Abstract
An α-diimine-stabilized Al-Al-bonded compound [L 2-Al II-Al IIL 2-] (L=[{(2,6-iPr 2C 6H 3)NC(Me)} 2]; 1) consists of dianionic α-diimine ligands and sub-valent Al 2+ ions and thus could potentially behave as a multielectron reductant. The reactions of compound 1 with azo-compounds afforded phenylimido-bridged products [L -Al III(μ 2-NPh)(μ 2-NAr)Al IIIL -] (2-4). During the reaction, the dianionic ligands and Al 2+ ions were oxidized into monoanions and Al 3+, respectively, whilst the [NAr] 2- imides were produced by the four-electron reductive cleavage of the N=N double bond. Upon further reduction by Na, the monoanionic ligands in compound 2 were reduced to the dianion to give [(L 2-) 2Al III 2(μ 2-NPh) 2Na 2(thf) 4] (5). Interestingly, when asymmetric azo-compounds were used, the asymmetric adducts were isolated as the only products (compounds 3 and 4). DFT calculations indicated that the reaction was quite feasible in the singlet electronic state, but the final product with the triplet-state monoanionic ligands could result from an exothermic singlet-to-triplet conversion during the reaction process.
Original language | English |
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Pages (from-to) | 6022-6030 |
Number of pages | 9 |
Journal | Chemistry - A European Journal |
Volume | 18 |
Issue number | 19 |
DOIs | |
Publication status | Published - 7 May 2012 |
Externally published | Yes |
Keywords
- aluminum
- azo compounds
- cleavage reactions
- reaction mechanisms
- reduction