Mechanochemical synthesis of hemin-imidazole complexes

Solid state reactions of hemin and imidazole were performed by milling the crystalline materials in an agate mortar. The process was monitored by i.r. , x.r.d. and Mossbauer spectroscopies. Samples with different hemin to imid azole molar ratios were studied. The interactions of imidazole with the cen tral Fe atom and with the propionic acid groups in the periphery of the hem in molecule were detected. The latter interactions are suppressed by washin g with MeOH. Complexes with 1:2 and 1:4 hemin-to-imidazole molar ratios wer e identified.