p-Block Element Catecholates: Lewis Superacidic, Constitutionally Dynamic, and Redox Active

Abstract

Numerous strategies for enhancing the reactivity and properties of p-block elements have been devised in the past decades. This Account discusses our approaches by distinct ligand control on p-block elements in their normal (group) oxidation states. Catecholato ligands on silicon, germanium, or phosphorus produce a range of rewarding properties. Substantial electron withdrawal paired with structural constraint effects (influence of deformation energy) impart Lewis superacidity to these abundant elements. The ease of synthesis of such species facilitates screening in catalysis, promising a range of applications by powerful bond activation. Low-barrier Si–O/Si–O bond metathesis provides the most abundant bond in our Earth’s crust, with adaptive features under mild conditions, and establishes a new branch of constitutional dynamic chemistry. The redox-active character of catecholates grants access to novel compounds with tunable open-shell features. Overall, p-block catecholates offer unique opportunities due to their versatile features that will enrich the chemistry of the main-group elements.

1 Introduction

2 Halogenated Catecholates at Silicon Cause Substantial Lewis Acidity

3 Constitutional Dynamics Cause a Structural Mystery

4 Strong Silicon Lewis Acids Allow the Exploration of Uncharted Structures, Bond Activations, and Catalysis

5 The Catechol Approach on Other Elements: Germanium and Phosphorus

6 Catechols Are Redox Active: Also at Silicon

7 Conclusion

Key words

catechols - Lewis acids - bond activation - constitutional dynamics - diradicals - superacids

Publication History

Received: 20 June 2023

Accepted after revision: 04 July 2023

Accepted Manuscript online:
04 July 2023

Article published online:
29 August 2023

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