Divalent lanthanide complex classical

The non-classical divalent lanthanide complexes have stronger reducing power than divalent samarium complexes because of their higher reduction potentials. Dinitrogen is not an inert atmosphere for these non-classical divalent lanthanide complexes. Therefore, attempts to prepare non-classical divalent organolanthanide complexes by metathesis reactions in dinitrogen atmosphere have been unsuccessful, and the dinitrogen-activated products were isolated. A typical example is shown in Equation 8.36 [112]. 

Non-classical divalent lanthanide complexes, F. Nief, Dalton Transactions 2010, 39, 6589. 

The classical divalent organolanthanide complexes, mainly for Sm + and Yb +, have strong reducing potentials. They can reduce a series of transition metal carbonyls and AgBPh4 to give the cationic lanthanide complexes. 

Divalent lanthanide chemistry has been dominated by the most readily accessible divalent lanthanide metals samarium(II), europium(II), and ytterbium(II) (classical ) for decades, and a large number of divalent lanthanide compounds have been prepared [92], There are three routes to generate divalent organolanthanide complexes oxidative reaction of lanthanide metal, metathesis reaction of a divalent lanthanide halide, and reductive reaction of a trivalent lanthanide complex. 

Tml2(DME)3, Dyl2 (DME)3, and Ndl2(THF)5 have similar structures to those of the classical divalent lanthanide iodides. However, metathesis reaction with these iodides usually affords not a divalent complex but a trivalent lanthanide complex instead, because of their strong reductive ability [102], To date, only one structurally characterized divalent organothulium complex has been synthesized by metathesis reaction (Equation 8.34) [104]. 

This review covers all organometallic complexes of Sc, Y and the lanthanides reported in the year 2000 and their reactions. Endohedral fullerene complexes of the lanthanides have, as usual, been excluded. Highlights this year include striking reports of lanthanides in non-classical oxidation states (Sections 3.2 and 5), a remarkable reversible dinitrogen activation described in Section 3.9.2 and evidence for the existence of the divalent hydrides LnH2(THF)2 (Ln = Sm, Yb) (Section 3.10). In addition Evans has assessed the utility of electrospray mass spectrometry for the characterization of organolathanides. The results are promising and the spectra and dissociation patterns show sensitivity to the metal and its oxidation state. ... 

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