摘要:
The reduction of neutral alpha-diimine ligands bearing different substituents on the N-aryl rings by different amounts of potassium metal and subsequent reaction with anhydrous MgCl2 in THF afforded a series of magnesium compounds, [(L-iPr)Mg2--(THF)(2)]center dot THF (2), [(L-Mes)Mg2-(THF)(3)] (3), [(L-iPr)(2)Mg-]center dot THF (4), [(L-Mes)(2)Mg-] (5), and [(L-Mes)(2)Mg2-(eta(6):eta(6)-K(THF)(2))][K(THF)(6)]center dot(THF)(2) (6) (L-iPr = [(2,6-(Pr2C6H3)-Pr-i)NC-(Me)](2)), L-Mes = [(2,4,6-Me3C6H2)NC(Me)](2)). Complexes 2-6 have been characterized by single-crystal X-ray diffraction, elemental analysis, NMR spectroscopy, and EPR studies (for 4 and 5). The noninnocent alpha-diimine ligands exist as the dianionic form in compounds 2, 3, and 6 and as a monoanion in 4 and 5. Effects of the ligand substituents and the amount of the reducing agent on the structure of the product have been discussed.