Crystal structure, paramagnetic anisotropy, and zero-field splitting in intermediate-spin chlorobis(NN-di-isopropyldithiocarbamato)iron(III)-chloroform (1/1)

The crystal structure of the title complex has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least-squares procedures to R 0.072 for 4 066 observed reflections. Crystals are triclinic, with space group P1, unit-cell dimensions a = 1 350.5(5), b = 1 070.6(3), c = 986.2(3) pm, α = 96.12(2), β = 93.13(2), γ = 108.72(2)°, and Z = 2. The molecular structure is similar to those observed in other [FeX(S₂CNR₂)₂] derivatives, the iron atom lying in a pseudo-square-pyramidal environment with apical Cl [Fe-Cl 228.1(3), mean Fe-S 228_.7 pm]. The lattice contains a chloroform solvent molecule with occupancy 0.8₇. The magnetic anisotropy has been studied in the range 80-300 K. The rhombic molecular anisotropies have been deduced following the method of Ghose, and found to be similar to those of [FeCl(S₂CNEt₂)₂], their signs establishing a ⁴A₂ ground state. The zero-field splitting parameters have been deduced from the experimental data, and found to be consistent with previous e.s.r. studies.