SYNTHESIS AND CHARACTERIZATION OF NEW THIOLATO DERIVATIVES OF LITHIUM, MAGNESIUM, AND ZINC - EXAMPLES OF 2-COORDINATE LITHIUM AND ZINC SPECIES LIGATED BY SULFUR

The synthesis and characterization of new thiolato derivatives of lithium, magnesium, and zinc are described. Treatment of HSC6H3-2,6-Mes(2) in Et(2)O with 1 equiv of n-BuLi affords the asymmetric lithium thiolate dimer [{LiSC6H3-2,6-Mes(2)}(2)(Et(2)O)(2)] (1), in which only one of the Li+ ions is solvated by ethers, the other being solvated by thiolates alone. The addition of 2 equiv of thiol to MgR(2) (R n-Bu, s-Bu) produces the magnesium thiolate Mg(SC6H3-2,6-Mes)(2) (2), which probably has a monomeric structure in solution. Similarly, treatment of Zn{N(SiMe(3))(2)}(2) in hexane with 2 equiv of the bulky thiol HSC6H3-2,6-Mes(2) gives a monomeric zinc thiolate Zn(SC6H3-2,6-Mes(2))(2) (3). Two-coordinate environments, in which a lithium in I and zinc in 3 are coordinated by two thiolate sulfurs, have been confirmed by X-ray analysis. Both 1 and 3 also exhibit weak metal-ligand interactions involving the ortho mesityl group(s) of the thiolate ligand. Ah compounds were characterized by IR and H-1 NMR spectroscopy. Crystal data with Mo K alpha (lambda = 0.710 73 Angstrom) radiation at 130 K: 1, [{LiSC6H3-2,6-Mes(2)}(2)(Et(2)O)(2)], a = 10.948(2) Angstrom, b = 16.765(3) Angstrom, c = 28.081(6) Angstrom, beta = 97.67(3)degrees, monoclinic, Z = 4, space group P2(1)/c, R = 0.063; 3, Zn(SC6H3-2,6-Mes(2))(2), a = 16.840(5) Angstrom, b = 14.371(3) Angstrom, c = 18.253(6) Angstrom, beta = 114.15(2)degrees, monoclinic, Z = 4, space group P2(1)/c, R = 0.050.