The Fe(III) complex of N,N',N''-tris(3-hydroxy-6 methyl-2-pyridyl-methyl)-1,4,7-triazacyclononane Fe(C27H33N6O3.C6H6.2H(2)O)

The crystal structure of FeC27H33N6O3 . C6H6 . 2H(2)O has been determined. This complex is orthorhombic and crystallizes in space group P2(1)2(1)2(1) with cell parameters a = 13.226(4) Angstrom, b = 19.410(6) Angstrom, c = 12.779(4) Angstrom, V = 3281(2) Angstrom(3), Z = 4 and Mr = 659.61. R(F) = 0.056 for 1626 observed reflections with iota > 3 sigma(iota) and 199 variables, The structure consists of a neutral complex of FeC27H33N6O3 with Fe(III) in a slightly distorted octahedral environment coordinated to three tertiary amino nitrogen atoms and three phenolate-like oxygen atoms (FeN3O3). The average Fe-N distance = 2.22 Angstrom, Fe-O = 1.91 Angstrom. The twist angle of 54.0 degrees is nearly the value expected for a purely octahedral complex (60 degrees) and a correlation between the twist angle and the stability of the complex in solution is suggested.