“GaI”与双（亚氨基）吡啶配位中的歧化和自由基形成。

Disproportionation and radical formation in the coordination of "GaI" with bis(imino)pyridines.

机构信息

Centre for Catalysis Research and Innovation and Department of Chemistry, University of Ottawa, Ottawa, Ontario, K1N 6N5.

出版信息

Dalton Trans. 2010 Feb 7;39(5):1266-72. doi: 10.1039/b920047a. Epub 2009 Nov 24.

DOI:10.1039/b920047a

PMID:20104353

Abstract

Attempted coordination of "Ga(I)I" with two new sterically bulky, aryl substituted bis(imino)pyridine ligands lead to Ga(III) species [2,6-{ArN=CPh}(2)(NC(5)H(3))]GaI(2)(+)GaI(4)(-) (Ar = 2,5-(t)Bu(2)C(6)H(3), 2,6-(i)Pr(2)C(6)H(3) = Dipp) arising from thermodynamically favorable disproportionation reactions. Examination of these reactions lead to isolation of a neutral radical species [2,6-{DippN=CPh}(2)(NC(5)H(3))]GaI(2). Both EPR spectroscopy and DFT calculations on this compound indicate that the unpaired electron is localized in a di(imino)pyridine pi* orbital of an anionic ligand with nearly zero contribution from the Ga or I centers. Reaction of {2,5-(t)Bu(2)C(6)H(3)N=CPh}(2)(NC(5)H(3)) with AlCl(3) yielded an analogous Al(iii) product, [{2,5-(t)Bu(2)C(6)H(3)N=CPh}(2)(NC(5)H(3))]AlCl(2)(+)AlCl(4)(-).

摘要

试图用两个新的空间位阻大的芳基取代双（亚氨基）吡啶配体来协调“Ga(I)I”，导致 Ga(III)物种 [2,6-{ArN=CPh}(2)(NC(5)H(3))]GaI(2)(+)GaI(4)(-)（Ar = 2,5-(t)Bu(2)C(6)H(3, 2,6-(i)Pr(2)C(6)H(3) = Dipp) 出现，这是热力学有利的歧化反应的结果。对这些反应的研究导致分离出中性自由基物种 [2,6-{DippN=CPh}(2)(NC(5)H(3))]GaI(2)。该化合物的电子顺磁共振波谱和密度泛函理论计算表明，未成对电子定域在阴离子配体的二（亚氨基）吡啶 pi*轨道中，几乎没有来自 Ga 或 I 中心的贡献。{2,5-(t)Bu(2)C(6)H(3)N=CPh}(2)(NC(5)H(3))与 AlCl(3)反应生成类似的 Al(iii)产物 [{2,5-(t)Bu(2)C(6)H(3)N=CPh}(2)(NC(5)H(3))]AlCl(2)(+)AlCl(4)(-)。