Reduction of Digallane [(dpp‐bian)GaGa(dpp‐bian)] with Group 1 and 2 Metals

Abstract

The reduction of digallane [(dpp-bian)Ga-Ga(dpp-bian)] (1) (dpp-bian=1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with lithium and sodium in diethyl ether, or with potassium in THF affords compounds featuring the direct alkali metal-gallium bonds, [(dpp-bian)Ga-Li(Et(2)O)(3)] (2), [(dpp-bian)Ga-Na(Et(2)O)(3)] (3), and [(dpp-bian)Ga-K(thf)(5)] (7), respectively. Crystallization of 3 from DME produces compound [(dpp-bian)Ga-Na(dme)(2)] (4). Dissolution of 3 in THF and subsequent crystallization from diethyl ether gives [(dpp-bian)Ga-Na(thf)(3)(Et(2)O)] (5). Ionic [(dpp-bian)Ga](-)[Na([18]crown-6)(thf)(2)](+) (6a) and [(dpp-bian)Ga](-)[Na(Ph(3)PO)(3)(thf)](+) (6b) were obtained from THF after treatment of 3 with [18]crown-6 and Ph(3)PO, respectively. The reduction of 1 with Group 2 metals in THF affords [(dpp-bian)Ga](2)M(thf)(n) (M=Mg (8), n=3; M=Ca (9), Sr (10), n=4; M=Ba (11), n=5). The molecular structures of 4-7 and 11 have been determined by X-ray crystallography. The Ga-Na bond lengths in 3-5 vary notably depending on the coordination environment of the sodium atom.