Syntheses and 1H, 13C, 15N, 17O, 205Tl NMR of new ring-functionalised chelating half-sandwich complexes of thallium(I) containing an N-, O- or S-donor atom

Novel, ring-functionalised cyclopentadienylthallium(I) complexes have been synthesised in good to moderate yields from thallium ethoxide and N-, O- and S-alkyl substituted cyclopentadienes in diethyl ether at 0 degrees C. The new compounds have been analysed by H-1, C-13, N-15, O-17 and Tl-205 NMR, which revealed that cyclopentadienyl ring and the donor atom in the side chain are coordinated to thallium; they are mononuclear complexes. Hence, these compounds can be viewed as analogues of their parent, CpTl, but their solubility is much enhanced because of the mononuclear nature due to the presence of the side chain. The thallium(I) complexes with the (dimethylamino) ethyl, methoxyethyl and (methylsulfanyl) ethyl side chain are promising reagents for transmetallation reactions.