title: Synthesis and structures of mononuclear and dinuclear gallium complexes with α-diimine ligands: reduction of the metal or ligand?
abstract: Reduction of the dichloro gallium(III) α-diimine complex [(L(ipr))˙(-)GaCl2] (1, L(ipr) = [(2,6-iPr2C6H3)NC(Me)]2) by different equivalents of sodium metal afforded the gallium complexes [(L(ipr))(2-)Ga(III)(μ2-Cl)2Na(THF)4] (2) and [(Na(THF)6)(+)·((L(ipr))(2-)Ga-Ga(L(ipr))(2-))˙(-)] (3). Interestingly, in complex 2 a Na(+)Cl(-) ion pair is incorporated, while compound 3 is an anionic digallium complex. Moreover, a cationic gallium complex with a tetrachlorogallium(III) counter anion, [(LGaCl2)(+)·(GaCl4)(-)] (4), was accessed from the reaction of GaCl3 with 0.5 equiv. of ligand L(ipr). In contrast, the reaction of GaCl3 with the doubly reduced anion (Na2L(2-)) of the smaller α-diimine ligands L(Me) ([(2,6-Me2C6H3)NC(Me)]2) or L(Et) ([(2,6-Et2C6H3)NC(Me)]2) yielded the Ga-Ga-bonded complexes [(L(Et))˙(-)ClGa(II)-Ga(II)Cl(L(Et))˙(-)] (5) and [(L(Me))˙(-)ClGa(II)-Ga(II)Cl(L(Me))˙(-)] (6). Here L is the neutral α-diimine ligand, L˙(-) represents the monoanion, and L(2-) is the dianionic form of the ligand. The complexes were characterized by X-ray diffraction and their electronic structures were studied by DFT computations.
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, China. zhaoyx@nwu.edu.cn.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, China. zhaoyx@nwu.edu.cn.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Center for Computational Quantum Chemistry, South China Normal University, Guangzhou 510631, China.
authors.forename: Qian-Shu
authors.initials: QS
authors.lastname: Li
authors.affiliation: Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Ji-Hu
authors.initials: JH
authors.lastname: Su