The synthesis and structure of terpyridine-N-oxide complexes of copper(II) perchlorate

The co-ordination of a series of terpyridine-N-oxide ligands to the Cu(ii) ion is reported. Addition of two equivalents of ligand results in the formation of the expected 2 : 1 six co-ordinate product, while the addition of one equivalent of ligand allows the isolation of 1 : 1 species if the ligand has a meridonal binding mode. The five complexes isolated were characterised in the solid state by X-ray crystallography while they are studied in solution using EPR, UV-vis spectroscopy and IR spectroscopy.

Synthesis and crystal structure of 2,3-bis[3-(2-pyridyl)pyrazol-1-yl]hydroquinone dihydrate at 158 K

2,3-Bis[3-(2-pyridyl)pyrazol-1-yl]hydroquinone dihydrate crystallises in the space group C2/c with half a molecule of the title compound and a water molecule in the asymmetric unit. A two-fold rotation axis relates the two 3-(2-pyridyl)pyrazol-1-yl substituents. The pyridine and pyrazole rings are approximately coplanar while the pyrazole ring is orthogonal to the benzene ring. Each water molecule is hydrogen bonded to the hydroxyl group and also to nitrogen atoms of two adjacent molecules; these hydrogen bonding interactions give rise to a two-dimensional network architecture.