Tuning Molecular Electron Affinities against Atomic Electronegativities by Spatial Expansion of a π‐System. Issue 9 (20th February 2023)

• Record Type: Journal Article
• Authors: Chulanova, Elena A.; Radiush, Ekaterina A.; Semenov, Nikolay A.; Hupf, Emanuel; Irtegova, Irina G.; Kosenkova, Yulia S.; Bagryanskaya, Irina Yu.; Shundrin, Leonid A.; Beckmann, Jens; Zibarev, Andrey V.
• Is Part Of: Chemphyschem. Volume 24:Issue 9(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-02-20
• Subjects: chalcogen-nitrogen compounds -- halogen compounds -- heteroatom π-systems -- main group chemistry -- molecular electron affinity; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.202200876
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: 2, 1, 3‐Benzochalcogenadiazoles C6 R4 N2 E (E /R ; E=S, Se, Te; R=H, F, Cl, Br, I) and C6 H2 R2 N2 E (E /R' ; E=S, Se, Te; R=Br, I) are 10π‐electron hetarenes. By CV/EPR measurements, DFT calculations, and QTAIM and ELI‐D analyses, it is shown that their molecular electron affinities (EAs) increase with decreasing Allen electronegativities and electron affinities of the E and non‐hydrogen R (except Cl) atoms. DFT calculations for E /R +e⋅ − →[E/R]⋅ − electron capture reveal negative ΔG values numerically increasing with increasing atomic numbers of the E and R atoms; positive ΔS has a minor influence. It is suggested that the EA increase is caused by more effective charge/spin delocalization in the radical anions of heavier derivatives due to contributions from diffuse (a real‐space expanded) p‐AOs of the heavier E and R atoms; and that this counterintuitive effect might be of the general character. Abstract : Size does matter : Replacing in 2, 1, 3‐benzochalcogenadiazoles C6 R4 N2 E and C6 H2 R2 N2 E (E=S, Se, Te; R=H, F, Cl, Br, I) lighter/smaller E and non‐hydrogen R atoms with heavier/bigger, i. e ., decreasing atomic electronegativities, increases molecular electron affinities.