Intramolecular hydrogen bonding studies in mono-, bis and poly-[N-formyl-N'-aryl(alkyl) substituted thiourea] ferrocene derivatives

For several years, we have been engaged in the synthesis and coordination chemistry of ferrocenyl-containing acyl thiourea derivatives[1-2].The existence of intramolecular hydrogen bond is another interesting problem to be investigated. A series of ferrocene derivatives containing N-formyl-N'-aryl (alkyl) thiourea side chains were synthesized by treating mono- or bis ferrocenoyl isothiocyanate with various amines. It was found that intramolecular hydrogen bond between the carbonyl oxygen and the hydrogen atom on N' is common in this kind of compound. The introduction of a ferrocene fragment into the molecule often leads to its better crystallizability.