TY - JOUR
T1 - Structural diversity of pentafluorophenylcopper complexes. First evidence of π-coordination of unsupported arenes to organocopper aggregates
AU - Sundararaman, Anand
AU - Lalancette, Roger A.
AU - Zakharov, Lev N.
AU - Rheingold, Arnold L.
AU - Jäkle, Frieder
PY - 2003/8/18
Y1 - 2003/8/18
N2 - 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(C6F5)]4, whereas a π-complex, [Cu(C 6F5)]4(η2-toluene)2, is obtained from toluene solution. The unique coordination of two toluene molecules in [Cu(C6F5)]4(η 2-toluene)2 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 η2-coordination mode with the shortest contacts observed between copper and the meta carbon atoms (d(Cu-C) = 2.271(2), 2.298(2) Å) and slightly longer distances to the para positions (d(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.
AB - 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(C6F5)]4, whereas a π-complex, [Cu(C 6F5)]4(η2-toluene)2, is obtained from toluene solution. The unique coordination of two toluene molecules in [Cu(C6F5)]4(η 2-toluene)2 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 η2-coordination mode with the shortest contacts observed between copper and the meta carbon atoms (d(Cu-C) = 2.271(2), 2.298(2) Å) and slightly longer distances to the para positions (d(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.
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U2 - 10.1021/om0302490
DO - 10.1021/om0302490
M3 - Article
AN - SCOPUS:0041877138
SN - 0276-7333
VL - 22
SP - 3526
EP - 3532
JO - Organometallics
JF - Organometallics
IS - 17
ER -