Thiocyanate is one of the prototypical pseudohalide anions and it can be found in every area of contemporary chemistry, most commonly as a ligand in molecular metallocomplexes * , but also as an organic functional group , in biological chemistry as a key metabolite with potential anticarcinogenic function , and even in space . The study of thiocyanate has a long history. NCS - was first prepared and isolated by Porrett in 1814, well before the isolation of elemental bromine, fluorine and iodine. In this pioneering work, Porrett used HNCS to prepare 'sulferetted chyazate' salts † of a number of elements, including K, Na, Ca, Al, Ba, Sr, Ag, Hg, Cu, Pb, Sn, Bi, Mn, Zn, Co, Ni, Pd, U, Mo and Cr. Porrett's work highlights not only the diversity of thiocyanate chemistry but also how much is yet to be determined about metal thiocyanate chemistry: although these compounds were reported more than two hundred years ago, the synthesis and structures of Pd, U, Mo, Al and Cr thiocyanate have not been confirmed. The presence of these open questions contrasts with the 'true' metal halides where nearly every feasible composition has been structurally characterized, from extreme oxidation states (e.g. VCl 5 ) to highly radioactive compounds (e.g. EsCl 3 ). Pseudohalides thus offer synthetic inorganic chemists the rare opportunity to create new (pseudo-)binary compounds (Fig. ).