Diaryl dithiocarbamates: synthesis, oxidation to thiuram disulfides, Co(III) complexes [Co(S 2 CNAr 2 ) 3 ] and their use as single source precursors to CoS 2 .

Air and moisture stable diaryl dithiocarbamate salts, Ar 2 NCS 2 Li, result from addition of CS 2 to Ar 2 NLi, the latter being formed upon deprotonation of diarylamines by n BuLi. Oxidation with K 3 [Fe(CN) 6 ] affords the analogous thiuram disulfides, (Ar 2 NCS 2 ) 2 , two examples of which (Ar = p -C 6 H 4 X; X = Me, OMe) have been crystallographically characterised. The interconversion of dithiocarbamate and thiuram disulfides has also been probed electrochemically and compared with that established for the widely-utilised diethyl system. While oxidation reactions are generally clean and high yielding, for Ph(2-naphthyl)NCS 2 Li an ortho -cyclisation product, 3-phenylnaphtho[2,1- d ]thiazole-2(3 H )-thione, is also formed, resulting from a competitive intramolecular free-radical cyclisation. To demonstrate the coordinating ability of diaryl dithiocarbamates, a small series of Co(III) complexes have been prepared, with two examples, [Co{S 2 CN( p -tolyl) 2 } 3 ] and [Co{S 2 CNPh( m -tolyl)} 3 ] being crystallographically characterised. Solvothermal decomposition of [Co{S 2 CN( p -tolyl) 2 } 3 ] in oleylamine generates phase pure CoS 2 nanospheres in an unexpected phase-selective manner.