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Updated: Aug 6, 2026
05:34
Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes
Published on: December 16, 2019
BenzDB, an Exhaustive Database of Benzenoids up to Nine 6-Membered Rings
Adrien Varet1, Cyril Terrioux1, Nicolas Prcovic1
1Aix Marseille Univ , CNRS, LIS, Marseille13397, France.
Journal of Chemical Information and Modeling
|July 16, 2026
Summary
BenzDB is a new database of 8,392 neutral benzenoids, offering comprehensive structural, spectral, and magnetic data. This resource aids researchers studying polycyclic aromatic hydrocarbons (PAHs) and related materials.
Area of Science:
- Computational Chemistry
- Materials Science
- Chemical Informatics
Background:
- Polycyclic Aromatic Hydrocarbons (PAHs) are crucial in various scientific fields.
- Existing databases for PAHs are limited in scope and size.
- Neutral benzenoids represent a fundamental class of PAHs.
Purpose of the Study:
- To create an exhaustive database of neutral benzenoids.
- To provide comprehensive computational data for benzenoids.
- To facilitate research on PAH properties and applications.
Main Methods:
- Density Functional Theory (DFT) computations for property calculations.
- Generation of 8,392 neutral benzenoids up to nine hexagons.
- Inclusion of structural, graph-theoretical, vibrational, and magnetic properties.
Main Results:
- BenzDB contains extensive data on benzenoid structures and properties.
- Properties include optimized geometries, Kekulé structures, Clar covers, vibrational spectra, and NICS values.
- Comparison with existing PAH databases highlights BenzDB's comprehensiveness.
Conclusions:
- BenzDB is a valuable, accessible resource for the scientific community.
- The database supports research in areas like organic electronics and astrophysics.
- BenzDB is available via BenzAI software, Jupyter notebooks, and a REST API.
Related Concept Videos
01:37NMR Spectroscopy of Benzene Derivatives
Simple unsubstituted benzene has six aromatic protons, all chemically equivalent. Therefore, benzene exhibits only a singlet peak at δ 7.3 ppm in the 1H NMR spectrum. The observed shift is far downfield because the aromatic ring current strongly deshields the protons. Any substitution on the benzene ring makes the aromatic protons nonequivalent, and the protons split each other. The peak is, therefore, no longer a singlet and the splitting pattern and their associated coupling constants depend...
01:18Structure of Benzene: Molecular Orbital Model
According to the molecular orbital (MO) model, benzene has a planar structure with a regular hexagon of six sp2 hybridized carbons. As shown in Figure 1, each carbon is bonded to three other atoms with C–C–C and H–C–C bond angles of 120°. The C–H bond length is 109 pm, and the C–C bond length is 139 pm which is midway between the single bond length of sp3 hybridized carbons (154 pm) and sp2 hybridized carbons (133 pm).
01:23Nomenclature of Aromatic Compounds with a Single Substituent
Benzene is the simplest aromatic hydrocarbon or arene. The IUPAC names for simple monosubstituted benzene derivatives are derived by adding the substituent's name as a prefix to the parent benzene. For example, halobenzene, where the halogen could be fluoro (F), chloro (Cl), bromo (Br), and iodo (I).
01:11Nomenclature of Aromatic Compounds with Multiple Substituents
When more than one substituent is present on the benzene ring, the IUPAC nomenclature depends on the number of substituents present.
For disubstituted benzene derivatives, with two groups attached to the benzene ring, three constitutional isomers are possible. For example, consider dimethyl benzene, often called xylene, where the second methyl group can be substituted at the second, third, or fourth carbon. The relative position of the substituents is represented by prefixes ortho, meta, or...
For disubstituted benzene derivatives, with two groups attached to the benzene ring, three constitutional isomers are possible. For example, consider dimethyl benzene, often called xylene, where the second methyl group can be substituted at the second, third, or fourth carbon. The relative position of the substituents is represented by prefixes ortho, meta, or...
01:18Frost Circles for Different Conjugated Systems
The inscribed polygon method is consistent with Hückel’s 4n + 2 rule and helps to learn whether the given cyclic compound is aromatic or not. The compound is stable and aromatic if every bonding molecular orbital (MO) is completely filled with a pair of electrons. However, if the non-bonding or antibonding orbitals are filled with electrons, the compound is unstable and not aromatic. Consider the Frost circle diagrams for cycloalkenes containing 4 to 8 carbons.
01:07Structure of Benzene: Kekulé Model
In 1865, August Kekule suggested the structure of benzene according to the structural theory of organic chemistry based on the three assertions—formula of benzene is C6H6, all the hydrogens of benzene are equivalent, and each carbon must have four bonds due to its tetravalency.
He proposed that benzene has a cyclic structure of six carbon atoms attached to one hydrogen atom each, with three alternating pi bonds.
He proposed that benzene has a cyclic structure of six carbon atoms attached to one hydrogen atom each, with three alternating pi bonds.