Structural and Magnetic Properties of Copper(II) Coordination Polymers Containing Fluoride-Based Anions and Ancillary Organic Ligands

The fluoride (F−) and bifluoride (HF2−) anions have been little used in the self-assembly of molecular and polymeric magnets. We have recently synthesized several new compounds, namely CuF2(3-OHpy)4 (OHpy = hydroxypyridine) (1), Cu(SiF6)(2,6-me2pyz)4 (me2pyz = dimethylpyrazine) (2), CuF2(H2O)2(pyz) (pyz = pyrazine) (3) and [Cu(HF2)(pyz)2]BF4 (4). Compound 1 contains coordinate covalent and hydrogen bonding interactions that link the Cu(II) ions into 3D networks while 2 features square-pyramidal Cu(II) ions that are weakly bridged by SiF62− anions into 1D chains. Preliminary structural data indicate that compound 3 contains 1D Cu-pyz-Cu chains while 4 contains two dimensional [Cu(pyz)2]2+ layers, which held together via HF2− anions so as to form an unprecedented 3D network. The magnetic properties of each are briefly described herein.