SYNTHESIS AND CHARACTERIZATION OF THE STRONTIUM THIOLATE SR(SMES-ASTERISK)(2)(THF)(4).2THF (MES-ASTERISK=2,4,6-TBU(3)C(6)H(2)) AND SELENOLATE SR(SEMES-ASTERISK)(2)(THF)(4).2THF - STRUCTURAL INVESTIGATION OF SRI2(THF)(5)

The syntheses and structural characterization of the strontium thiolat e Sr(SMes)(2)(THF)(4) . 2THF, 1 (Mes* = 2,4,6-tBu(3)C(6)H(2)), and se lenolate Sr(SeMes)(2)(THF)(4) . 2THF, 2, are described. We also repor t the synthesis and structural characterization of SrI2(THF)(5), 3, th e apparent starting material for the synthesis of 1 and 2. 3 exhibits pentagonal bipyramidal geometry at the strontium atom. 3 can be prepar ed by dissolving SrI2 in THF, while the treatment of 3 with 2 equiv of the sterically demanding potassium thiolate and selenolate in THF aff ords 1 and 2 in good yields. 1 and 2 exhibit distorted octahedral envi ronments at the metal center, with the degree of distortion much more significant for the thiolato derivative. 1 and 2 were characterized by H-1 NMR and IR spectroscopy, elemental analysis, and X-ray crystallog raphy; 3 was characterized by single-crystal structure analysis. Cryst al data with Mo K alpha (lambda = 0.71073 (Angstrom A) at 213 K are as follows. 1: a = 18.535(4) Angstrom A, b = 19.222(4) Angstrom A, c 18. 775(4) Angstrom A, beta = 107.30(3)degrees, V = 6387(2) Angstrom A(3), Z = 4, monoclinic, space group I2/a, 2254 (I > 3 sigma(I)) data, R = 0.071. 2: a = 18.330(4) Angstrom A, b = 19.498(4) Angstrom A, c = 18.6 08(4) Angstrom A, beta 105.52(3)degrees, V = 6408(3) Angstrom A(3) Z = 4, monoclinic, space group I2/a, 2331 (I > 3 sigma(I)) data, R = 0.05 7. 3: a 8.851(1) Angstrom A, c = 35.353(7) Angstrom A, V = 2770(1) Ang strom A(3), Z = 4, tetragonal, space group P4(3)2(1)2, 939 (I > 3 sigm a(I)) data, R = 0.069.