Characterization of copper(II) coordination compounds of 5,7-dimethyl[1,2,4]triazolo[1,5- a]pyrimidine: the crystal structure of diaquatetrakis(5,7-dimethyl[1,2,4]triazolo[1,5- a]pyrimidine- N3)-copper(II) hexafluorophosphate

Abstract

Copper(II) coordination compounds of several CuA 2 salts (A = PF 6, BF 4, ClO 4, CF 3SO 3 or NO 3) with 5,7-dimethyl[1,2,4]triazolo[1,5- a]pyrimidine (dmtp) as a ligand have been studied. The crystal structure of [Cu(dmtp) 4(H 2O) 2](PF 6) 2 is described. This compound is monoclinic, space group P2 1/ c, a = 11.826(2) Å, b = 9.463(2) Å, c = 17.673(3) Å, β = 97.50(1)°, Z = 2, d calc. = 1.66 Mg m −3, and has been refined to a final discrepancy factor ( R) of 0.0382 based on 2316 reflections. The structure consists of PF − 6 anions and centrosymmetric mononuclear [Cu(dmtp) 4(H 2O) 2] 2+ cations, Cu 2+ being coordinated by four equatorial N(3)-bonded dmtp molecules with CuN = 2.019 and 2.050 Å, and by two axial water molecules with CuO = 2.650 Å. The water molecules form intramolecular hydrogen bonds with the dmtp N(4) atoms.