Abstract
Three new main group ferrocenyldithiocarbamate complexes, viz., {Pb[(FcCH(2))(CH2CH2OH)(NCS2)](2)}center dot(FcCH(2)-3-oxazolidine-2-thione)center dot(H2O) (1), {Sb[(FcCH(2))(CH2CH2OH)(NCS2)](3)} (2) and {Bi[(FcCH(2))(CH2CH2OH)(NCS2)](3)} (3), (Fc = ferrocenyl) have been synthesized and characterized by elemental analyses and IR, H-1 and C-13 NMR spectroscopy as well as X-ray crystallography. The X-ray analysis of 1 indicates distorted trigonal bipyramidal geometry around Pb(ii) and a cyclised product, 3-ferrocenylmethyl-oxazolidine-2-thione (4), co-crystallizes with 1. The geometry around Sb(iii) in 2 is pseudo-octahedral, while 3 forms a dimer, displaying distorted square antiprism geometry around the Bi(iii) center. Several attempts to synthesize the pure cyclised product 3-ferrocenylmethyl-oxazolidine-2-thione (4) using Pb(ii) salts failed but 4 was fortuitously obtained in an attempt to synthesize the Cu(i) cluster by the comproportionation of {Cu[(FcCH(2))(CH2CH2OH)(NCS2)](2)} using copper powder. Interestingly, varying the reaction time yielded another completely desulfurized cyclised product 3-ferrocenylmethyl-oxazolidine-2-one (5). Both 4 and 5 have been characterized using spectroscopic techniques and X-ray crystallography, and the possible mechanism for the conversion of {Cu[(FcCH(2))(CH2CH2OH)(NCS2)](2)} to 3-ferrocenylmethyl-oxazolidine-2-thione (4) has been explained with the help of periodic UV-Vis and ESI-MS experiments. This investigation will pave a new pathway for the synthesis of similar cyclised products using similar safe and sustainable reaction conditions.