Two Cu complexes of 3,4,5-tri-methyl-1-pyrazole.

The crystal structure of complexes of 3,4,5-tri-methyl-1-pyrazole with CuCl·2HO and Cu(NO)·2.5HO are presented, namely di-μ-chlorido-bis[chloridobis(3,4,5-trimethyl-1-pyrazole-κ)copper(II)], [CuCl(CHN)] () and aquatetrakis(3,4,5-trimethyl-1-pyrazole-κ)copper(II) dinitrate, [Cu(CHN)(HO)](NO) (), and compared to the previously determined structures for 3-methyl-1-pyrazole and 3,5-di-methyl-1-pyrazole. CuCl forms a 2:1 ligand-to-metal chloride-bridged complex with 3,4,5-tri-methyl-1-pyrazole, with a square-pyramidal coordination geometry about each copper(II) center.