Iron(II) complexes of 1-benzyl-2-phenylbenzimidazole and 2-coumarinylbenzimidazole

Summary Iron(II) complexes of 1-benzyl-2-phenylbenzimidazole (BPBI) and 2-coumarinylbenzimidazole (CBI) have been prepared and characterised. The chloride, bromide, iodide and thiocyanate complexes have the general formula FeL₂X₂ (where L = BPBI or CBI) while the perchlorate complex of CBI has the composition Fe(CBI)₃](CIO₄)₂. The perchlorate complex behaves as a 1 : 2 electrolyte in nitrobenzene and methanol; Fe(BPBI)₂I₂ shows considerable dissociation in nitrobenzene while the other complexes behave as nonelectrolytes. The i.r. spectra of the complexes suggest that N(3) of BPBI and N(3) together with the CO group of CBI are the coordination sites. The magnetic and spectral evidence suggests a regular octahedral geometry for the perchlorate complex and pseudotetrahedral configuration for the iodide and thiocyanate complexes. The other complexes appear to be distorted octahedral with halide bridging.Author to whom all correspondence should be addressed.