Unveiling the Electronic Structure of the Bi(+1)/Bi(+3) Redox Couple on NCN and NNN Pincer Complexes
| Autor: | Sergi Danés, Pedro Salvador, Diego M. Andrada, Martí Gimferrer |
|---|---|
| Přispěvatelé: | Agencia Estatal de Investigación |
| Rok vydání: | 2021 |
| Předmět: |
Química inorgànica
010405 organic chemistry Ligand chemistry.chemical_element Chemistry Inorganic 010402 general chemistry 01 natural sciences Article 0104 chemical sciences 3. Good health Bismuth Pincer movement Inorganic Chemistry Crystallography chemistry Oxidation state Proton affinity Reactivity (chemistry) Química quàntica Lewis acids and bases Physical and Theoretical Chemistry Quantum chemistry Lone pair |
| Zdroj: | Inorganic Chemistry, 2021, vol. 60, núm. 23, p. 17657-17668 Articles publicats (D-Q) DUGiDocs – Universitat de Girona instname Inorganic Chemistry |
| ISSN: | 1520-510X 0020-1669 |
| Popis: | Low-valent group 15 compounds stabilized by pincer ligands have gained particular interest, given their direct access to fine-tune their reactivity by the coordination pattern. Recently, bismuth has been employed in a variety of catalytic transformations by taking advantage of the (+1/+3) redox couple. In this work, we present a detailed quantum–chemical study on the electronic structure of bismuth pincer complexes from two different families, namely, bis(ketimine)phenyl (NCN) and triamide bismuthinidene (NNN). The use of the so-called effective oxidation state analysis allows the unambiguous assignation of the bismuth oxidation state. In contrast to previous studies, our calculations suggest a Bi(+1) assignation for NCN pincer ligands, while Bi(+3) character is found for NNN pincer complexes. Notably, regardless of its oxidation state, the central bismuth atom disposes of up to two lone pairs for coordinating Lewis acids, as indicated by very high first and second proton affinity values. Besides, the Bi–NNN systems can also accommodate two Lewis base ligands, indicating also ambiphilic behavior. The effective fragment orbital analysis of Bi and the ligand allows monitoring of the intricate electron flow of these processes, revealing the noninnocent nature of the NNN ligand, in contrast with the NCN one. By the dissection of the electron density into effective fragment orbitals, we are able to quantify and rationalize the Lewis base/acid character. Effective oxidation state analysis sheds light on the electronic structure of chemical systems. The oxidation state of bismuthinidene pincer complexes can be assigned as Bi(+1) or Bi(+3) depending on the nature of the ligands. Despite this assignation, the reactivity pattern as Lewis base or acid is similar. The occupation of the effective fragment orbitals gives a straightforward method to quantify the reactivity. |
| Databáze: | OpenAIRE |
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