CRYSTAL STRUCTURE AND SPECTROSCOPIC PROPERTIES OF ISOTHIOCYANATO[(3,14-DIMETHYL-2,6,13,17-TETRAAZATRICYCLO(16.4.0.0<sup>7,12</sup>)DOCOSANE)]COPPER(II) THIOCYANATE
A new complex [Cu(L<sup>1</sup>)(NCS)]SCN, where L<sup>1</sup> = 3,14-dimethyl-2,6,13,17-tetraazatricyclo(16.4.0.0<sup>7,12</sup>)docosane is prepared and characterized by single crystal X-ray crystallographic analysis. The complex crystallizes in the triclinic space group P with two mononuclear formula units in a cell of dimensions <i>a</i> = 7.9681(2), <i>b</i> = 8.8644(2), <i>c</i> = 18.8165(5) Å, α = 76.758(70), β = 78.490(2) and γ = 77.679(2)°. The Cu(II) ion is five-coordinate in an axially elongated square pyramidal environment, with the four amine N atoms at the equatorial positions and the N atom of one thiocyanate at an apical site. The macrocyclic cyclam moiety adopts a stable <i>trans</i>-III configuration. The Cu-N basal plane bond length has a mean value of 2.037(2) Å. The coordinated Cu-NCS bond length is 2.322(3) Å. The N atom of the thiocyanate anion is connected to the macrocyclic ligand of the cation via an NH…N(CS) hydrogen bond. The UV-visible absorption and IR spectral properties are also discussed.