Pyrimidyl-2-selenolates of cadmium and mercury: Synthesis, characterization, structures and their conversion to metal selenide nano-particles

Reactions of [MCl2(tmeda)] (M = Cd or Hg; tmeda = N,N,N′,N′-tetramethylethylenediamine) with NaSeC4H(R-4,6)2N2 (R = H or Me) gave selenolate complexes of the general formula [M{SeC4H(R-4,6)2N2}2(tmeda)n] (M/R/n = Cd/H/1 (1); Cd/Me/1 (2); Hg/H/1 (3) and Hg/Me/0 (4)). The chloro complexes of general formula, [MCl{SeC4H(Me-4,6)2N2}(tmeda)] (M = Cd (6) or Hg (7)) have been synthesized by redistribution reaction of [M{SeC4H(Me-4,6)2N2}2] with MCl2 followed by treatment with tmeda. The complexes have been characterized by elemental analysis, UV–Vis and NMR (1H, 13C, 77Se, 113Cd and 199Hg) spectroscopy. The molecular structures of [Cd{SeC4H(Me-4,6)2N2}2(tmeda)] and [Hg{SeC4H(Me-4,6)2N2}2] were established by single crystal X-ray diffraction. The complex, [Cd{SeC4H(Me-4,6)2N2}2(tmeda)] comprises of an octahedral cadmium atom containing chelating, two SeC4H(4,6-Me)N2 and one tmeda, ligands. The complex, [Hg{SeC4H(Me-4,6)2N2}2] has a linear structure with monodentate selenolate ligand. Thermolysis of [Cd{SeC4H(Me-4,6)2N2}2(tmeda)] and [Hg{SeC4H(Me-4,6)2N2}2] in various coordinating solvents afforded CdSe and HgSe nanoparticles which were characterized by UV–Vis, XRD, SEM, EDX and TEM.