000202988 001__ 202988
000202988 005__ 20181203023645.0
000202988 0247_ $$2doi$$a10.1039/c2sc20476b
000202988 022__ $$a2041-6520
000202988 02470 $$2ISI$$a000305900700004
000202988 037__ $$aARTICLE
000202988 245__ $$aMultielectron redox chemistry of lanthanide Schiff-base complexes
000202988 260__ $$c2012
000202988 269__ $$a2012
000202988 336__ $$aJournal Articles
000202988 520__ $$aMultielectron redox chemistry, which is essential in metal catalysed chemical transformations, is not easily accessible in lanthanide complexes. Here we explored the reductive chemistry of lanthanide complexes with tetradentate Schiff bases acting as redox-active ligands with the objective of identifying new pathways to lanthanide multielectron redox transfer. The chemical reduction with alkali metals of heteroleptic [Nd(salophen)X] (salophen = N,N′-bis(salicylidene)phenylenediamine, X = I, OTf) and of a series of homoleptic K[Ln(Rsalophen)2] complexes of trivalent lanthanides has resulted respectively in the synthesis of the new dinuclear Nd(iii) complex K2[Nd2(cyclo-salophen)(THF)2] and in the synthesis of a series of mononuclear lanthanide(iii) complexes of general formula K3[Ln(bis-Rsalophen)] (R = H, Me, tBu). Ligand reduction and C-C bond formation are supported by X-ray crystal structures. Proton NMR studies demonstrate that the K2[Nd 2(cyclo-salophen)(py)2] complex can transfer four electrons in the reaction with oxidizing agents such as AgOTf through the breaking of the two C-C bonds. Moreover the electrochemistry and reactivity of the mononuclear complexes K3[Ln(bis-Rsalophen)] show that they can act as formal two electron reductants and that their oxidation potential can be tuned by changing the substituents on the ligand. These results illustrate that Schiff bases provide a new way to introduce multielectron redox events at lanthanide centers and a new route to highly reactive mono- and polynuclear complexes of lanthanides. © The Royal Society of Chemistry 2012.
000202988 700__ $$aCamp, Clement
000202988 700__ $$aGuidal, Valentin
000202988 700__ $$aBiswas, Biplab
000202988 700__ $$aPecaut, Jacques
000202988 700__ $$aDubois, Lionel
000202988 700__ $$0248440$$aMazzanti, Marinella$$g166619
000202988 773__ $$j3$$k8$$q2433-2448$$tChemical Science
000202988 909C0 $$0252515$$pGCC$$xU12966
000202988 909CO $$ooai:infoscience.tind.io:202988$$pSB$$particle
000202988 917Z8 $$x249835
000202988 937__ $$aEPFL-ARTICLE-202988
000202988 973__ $$aOTHER$$rREVIEWED$$sPUBLISHED
000202988 980__ $$aARTICLE