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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
4-Chloro-2-[(E)-(4-nitro-phen-yl)diazenyl]phenol.
Leonid A Aslanov1, Ksenia A Paseshnichenko, Alexandr V Yatsenko
1Department of Chemistry, Moscow State University, 119992 Moscow, Russian Federation.
Summary
Density functional theory (DFT) calculations confirm that the title compound exists in the azo form in both crystalline and solution states. Molecular structure analysis reveals a nearly planar configuration with an intramolecular hydrogen bond.
Area of Science:
- Crystallography
- Computational Chemistry
- Organic Chemistry
Background:
- Understanding the structural and electronic properties of organic compounds is crucial in chemistry.
- Azo compounds are a significant class of organic molecules with diverse applications.
- Computational methods like DFT provide valuable insights into molecular behavior.
Purpose of the Study:
- To determine the predominant tautomeric form of the title compound (C12H8ClN3O3).
- To elucidate the molecular geometry and crystal packing of the compound.
- To investigate the presence and role of intramolecular hydrogen bonding.
Main Methods:
- Density Functional Theory (DFT) calculations were employed to predict the stable form.
- X-ray crystallography was used to analyze the solid-state structure.
- Analysis of bond angles, dihedral angles, and intermolecular distances provided structural details.
Main Results:
- The study confirmed the azo tautomer as the stable form in both crystalline and solution states.
- The molecule exhibits a near-planar geometry with a dihedral angle of 1.83° between rings.
- A slight twist of 13.4° was observed for the nitro group relative to the benzene ring.
- Translationally related molecules form stacks with an inter-planar distance of 3.400 Å.
- An intramolecular hydrogen bond was identified between the hydroxy group and the azo nitrogen atom.
Conclusions:
- The title compound predominantly exists in the azo form.
- The molecular structure is characterized by near planarity and specific torsional angles.
- Crystal packing involves molecular stacking, and intramolecular hydrogen bonding influences the molecular conformation.
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