# Chemical Oxidation of Chrysene: A Structural and Theoretical Description of a Mixed-Valent Trimeric Radical Cation

## TL;DR

This paper describes the chemical oxidation of chrysene into a unique trimeric radical cation structure, analyzed through crystallography and computational methods.

## Contribution

The study provides a structural and theoretical characterization of a mixed-valent trimeric radical cation formed from chrysene oxidation.

## Key findings

- The trimeric chrysene radical dication forms with two Ga2Cl7– anions, as shown by X-ray diffraction.
- Computational analysis reveals uneven charge distribution, with terminal chrysenes having higher positive charges.
- The charged trimer exhibits weaker interactions compared to the neutral form, indicating electrostatic repulsion.

## Abstract

Chemical oxidation
of chrysene with GaCl3 affords
a
trimeric chrysene radical dication, [(C18H12)3]2+, crystallized with two Ga2Cl7
– anions, as revealed by single crystal
X-ray diffraction analysis. In the crystal structure, 1D π-stacked
columns of chrysene with interplanar contacts averaged at 3.303(3)
Å are separated by Ga2Cl7
– anions. Computational studies reveal that the positive charge is
concentrated largely on the terminal chrysene units with charges of
+0.84 and +0.80, while the center chrysene has a comparatively lower
charge of +0.36. This charge distribution is corroborated with structural
features of the trimer, as the terminal chrysene molecules exhibit
a more pronounced core deformation. Taking the neutral trimer as a
reference, much weaker interactions are observed in the title chrysene
trimer bearing a +2 charge, suggesting the presence of substantial
electrostatic repulsion.