Synthesis and structure of bis(thiomethyl)magnesium compounds [Mg(CH2SR)2(thf)3] (R = Me, Ph) - the first dimethylmagnesium compounds functionalized by a Lewis-basic heteroatom
摘要:
Hg(CH2SR)(2), (R = Me (1), R = Ph (2)), prepared by reaction of HgCl2 with [Li-2(CH2SR)(2)(tmeda)(2)], reacts with magnesium activated by mercury in boiling THF to give [Mg(CH2SR)(2)(thf)(3)] (R = Me (3), R = Ph (4)). 3 readily splitts off THF in vacuo to give the solvate free complex [Mg(CH2SMe)(2)] (3'). The complexes 3' and 4 are fully characterized by microanalysis and NMR spectroscopy (H-1, C-13).The X-ray structure analyses of 3 and 4 reveal mononuclear compounds with two symmetry independent molecules in the unit cell of 3. In both complexes the coordination of Mg is trigonal-bipyramidal. The two apical positions are occupied by THF and the three equatorial positions by one THF and the two thiomethyl ligands. The C-Mg-C angles are slightly greater (123.9(1)-131.0(2)degrees) than the ideal angle for equatorial atoms in a trigonal-bipyramidal coordination. In neither case, the sulfur atoms are involved in the coordination of Mg. (C) 1998 Elsevier Science Ltd. All rights reserved.