 their proper formula is [Zn(S2CNR2)2]2.Each Zn center is in a distorted pentacoordinate site, with four Zn-S bonds of 2.3 Å length and one Zn---S interaction >2.8 Å in length.Mono-zinc derivatives are obtained by adding strong ligands (L) such as amines, which give adducts Zn(S2CNR2)2L.