ic202505d_si_002.cif (319.99 kB)
Divalent Lanthanide Complexes Supported by the Bridged Bis(amidinates) L [L = Me3SiN(Ph)CN(CH2)3NC(Ph)NSiMe3]: Synthesis, Molecular Structures and One-Electron-Transfer Reactions
dataset
posted on 2012-04-02, 00:00 authored by Lijuan Yan, Haidong Liu, Junfeng Wang, Yong Zhang, Qi ShenMetathesis reactions of YbI2 with Li2L (L
= Me3SiN(Ph)CN(CH2)3NC(Ph)NSiMe3) in THF at a molar ratio of 1:1 and 1:2 both afforded the
Yb(II) iodide complex [{YbI(DME)2}2(μ2-L)] (1), which was structurally characterized
to be a dinuclear Yb(II) complex with a bridged L ligand. Treatment
of EuI2 with Li2L did not afford the analogous
[{EuI(DME)2}2(μ2-L)], or another
isolable Eu(II) complex, but the hexanuclear heterobimetallic cluster
[{Li(DME)3}+]2[{(EuI)2(μ2-I)2(μ3-L)2(Li)4}(μ6-O)]2– (2) was isolated as a byproduct in a trace yield. The rational
synthesis of cluster 2 could be realized by the reaction
of EuI2 with Li2L and H2O in a molar
ratio of 1:1.5:0.5. The reduction reaction of LLnCl(THF)2 (Ln = Yb and Eu) with Na/K alloy in THF gave the corresponding Ln(II)
complexes [Yb3(μ2-L)3] (3) and [Eu(μ2-L)(THF)]2 (4) in good yields. An X-ray crystal structure analysis revealed
that each L in complex 3 might adopt a chelating ligand
bonding to one Yb atom and each Yb atom coordinates to an additional
amidinate group of the other L and acts as a bridging link to assemble
a macrocyclic structure. Complex 4 is a dimer in which
the two monomers [Eu(μ2-L)(THF)] are connected by
two μ2-amidinate groups from the two L ligands. Complex 3 reacted with CyNCNCy and diazabutadienes
[2,6-iPr2C6H3NCRCRNC6H3iPr2-2,6] (RH, CH3)
(DAD) as a one-electron reducing agent to afford the corresponding
Yb(III) derivatives: the complex with an oxalamidinate ligand [LYb{(NCy)2CC(NCy)2}YbL] (5) and the complexes
containing a diazabutadiene radical anion [LYb(iPr2C6H3NCRCRNC6H3iPr2)] (R = H
(6), R = CH3 (7)). Complexes 5–7 were confirmed by an X-ray structure
determination.