Self-assembly of copper(I) complexes into three-dimensional co-ordination polymers with channel networks by hydrogen bonding or by tridentate ligands

Abstract

Reaction of the appropriate copper(I) salt with 3-cyano-6-methylpyridin-2(1H)-one (Hcmp) gave three polymeric co-ordination compounds, [Cu(cmp)(Hcmp)₃]·C₅H₁₂1, [Cu₂(Hcmp)₄(Me₂CO)₂][BF₄]₂2 and [Cu₅(cmp)₄]ClO₄3, the structures of which have been determined by X-ray crystallography. Complex 1 contains a three-dimensional supramolecular framework of tetrahedral CuN₄ centres linked by intermolecular hydrogen bonds through the pyridone N and O atoms. The open square microchannels created enclathrate n-pentane as the guest molecule. Complex 2 contains a dimeric unit weakly bound by the bridging acetone oxygen atoms. Each Hcmp moiety in the dimer is hydrogen-bonded pairwise to one adjacent Hcmp molecule belonging to the other dimer giving a one-dimensional array of copper atoms. The unique structural feature of complex 3 is that it does not involve hydrogen bonding as in 1 or 2, instead each cmp monoanion employs all its three functional groups bridging three copper atoms forming a supramolecular channel architecture containing a Cu₄ cluster. The results are discussed in terms of designing new inorganic solids by the self-assembly of copper(I) complexes.