder, present in the compound.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the three-dimensional crystal structure.
- Analysis of the crystal structure involved identifying hydrogen bond donors and acceptors.
- Disorder in specific atomic positions was modeled and refined.
Main Results:
- The crystal structure consists of discrete cations (C(6)H(13)N(2)O(+)) and anions (C(6)H(2)N(3)O(7) (-)).
- A robust three-dimensional network is formed through a combination of O-H⋯O, C-H⋯O, and C-H⋯N hydrogen bonds.
- The oxygen atoms of a nitro group within the picrate anion were found to be disordered over two equally occupied positions.
Conclusions:
- The hydrogen bonding network dictates the overall supramolecular architecture of the compound.
- The observed disorder in the picrate anion's nitro group is a key structural characteristic.
- This structural information provides a foundation for understanding the compound's physical and chemical behavior.
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01:11Nomenclature of Carboxylic Acid Derivatives: Amides and Nitriles
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The IUPAC and common names of amides are derived from the parent carboxylic acid, by replacing the suffix “oic acid” and “ic acid,” respectively, with “amide.” In the following example, the IUPAC name ethanamide is derived from ethanoic acid, and the common name, acetamide, is obtained from acetic acid.
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IUPAC names of carboxylic acids are systematically derived following a few rules discussed below.
For acyclic saturated monocarboxylic acids, the longest hydrocarbon chain containing the –COOH carbon is identified as the parent chain. Then, the last -e of the parent hydrocarbon name is replaced with a suffix -oic acid.
For acyclic saturated monocarboxylic acids, the longest hydrocarbon chain containing the –COOH carbon is identified as the parent chain. Then, the last -e of the parent hydrocarbon name is replaced with a suffix -oic acid.
01:09IUPAC Nomenclature of Ketones
Like aldehydes, ketones are named using IUPAC rules; in this case, by replacing “e” in the name of the longest hydrocarbon chain with “one.” In acyclic ketones, the ketonic carbon is given the lowest locant value. For instance, as shown below, a simple five-carbon ketone is named pentan-2-one, instead of pentan-4-one. IUPAC rules also allow the placing of the locant value before the parent name to give an alternate name, 2-pentanone.
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