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Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Carbodicarbenes and related divalent carbon(0) compounds
Susanne Klein1, Ralf Tonner, Gernot Frenking
1Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|July 21, 2010
Summary
This study computationally explores divalent carbon(0) compounds, termed carbones, revealing their unique L-->C<--L bonding. These carbones act as potent double Lewis bases, offering new avenues for low-coordinate carbon chemistry research.
Area of Science:
- Quantum chemistry
- Theoretical inorganic chemistry
- Computational organic chemistry
Background:
- Divalent carbon compounds exhibit unique bonding and reactivity.
- Understanding the electronic structure of low-coordinate carbon species is crucial for advancing chemical synthesis and catalysis.
Purpose of the Study:
- To investigate the electronic structure and bonding characteristics of fourteen divalent carbon(0) compounds (carbones).
- To analyze the donor-acceptor interactions (L-->C<--L) in these carbones.
- To assess their potential as Lewis bases and their interactions with BH(3) ligands.
Main Methods:
- Density Functional Theory (DFT) calculations.
- Ab initio quantum-chemical methods.
- Charge- and energy-decomposition analysis.
Main Results:
- Divalent carbon(0) character was confirmed in compounds 1-10 to varying degrees.
- Strong carbone-type bonding (L-->C<--L) was observed in carbodicarbenes, bent allenes, and carbocarbenephosphoranes.
- Carbocarbenephosphoranes exhibit high proton affinities and bind two BH(3) ligands strongly, suggesting isolability.
- Other compounds also form stable bis-BH(3) adducts, acting as twofold Lewis bases.
Conclusions:
- Compounds 1-10 are identified as carbones with a two-electron pair at the carbon atom.
- Carbone chemistry differs from carbenes; carbones are pi donors and double Lewis bases.
- Theoretical findings suggest new experimental research directions for low-coordinate carbon compounds.
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