Crystal structure and spectroscopic properties of isothiocyanato[(3,14-dimethyl-2,6,13,17-tetraazatricyclo(16.4.0.07,12)docosane)]copper(II) thiocyanate

Abstract

A new complex [Cu(L¹)(NCS)]SCN, where L¹ = 3,14-dimethyl-2,6,13,17-tetraazatricyclo( 16.4.0.0^7,12)docosane is prepared and characterized by single crystal X-ray crystallographic analysis. The complex crystallizes in the triclinic space group P1̅ with two mononuclear formula units in a cell of dimensions a = 7.9681(2) Å, b = 8.8644(2) Å, c = 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 trans-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.