10.1021/om0302490.s002
Anand Sundararaman
Anand
Sundararaman
Roger A. Lalancette
Roger A.
Lalancette
Lev N. Zakharov
Lev N.
Zakharov
Arnold L. Rheingold
Arnold L.
Rheingold
Frieder Jäkle
Frieder
Jäkle
Structural Diversity of Pentafluorophenylcopper
Complexes. First Evidence of π-Coordination of
Unsupported Arenes to Organocopper Aggregates
American Chemical Society
2003
unsymmetrical η 2
NMR
toluene molecules
meta carbon atoms
tetrameric cluster species
Cu
DMSO
2003-08-18 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Structural_Diversity_of_Pentafluorophenylcopper_Complexes_First_Evidence_of_Coordination_of_Unsupported_Arenes_to_Organocopper_Aggregates/3362062
The binding behavior of arenes toward pentafluorophenylcopper was investigated.
Crystallization of pentafluorophenylcopper from a mixture of 1,2-dichloroethane and
cyclohexane affords the homoleptic tetrameric complex [Cu(C<sub>6</sub>F<sub>5</sub>)]<sub>4</sub>, whereas a π-complex,
[Cu(C<sub>6</sub>F<sub>5</sub>)]<sub>4</sub>(η<sup>2</sup>-toluene)<sub>2</sub>, is obtained from toluene solution. The unique coordination of two
toluene molecules in [Cu(C<sub>6</sub>F<sub>5</sub>)]<sub>4</sub>(η<sup>2</sup>-toluene)<sub>2</sub> leads to major structural changes as the regular
square planar tetramer is distorted toward a butterfly structure with one short and one
long diagonal Cu···Cu distance of 2.5935(3) and 3.955(1) Å, respectively. The toluene
molecules are bound in an unsymmetrical η<sup>2</sup>-coordination mode with the shortest contacts
observed between copper and the <i>meta</i> carbon atoms (<i>d</i>(Cu−C) = 2.271(2), 2.298(2) Å) and
slightly longer distances to the <i>para</i> positions (<i>d</i>(Cu−C) = 2.339(2), 2.455(4) Å). Multinuclear
NMR studies show that complexation to the intact tetrameric cluster species also occurs in
neat solution of the aromatic species. Strongly coordinating solvents such as acetonitrile or
DMSO, however, lead to aggregate breakdown.