The Redox Properties of Germylenes Stabilized by N‐Donor Ligands

The Redox Properties of Germylenes Stabilized by N‐Donor Ligands Full article

Journal

European Journal of Inorganic Chemistry
ISSN: 1434-1948 , E-ISSN: 1099-0682

Output data

Year: 2021, Volume: 2021, Number: 27, Pages: 2755-2763 Pages count : 9 DOI: 10.1002/ejic.202100369

Authors

Kozmenkova Anna Ya. ¹ , Timofeeva Vladislava A. ^1,2 , Mankaev Badma N. ³ , Lalov Andrey V. ¹ , Saverina Evgeniya A. ¹ , Egorov Mikhail P. ¹ , Karlov Sergey S. ³ , Syroeshkin Mikhail A. ¹

Affiliations

1	Laboratory for Carbene Analogs and Related Intermediates, N.D. Zelinsky Institute of Organic Chemistry, 119991 Moscow, Russia
2	Laboratoire Hétérochimie Fondamentale et Appliquée (UMR 5069) Université de Toulouse CNRS 31062 Toulouse France
3	Chemistry Department, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia

Germylenes, organic compounds of divalent germanium, are often considered as promising catalytic systems efficient in reactions of oxidative addition and reductive elimination, including SET reactions. However, the systematic studies of their redox properties, allowing for the quantitative evaluation of the levels of frontier molecular orbitals and the stability of single electron transfer products, are extremely limited in number. In this work, a series of germylenes with various types of stabilization: N−Ge−N, (N→)C−Ge−C(←N), N−Ge−N(←N), O−Ge−O(←N) и (N→)O−Ge−O(←N) (“−“ -a covalent bond, stabilization is achieved by p-donation of a lone pair of electrons of N or O, “→” -donor-acceptor bond) were characterized by cyclic voltammetry. The results were compared with UV/Vis spectroscopy data and DFT calculations. All germylenes studied in MeCN and THF with Bu4NPF6 as a supporting electrolyte are chemically irreversibly oxidized in the potential range of 0.5–1.4 V vs. Ag/AgCl. In all cases, as estimated by the quantum chemical calculations, the HOMO remains at the covalently unsaturated germanium center although being significantly redistributed over the molecular system. In turn, electroreduction of germylenes is possible only in the presence of a strong electron-withdrawing substituent or a pyridine ring depleted in electron density donated to germanium. In both cases, the LUMO is localized exactly on these moieties and is absent on the germanium. Thus, the use of stabilizing groups makes it possible both to improve germylene stability and to fine-tune their HOMO level that determines their ability to participate in oxidative addition reactions.

Kozmenkova A.Y. , Timofeeva V.A. , Mankaev B.N. , Lalov A.V. , Saverina E.A. , Egorov M.P. , Karlov S.S. , Syroeshkin M.A.
The Redox Properties of Germylenes Stabilized by N‐Donor Ligands
European Journal of Inorganic Chemistry. 2021. V.2021. N27. P.2755-2763. DOI: 10.1002/ejic.202100369 WOS Scopus OpenAlex

Web of science:	WOS:000661720000001
Scopus:	2-s2.0-85107903795
OpenAlex:	W3164294891

DB	Citing
OpenAlex	11
Scopus	12
Web of science	11