| Popis: |
Copper(II) and iron(II, III) complexes of the tripodal ligand, tris(1-methyl-1 H -imidazol-2-yl)methanol (Htmim), have been synthesized and characterized by elemental analysis, 1 H NMR and IR spectroscopies, magnetic moment measurement and X-ray crystallography. The structure of the copper complex, [Cu 4 (tmim) 4 (CF 3 SO 3 ) 2 ](CF 3 SO 3 ) 2 ·2MeOH ( 1 ), can be regarded as a polyimidazole-linked tetranuclear cluster where each copper atom adopts a five-coordinate square-pyramidal geometry ligated by the tmim anion. The two iron complexes, [Fe II (Htmim) 2 ][Fe II Cl 4 ]·4MeOH ( 2 ) and [Fe III (Htmim) 2 ][Fe III Cl 4 ] 2 Cl ( 3 ), contain the isostructural [Fe(Htmim) 2 ] cation and tetrahedral [FeCl 4 ] − anion. While Htmim shows a normal tripodal tridentate mode in the iron complexes capping one face of an essentially octahedral coordination sphere, its deprotonated species exhibit an unusual non-tripodal tetradentate coordination with copper(II) ions. The observed magnetic moment at room temperature for 1 is 1.13 BM per Cu atom, consistent with antiferromagnetic coupling between the copper(II) atoms of the tetramer. Both 2 and 3 show magnetic properties consistent with low-spin electronic configurations of the cation and high-spin nature of the metal ion in the anion. |
Full Text from ScienceDirect