Synthesis and structures of tris(2-pyridyl)aluminate sandwich compounds [{RAl(2-py')2}2M] (py' = 2-pyridyl, M = Ca, Mn, Fe).

Reactions of the lithium salts [{RAl(2-py')3Li·THF] [2-py' = 2-py (2-pyridyl), R = (n)Bu (1), R = (sec)Bu (2); py' = 5-Me-2-py (5-methyl-2-pyridyl), R = Me (3); 6-Me-2-py (6-methyl-2-pyridyl), R = Et (4b)] with the corresponding metal(ii) halides give the new heterobimetallic sandwich compounds [{RAl(2-py)3}2M] [R = (n)Bu, M = Ca (5), Mn (6), Fe (7); R = (sec)Bu, M = Ca (8), Mn (9)], [{MeAl(5-Me-2-py)3}2Ca] (10) and [{EtAl(6-Me-2-py)3}2Ca] (11) and the co-complex [{EtAl(6-Me-2-py)3}Mn(μ-Cl)Li{(6-Me-2-py)3AlEt}] (12). While neither the bridgehead group (R) nor remote ring Me-groups have any impact on metal coordination in 5-10, the introduction of Me groups into the pyridyl substituent at the 6-position (i.e.

Synergic anion and cation coordination using the tripodal aluminate anion [MeAl(2-py)(3)](-) (py = 2-pyridyl).

The coordination of AlCl(3) by the complex [{MeAl(2-py)(3)}Li.thf] () gives the unusual product [{MeAl(2-py)(3)}(2)Al](+)[{MeAl(2-py)(3)}Li](2)(mu-Cl)(-) (), in which the [MeAl(2-py)(3)](-) aluminate anion of acts cooperatively in the coordination of an Al(3+) cation and Cl(-) anion.

Metal and ligand substitution of the aluminium tris-pyridyl ligands [RAl(2-py')(3)](-) (R = Et, (n)Bu, (s)Bu, (t)Bu; 2-py' = 2-pyridyl, 3-methyl-2-pyridyl, 5-methyl-2-pyridyl, 6-methyl-2-pyridyl).

A series of tris-pyridyl complexes [RAl(2-py)(3)]Li.thf [2-py = 2-pyridyl; R = Et (1); (n)Bu (2); (s)Bu (3), (t)Bu (4)] were prepared by the sequential reaction of AlCl(3) with RLi then 2-Li-py in thf. The related complexes [MeAl{2-(3-Me)py}(3)]Li(mu-Br)Li(thf)(3) (5), [MeAl{2-(5-Me)py}(3)]Li.

The cationic cluster Grignard [{MgCl(thf)2}3(mu3-C3H5)2]+.

The synthesis and structure of [{MgCl(thf)2}3(mu3-C3H5)2]2[Mg(C3H5)4], which contains both a cationic cluster Grignard and a tetraorganomagnesiate dianion, are reported.