Synthesis and structures of some heterometallic [(Li, Y)2, (M3, Ce) (M= Lior Na), (Li, Zr2) and (Li, Zr)4] oligomeric diamides derived from1,2-bis(neopentylamino)benzene
The following crystalline, X-ray-characterised heterometallic oligomeric diamides have been prepared
in good yield under mild conditions in diethyl ether from the dilithio or disodio derivative of the
N,N-dineopentyl-1,2-diaminobenzene [{N(H)(CH2But)}2C6H4-1,2] (abbreviated as H2L):
[Y(L)(l-Cl)2Li(OEt2)2]2 (1), [Li(OEt2)2Li(l2-Cl)4(l3-Cl)2{Zr(L)}2]2 (2), [Zr(L)2(l-Cl)-
{Li(OEt2)2}(l2-Cl)2Zr(L)] (3), [Ce{(l-L)M}3(OEt2)1/2] (3M= Li1.82Na1.18) (4), [Ce{(l-L)Na}3(OEt2)] (5)
and [Ce{(l-L)Na}3] (6). Compounds 1–3 were obtained from Li2(L) andYCl3 (the colourless 1) or
ZrCl4 (the red 2 and 3), while the red 4 and 5 were isolated from CeCl3 andM2(L) (3M= Li1.82Na1.18) (4)
or Na2(L) (5). Attempted oxidation of 5 with Br2 in hexane yielded the black 6. The ligand L is
N,N-chelating to each of the d- or f-block metals in 1–6; and in 4–6 L is also acting as a bridge between
Ce and the alkali metal, to which L is thus also chelating.
Dalton Trans., 2006, 2991–2997