Bi-nuclear nitrosyl iron complex with 2-mercapto-imidazolyl: Synthesis, structure and magnetic properties

Bi-nuclear neutral paramagnetic nitrosyl iron complex [Fe2(C3H3N2S)2(NO)4] (I) has been synthesized by the exchange reaction of Na2Fe2(S2O3)2(NO)4·4H2O with imidazole-2-thiol. As it follows from X-ray analysis, complex I (space group P2(1)/n, Z=2) has centrosymmetric dimeric structure, with the iron atoms linked via structural fragment -μ-N-C-S. Isomeric shift of IδFe is 0.196(1) mm/s and quadrupole resolution ΔEQ is 1.109(2) mm/s at T=293 K. As follows from magnetic measurements, there are two paramagnetic centers with spin 1/2 in molecules [Fe2(C3H3N2S)2(NO)4], which are connected by anti-ferromagnetic exchange (−34.6 cm−1).