Anion influences on the solid state coordination chemistry of copper-bispyrazole materials

The reactions of the p-xylene-bridged and methylene-bridged bipyrazolyl ligands 1,4-bis[(3',5'-dimethyl-1H-pyrazole-4'-yl)methylene]benzene (xdpH₂) and bis[(3',5'-dimethyl-1H-pyrazole-4'-yl)]methane (mdpH₂) with the appropriate copper salt have provided eight unique members of the Cu/bipyrazole/X system with X = Cl^-, Br^-, I^- and SO₄^2-. The anionic component of [Cu(xdpH₂)(H₂O)]Cl·H₂O (1·H₂O) acts as a simple charge-compensating counterion. In contrast, the anionic units of [Cu(xdpH₂)Cl₂]·2DMF (2·2DMF), [Cu(xdpH₂)Cl₂(DMF)]·DMF (3·DMF), [Cu₂(xdpH₂)₂Br₂] (4), [Cu(mdpH₂)Br₂] (5), [Cu₄(xdpH₂)₄I₄] (6), [Cu₂(xdpH₂)₂(SO₄)]·H₂O (7·H₂O) and [Cu₂(xdpH₂)₂(SO₄)]·2H₂O (8·2H₂O) are involved in bonding to the copper sites. Compounds 1, 4, and 6-8 contain Cu(I) sites while compounds 2, 3, and 5 are polymers of Cu(II). Compounds 1-5 and 7 are one-dimensional, while 8 is two-dimensional and 6 is three-dimensional. Considering the {Cu₄I₄} clusters of 6 as nodes, the structure is a fivefold interpenetrated framework with individual networks adopting the common {3³.12³} topology in Schlafli notation.