Crystal structure and spectroscopic properties of trans-diisothiocyanatobis(2,2-dimethyl-1,3-diaminopropane)chromium(III) thiocyanate

The novel complex trans-[Cr(Me2tn)2(NCS)2]NCS·1/2H2O, where Me2tn represents 2,2-dimethylpropane-1,3-diamine, was prepared and its structure was determined by single-crystal X-ray diffraction at 150 K. The complex crystallizes in the space group P 1 ¯ of the triclinic system with two mononuclear formula units in a cell of dimensions a = 8.8359(6), b = 10.4926(7), c = 12.5136(9) Å and α = 66.124(2)°, β = 88.795(2)° and γ = 89.530(2)°. The chromium atom is in a slightly distorted octahedral environment coordinated by four N atoms of two chelating Me2tn and two N-bonded thiocyanate ligands in trans axial positions. The two six-membered rings in the complex cation have only anti chair–chair conformations with respect to each other. The mean Cr–N(Me2tn) and Cr–N(CS) bonds are 2.0807(15) and 1.9826(15) Å, respectively. The crystal structure is stabilized by N–H…S and N–H…N hydrogen bonds. The ligand field analysis as well as the IR and electronic spectral properties are discussed.