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[求助]
求翻译一段(化学化工范畴)
In 1975, Gillard postulated an important covalent hydrate (CH) mechanism to rationalize the “anomalies” in the reactions of this kind of metal complexes, and the core of which is that the metal ligation to a pyridyl or 2,2′-bpy-like ligand leads to electronic changes in the pyridyl ring, thus enhancing nucleophilic attack of a hydroxide ion on the 2-position of a pyridine or phen (or the 6-position of 2,2′-bpy) ligand to form a CH (see Scheme 3) before further intramolecular shift of OH -or H2O onto the metal to form the final hydrolyzed or other related products.Unfortunately, this important mechanism became a long-term debate due to
the lack of structural evidence for the CH intermediate. In 2002, we provided the key structural evidence for the Gillard mechanism by the isolation of 2-hydroxylated phen (and 6-hydroxylated 2,2′-bpy) ligands (see Scheme 1c,d)in their dinuclear CuIand tetranuclear CuI-CuII complexes, such as [Cu2(ophen)2](4) and [Cu4(ophen)2(tp)] (5) [ophen)1,10-phenanthrolin-2(1H)-one; tp)terephthalate] (Figure 2), from the solvothermal reactions of CuII salt with phen or 2,2′-bpy.The formation of4can be proposed with the aid of the CH mechanism to be via the formation of CH and related intermediates (Scheme 3),followed by dimerization, intramolecular electron transfer, and dehydrogenation, while one- while one-electron oxidization of
4and bridging of a tp furnishes5
![求翻译一段(化学化工范畴)]()
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[ Last edited by greenhand_ku on 2015-2-10 at 10:02 ] |
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