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 P1¯ 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.