Magnetic anisotropy and structure of hexa(urea)titanium salts

Abstract

The magnetic anisotropy of Ti(urea)₆(ClO₄)₃ and Ti(urea)₆I₃ has been measured between 80 and 300 K. The behaviour is interpreted in terms of the model of the ²D term of the d¹ configuration under the influence of a ligand field of cubic symmetry with a trigonal component superimposed, and of spin–orbit coupling. It is found that the orbital angular momentum reduction factor is quite low at ca. 0·45, and that the spin–orbit coupling constant is less than one half of the free-ion value. The ground ²T_2g term is split by ca. 500 cm^–1, and the origin of this splitting does not seem to be to any large extent due to the ‘twist’ of ca. 5° about the C₃ axis observed in the co-ordination octahedron from structural studies.