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Bis(catecholato)silanes: assessing, rationalizing and increasing silicon's Lewis superacidity
Deborah Hartmann1, Marcel Schädler1, Lutz Greb1
1Anorganisch-Chemisches Institut , Ruprecht-Karls-Universität Heidelberg , Im Neuenheimer Feld 275 , 69120 Heidelberg , Germany .
Chemical Science
|September 7, 2019
Summary
This study reveals the significant Lewis acidity of bis(catecholato)silanes, establishing a consistent trend for the first time. Bis(perbromocatecholato)silane emerges as a new record holder for silicon Lewis superacids.
Area of Science:
- Organosilicon Chemistry
- Lewis Acid Characterization
- Superacid Development
Background:
- Bis(catecholato)silanes are known but their Lewis acidity is poorly documented.
- Understanding Lewis acidity is crucial for catalysis and materials science.
Purpose of the Study:
- To synthesize and characterize substituted bis(catecholato)silanes and their adducts.
- To comprehensively assess the Lewis acidity of these compounds using multiple methods.
- To establish a consistent Lewis acidity trend for bis(catecholato)silanes.
Main Methods:
- Synthesis and characterization of novel bis(catecholato)silane derivatives.
- Assessment of Lewis acidity via effective, global, and intrinsic scaling methods.
- High-level theoretical calculations (DLPNO-CCSD(T)) and chemical bonding analysis.
Main Results:
- Demonstrated general Lewis acidic nature of bis(catecholato)silanes.
- Established the first consistent Lewis acidity trend for this class of compounds.
- Identified bis(perbromocatecholato)silane as a new record holder silicon Lewis superacid.
Conclusions:
- Lewis acidity in bis(catecholato)silanes is significantly influenced by π-back bonding, not just inductive effects.
- This work provides a comprehensive understanding and a new benchmark for silicon Lewis superacids.
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