6533b838fe1ef96bd12a524d

RESEARCH PRODUCT

Versatility and dynamics of the copper(I) coordination sphere in sterically hindering tris(pyrazolyl)methane-incorporating macrobicycles

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description

Two arene-capped macrobicycles (1 and 2) incorporating the tris(pyrazolyl)methane (Tpm) chelate have been prepared from a benzylthiol-functionalized Tpm precursor (3). Reaction of either macrobicycle with Cu(CH3CN)4+ leads to tetrahedral or trigonal-planar, fluxional complexes incorporating the Cu(CH3CN)+ subunit ([Cu(1)(CH3CN)]+ and [Cu(2)(CH3CN)]+). The acetonitrile ancillary ligand does not fit inside the macrobicycle cavity and can be removed by heating under vacuum, which produces the [Cu(1)]+ and [Cu(2)]+ species probably involving intramolecular thioether coordination. The [Cu(1)(CH3CN)]+ complex was shown to convert slowly in wet acetone into a helical coordination polymer, which is formulated as [Cu(1)(H2O)]nn+. In the crystal, the metal cation in tetrahedral geometry is bound to two pyrazole nitrogens and bridges two macrobicyclic subunits by intermolecular thioether sulfur coordination. Its coordination sphere is remarkably completed by a water molecule that is located inside the macrobicycle and is bound to the uncoordinated pyrazole fragment and to the mesitylene cap by OH⋯N and OH⋯π hydrogen bonding interactions.