SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF MONOMERIC SELENOLATO COMPLEXES OF ZINC, CADMIUM, AND MERCURY

The synthesis and characterization of homoleptic zinc(TI), cadmium(II) , and mercury(II) selenolates incorporating the intramolecularly chela ting oxazoline ligand are described. The derivatives, M[Se(Ox)](2) [M = Zn (1), Cd (2), Hg (3); Ox = 2-(4,4-dimethyl-2-oxazolinyl)benzene], were prepared in good yield via the metathesis reactions of MCl2 with a lithium areneselenolate, OxSe(-)Li(+). The mercury complex 3 was als o synthesized by treating the corresponding diselenide with elemental mercury. The complexes are quite stable and highly soluble in common n onpolar organic solvents. X-ray diffraction results show that the comp lexes are monomeric in the solid state. The geometry around the metal ion in all complexes is found to be distorted tetrahedral. The crystal structure of Zn[Se(Ox)](2) (1) shows that the complex is ''helically' ' chiral and enantiomerically pure. The spontaneous splitting ng of th e racemates indicates the solubility differences between the racemates and pure enantiomers. H-1, C-13, and Se-77 NMR measurements indicate that complex 1 retains its ''helical'' structure in solution. Crystal data (Mo Kcl; 293(2) K) are as follows: 1, monoclinic space group P2(1 ), a = 9.3900(12) Angstrom, b = 11.618(2) Angstrom, c = 10.8822(14) An gstrom, beta = 98.245(8)degrees, Z = 2; 2, orthorhombic space group Pb ca, a = 12.777(6) Angstrom, b = 17.841(10) Angstrom, c = 21.010(8) Ang strom, Z = 8; 3, monoclinic space group P2(1)/c, a = 9.087(2) Angstrom , b = 11.889(2) Angstrom, c = 22.456(4) Angstrom, beta = 98.780(13)deg rees, Z = 4.