Synthesis of a stable pentathiepin fused to a single cyclopentadienyl ring of ferrocene was performed by treatment of the corresponding dithiastannole as a synthetic equivalent of unstable ferrocene 1,2-dithiol with a sulfur source. On the other hand, deprotection of the dithinstannole gave a novel tetrathiocin comprised of two ferrocene units. The single-crystal X-ray diffraction Studies revealed the unprecedented sulfur-containing heterocycles bound to ferrocene units. (C) 2002 Elsevier Science Ltd. All rights reserved.