Stepwise reduction of an asymmetric π-expanded pyracylene towards the crystalline radical trianion

Year: 2025

Type: article

Abstract: H NMR spectroscopy, evidenced the stepwise reduction process. The use of different solvents and secondary ligands enabled isolation of single crystals of three different reduced states of TPP with 1, 2, and 3 electrons added to its π-system. This provided a unique set of carbanions with gradually increasing negative charge for in-depth structural analysis of the outcomes of controlled electron addition to a non-planar and asymmetric nanographene, using X-ray crystallographic, spectroscopic, and theoretical tools. EPR spectroscopy measurements of the mono- and triply-reduced TPP products revealed distinct EPR splitting patterns. DFT calculations demonstrated a notable difference in the spin density distribution of these two open-shell products and provided insights into experimental EPR data. Moreover, the influence of the counterions on the "naked" TPP anions was illustrated computationally.

Source: Chemical Science

DOI: 10.1039/d4sc08255a

Authors: Yikun Zhu, Jan Borstelmann, Christian Neiss, Zheng Wei, Andreas Görling, Milan Kivala, Marina A. Petrukhina

Institutions: State University of New York, University at Albany, State University of New York, Heidelberg University, Friedrich-Alexander-Universität Erlangen-Nürnberg

Language: English

Topic: Synthesis and Properties of Aromatic Compounds

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: diamond

Funders: National Science Foundation, U.S. Department of Energy, Deutsche Forschungsgemeinschaft, Office of Science, Division of Materials Research, Division of Chemistry, Argonne National Laboratory

OpenAlex ID: W4406301128