In situ synthesis of mononuclear copper(II) complexes of the new tridentate ligand bis[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]amine.

Two mononuclear copper complexes, {bis[(3,5-dimethyl-1H-pyrazol-1-yl-κN(2))methyl]amine-κN}(3,5-dimethyl-1H-pyrazole-κN(2))(perchlorato-κO)copper(II) perchlorate, [Cu(ClO(4))(C(5)H(8)N(2))(C(12)H(19)N(5))]ClO(4), (I), and {bis[(3,5-dimethyl-1H-pyrazol-1-yl-κN(2))methyl]amine-κN}bis(3,5-dimethyl-1H-pyrazole-κN(2))copper(II) bis(hexafluoridophosphate), Cu(C(5)H(8)N(2))(2)(C(12)H(19)N(5))(2), (II), have been synthesized by the reactions of different copper salts with the tripodal ligand tris[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]amine (TDPA) in acetone-water solutions at room temperature. Single-crystal X-ray diffraction analysis revealed that they contain the new tridentate ligand bis[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]amine (BDPA), which cannot be obtained by normal organic reactions and has thus been captured in the solid state by in situ synthesis. The coordination of the Cu(II) ion is distorted square pyramidal in (I) and distorted trigonal bipyramidal in (II). The new in situ generated tridentate BDPA ligand can act as a meridional or facial ligand during the process of coordination. The crystal structures of these two compounds are stabilized by classical hydrogen bonding as well as intricate nonclassical hydrogen-bond interactions.