Dynamic Covalent Properties of a Novel Indolo[3,2-b]carbazole Diradical.

Autor: Badía-Domínguez I; Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n, 229071, Málaga, Spain., Peña-Álvarez M; Present address: Centre for Science at Extreme Conditions & School of, Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD, UK.; MALTA-Consolider Team, Department of Physical Chemistry I, Chemistry Faculty, University Complutense of Madrid, 28040, Madrid, Spain., Wang D; Key Laboratory of Synthetic and Self-assembly Chemistry for, Organic Functional Materials, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China., Pérez Guardiola A; Department of Physical Chemistry, University of Alicante, 03080, Alicante, Spain., Vida Y; Departamento de Química Orgánica, Universidad de Málaga-IBIMA, Campus de Teatinos s/n, 29071, Málaga, Spain.; Centro Andaluz de Nanomedicina y Biotecnología-BIONAND, Parque Tecnológico de Andalucía, C/ Severo Ochoa 35, 29590 Campanillas, Málaga, Spain., Rodríguez González S; Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n, 229071, Málaga, Spain., López Navarrete JT; Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n, 229071, Málaga, Spain., Hernández Jolín V; Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n, 229071, Málaga, Spain., Sancho García JC; Department of Physical Chemistry, University of Alicante, 03080, Alicante, Spain., García Baonza V; MALTA-Consolider Team and Instituto de Geociencias IGEO (CSIC-UCM), University Complutense of Madrid, 28040, Madrid, Spain., Nash R; Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6DX, UK., Hartl F; Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6DX, UK., Li H; Key Laboratory of Synthetic and Self-assembly Chemistry for, Organic Functional Materials, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China., Ruiz Delgado MC; Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n, 229071, Málaga, Spain.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2021 Mar 22; Vol. 27 (17), pp. 5509-5520. Date of Electronic Publication: 2021 Feb 25.
DOI: 10.1002/chem.202005211
Abstrakt: This work describes the synthesis and properties of a dicyanomethylene-substituted indolo[3,2-b]carbazole diradical ICz-CN. This quinoidal system dimerises almost completely to (ICz-CN) 2 , which contains two long C(sp 3 )-C(sp 3 ) σ-bonds between the dicyanomethylene units. The minor open-shell ICz-CN component in the solid-state mixture was identified by EPR spectroscopy. Cyclic voltammetry and UV-visible spectroelectrochemical data, as well as comparison with reference monomer ICz-Br reveal that the nature of the one-electron oxidation of (ICz-CN) 2 at ambient temperature and ICz-CN at elevated temperature is very similar in all these compounds due to the prevailing localization of their HOMO on the ICz backbone. The peculiar cathodic behaviour reflects the co-existence of (ICz-CN) 2 and ICz-CN. The involvement of the dicyanomethylene groups stabilizes the close-lying LUMO and LUMO+1 of (ICz-CN) 2 and especially ICz-CN compared to ICz-Br, resulting in a distinctive cathodic response at low overpotentials. Differently from neutral ICz-CN, its radical anion and dianion are remarkably stable under ambient conditions. The UV/Vis(-NIR) electronic transitions in parent (ICz-CN) 2 and ICz-CN and their different redox forms have been assigned convincingly with the aid of TD-DFT calculations. The σ-bond in neutral (ICz-CN) 2 is cleaved in solution and in the solid-state upon soft external stimuli (temperature, pressure), showing a strong chromism from light yellow to blue-green. Notably, in the solid state, the monomeric diradical species is predominantly formed under high hydrostatic pressure (>1 GPa).
(© 2021 Wiley-VCH GmbH.)
Databáze: MEDLINE
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