Revisited crystal symmetry of the high-spin form of the iron(II) spin-crossover complex dicyano[2,13-dimethyl-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene]iron(II) monohydrate.

The title iron(II) complex, [Fe(CN)(2)(C(15)H(23)N(3)O(2))].H(2)O, is of interest to the spin-crossover community because of its unusual temperature-dependent magnetic behaviour as well as its relatively high relaxation temperature for the light-induced spin-crossover phenomenon. Structural modifications are strongly suspected to cause the unusual thermal spin-crossover features. Recently, the high-spin crystal structure has been reported but with an inadequate space group. In the present paper, the crystal structure is corrected by a new investigation, and some consequences for the structure-property relationships of this complex are discussed. The Fe(II) ion is seven-coordinate and lies on a twofold axis.