REACTIONS OF RING-SUBSTITUTED TITANOCENE DICHLORIDES WITH THIOCYANATE IONS - SYNTHESIS OF NEW S-BONDED THIOCYANATO TITANOCENE COMPLEXES, AND CRYSTAL-STRUCTURE OF ((T)BU-C5H4)2TI(NCS)2

The asymmetrical titanocene dichloride (1,3-(t)Bu2-C5H3)((t)Bu2-C5H4)TiCl2 (1) has been prepared from (1,3-(t)Bu2-C5H3)TiCl3 and ((t)Bu-C5H4)Li. The reactions of I and of (1,3-(t)Bu2-C5H3)2TiCl2 with an excess of ammonium thiocyanate afforded the S-bonded thiocyanato complexes (1,3-(t)Bu2-C5H3)((t)Bu-C5H4)Ti(SCN)2 (IV) and (1,3-(t)Bu2-C5H3)2Ti(SCN)2 (V) respectively. A similar reaction of ((t)Bu-C5H4)2TiCl2 with excess ammonium thiocyanate produced the S-bonded thiocyanato complex ((t)Bu-C5H4)2Ti(SCN)2 (II) as a minor product and the N-bonded thiocyanato complex ((t)Bu-C5H4)2Ti(NCS)2 (III) as the major product. Similar reaction of ((t)Bu-C5H4)2TiCl2 With ammonium thiocyanate in 1:1 molar ratios gave ((t)Bu-C5H4)2Ti(Cl)(NCS) (VI). Crystal structure of III was determined.