Synthesis, X-ray and Mossbauer study of iron(II) complexes with trithiocyanuric acid (ttcH3).: The X-ray structures of [Fe(bpy)3](ttcH) • 2bpy • 7H2O and [Fe(phen)3](ttcH2)(ClO4) • 2CH3OH • 2H2O

Iron(II) complexes with a combination of nitrogen-donor ligands and trithiocyanuric acid (ttcH(3)) of the composition [Fe(bpy)(2)(ttcH)] (.) 2H(2)O (1), [Fe(bpY)(3)](ttcH) (.) 2bpy (.) 7H(2)O (2), [Fe(terpyCl)(2)](ttcH(2))(2) (.) H2O (3), [Fe(phen)(2)(ttcH)] (.) 2H(2)O (4), [Fe-(nphen)(2)(ttcH)] (.) 4H(2)O (5) and [Fc(phen)(3)](ttcH(2))(ClO4) (.) 2CH(3)OH (.) 2H(2)O (6), where bpy = 2,2'-bipyridine, terpyCl = 4'-chloro-2,2':6',2'-terpyridine, phen = 1,10-phenanthroline, nphen = 5-nitro-1,10-phenanthroline, have been prepared. The compounds, except for 6, have been characterized by elemental analysis, Fe-57 Mossbauer, IR and UV-Vis spectroscopies. It has been found that the trithiocyanurate ion is either coordinated to the metal centre (1, 4 and 5) or situated outside the inner coordination sphere of the iron(II) ion (2, 3 and 6). The X-ray crystal structures of complexes 2 and 6 demonstrate that the ligands enforce a distorted octahedral geometry on the Fell ions with monoanionic 2 and dianionic 6 forms of uncoordinated trithiocyanuric acid. Density-functional theory (DFT) calculations (B3LYP/6-31 + G*) were used for the geometry optimisation and infrared frequencies calculations of differently protonated forms of the acid (ttcH(3), ttcH(2)(-) and ttcH(2)(-)). (C) 2004 Elsevier Ltd. All rights reserved.