High-Valent Copper(III) Cyanide Tetramer Stabilized by Trifluoromethyl Ligands and its Multifaceted Reactivity
Abstract
High-valent neutral copper(III) complexes are highly elusive species with strong Lewis acidic properties and high effective nuclear charge. Herein, an unprecedented copper(III) cyanide [Cu(CF3)2(CN)]4 stabilized in a tetrameric square-like scaffold with bridging cyanide ligands was isolated and fully characterized in the form of tetrahydrate [Cu(CF3)2(CN)(H2O)]4, including X-ray crystallography. This tetrameric scaffold is stable to Lewis bases, while the apical ligands easily undergo substitution to acetonitrile and cis-trans isomerization in the presence of acetone. Lewis acidity of copper(III) cyanides – hypothetical Cu(CF3)2(CN) and a tetrameric scaffold [Cu(CF3)2(CN)]4 – was evaluated by experimental and computational methods. Relevance of the [Cu(CF3)2(CN)(solv)]4 scaffold for carbon-carbon bond formation was demonstrated by spontaneous reductive elimination of CF3CN at room temperature in high yield, and trifluoromethylation of a boronic acid.
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BibTeX
@misc{motornov2026highvalent,
title = {{High-Valent Copper(III) Cyanide Tetramer Stabilized by Trifluoromethyl Ligands and its Multifaceted Reactivity}},
author = {Vladimir Motornov and Niklas Limberg and Ahmet N. Toraman},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010871/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010871/v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - High-Valent Copper(III) Cyanide Tetramer Stabilized by Trifluoromethyl Ligands and its Multifaceted Reactivity
AU - Vladimir Motornov
AU - Niklas Limberg
AU - Ahmet N. Toraman
PY - 2026
DA - 2026/10/22
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010871/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010871/v1
AB - High-valent neutral copper(III) complexes are highly elusive species with strong Lewis acidic properties and high effective nuclear charge. Herein, an unprecedented copper(III) cyanide [Cu(CF3)2(CN)]4 stabilized in a tetrameric square-like scaffold with bridging cyanide ligands was isolated and fully characterized in the form of tetrahydrate [Cu(CF3)2(CN)(H2O)]4, including X-ray crystallography. This tetrameric scaffold is stable to Lewis bases, while the apical ligands easily undergo substitution to acetonitrile and cis-trans isomerization in the presence of acetone. Lewis acidity of copper(III) cyanides – hypothetical Cu(CF3)2(CN) and a tetrameric scaffold [Cu(CF3)2(CN)]4 – was evaluated by experimental and computational methods. Relevance of the [Cu(CF3)2(CN)(solv)]4 scaffold for carbon-carbon bond formation was demonstrated by spontaneous reductive elimination of CF3CN at room temperature in high yield, and trifluoromethylation of a boronic acid.
ER -