New Cu(II) compounds with ligands synthesized through nucleophilic addition of pyrazoles to dicyanamide. Synthesis, crystal structures and spectroscopy

Three newly synthesized ligands, i.e. (pyrazolecarbimido)-cyanoamine (abbreviated as Hdcapz), (3-methylpyrazolecarbimido)cyanoamine (abbreviated as Hdcampz) and (3,5-dimethylpyrazolecarbimido)cyanoamine (abbreviated as Hdcadmpz) are presented in this study, including the X-ray crystal structures for two of them, as well as their coordination behaviour with respect to Cu(II).The structures of 4 Cu(II) compounds with dmpzdca, i.e. the mononuclear compounds [Cu(dcadmpz)2(H2O)] (3), [Cu(dcadmpz)2] (4), the polynuclear compound [Cu3(dcadmpz)4(CH3OH)0.6(H2O)0.4](ClO4)2(CH3OH)1.25(H2O)0.2 (5) and the triangular-based bis-trinuclear compound [Cu3(Hdcadmpz)3(NO3)3(CH3OH)2]2·[Cu3(Hdcadmpz)3(NO3)3(CH3CN)] (6) are also presented, together with their spectroscopic properties (ligand field, EPR and IR). The geometry around the Cu(II) ion for 3 and 4 is square pyramidal. The three crystallographic independent Cu(II) ions in compound 5 have a distorted square pyramidal geometry. The trinuclear compound 6 consists of three different crystallographically independent trinuclear units with a total of 9 different independent Cu(II) ions. The geometry for the Cu(II) ions vary from distorted square pyramidal to distorted octahedral.

Graphical abstractFour new Cu(II) compounds with the new ligand Hdmpzdca are presented. Apart from the mononuclear compounds [Cu(dcadmpz)2(H2O)] and [Cu(dcadmpz)2] also trinuclear based polynuclear compounds are presented with their 3D structures and spectral properties.Figure optionsDownload full-size imageDownload as PowerPoint slide