Formation of separated versus contact ion triplets in magnesium thiolates.Synthesis and characterization of [Mg(15-crown-5)(SCPh3)(2)] and [Mg(15-crown-5)(THF)2][S-2,4,6-tBu(3)C(6)H(2))](2)

The synthesis and structural characterization of two magnesium thiolate com plexes are described. Both compounds were prepared by analogous reactions r outes, namely, alkane elimination and transamination, but using differently sized ligands. Utilization of the smaller HSCPh3, resulted in the formatio n of [Mg(15-crown-5)(SCPh3)(2)], 1, displaying a seven-coordinate magnesium center with two magnesium-sulfur bonds. Employment of the sterically more encumbered HS-2,4,6-tBu(3)C(6)H(2) yielded a separated cation and anions as displayed in [Mg(15-crown-5)(THF)(2)] [S-2,4,6-tBu(3)C(6)H(2)](2), 2. Comp ound 2 exhibits a seven-coordinate cation, completing its coordination envi ronment with five metal-crown-ether interactions in addition to two tetrahy drofuran (THF) contacts. The compounds were characterized by IR and NMR spe ctroscopy in addition to X-ray crystallography. Crystal data with Mo K alph a (lambda = 0.71073 Angstrom) are as follows: 1, C48H50MgO5S2, a = 8.4785(4 ) Angstrom, b = 9.3595(5) Angstrom, c = 13.8306(6) Angstrom, alpha = 87.332 (1)degrees, beta = 85.929(1)degrees, gamma = 68.733(1)degrees, Z = 1, tricl inic; 2, C54H94MgO7S2, a = 13.6755(2) Angstrom, b = 12.8045(6) Angstrom, c = 32.7127(12) Angstrom, beta = 97.87(1)degrees, Z = 4, monoclinic.