Magnetochemistry at low temperatures: Crystal structure and magnetic susceptibility of [CoCl2(3,5-lutidine)2]

Abstract

The crystal structure of [CoCl2(3,5-lutidine)2] along with magnetic susceptibility measurements over the temperature interval 50 mK-4.2 K are reported. The space group is P21/c, with a = 13.075(2), b = 15.903(4), and c = 8.035(1) Å; the angle β = 101.00(2)°. There are four molecules in the unit cell. The molecules are distorted tetrahedra (the Cl-Co-Cl angle is 120.29°) and well-isolated from each other. The magnetic anisotropy of single crystals is large and due to the zero-field splitting. The data may be fit by the spin-Hamiltonian parameters g{norm of matrix} = 2.1±0.1, g⊥ = 2.1±0.1 and 2D/kB = (10.5± 1) K. Measurements of the susceptibility of a polycrystalline powder sample show that magnetic ordering does not occur down to 50 mK. This is consistent with the crystal structure. © 1988.