R. Andres et al., Rational design of three-dimensional (3D) optically active molecule-based magnets: Synthesis, structure, optical and, magnetic properties of {[Ru(bpy)(3)](2+), ClO4-, [(MnCrIII)-Cr-II(ox)(3)](-)}(n) and {[Ru(bpy)(2)ppy](+), [(MCrIII)-Cr-II(ox)(3)](-)}(n), with M-II = Mn-II, Mn-II. X-ray structure of {[Delta Ru(bpy)(3)](2+), ClO4-, [Delta Mn-II Delta Cr-III(ox)(3)](-)}(n) and {[Lambda Ru(bpy)(2)ppy](+), [Delta Mn-II Lambda Cr-III(ox)(3)](-)}(n), INORG CHEM, 40(18), 2001, pp. 4633-4640
To elucidate the relation between structural and magnetic properties, we ha
ve synthesized molecular materials having both Cotton effects and a ferroma
gnetic long range order. Such optically active 3D molecule-based magnets we
re rationally designed using the enantioselective template effect of optica
lly active cations, namely A or A [Ru(bpy)(3), ClO4](+) or Delta or Delta [
Ru(bpy)(3)ppy](+) (bpy = bipyridine; ppy = phenylpyridine). Such cations ar
e able to template the formation of optically active 3D anionic networks in
which transition metal ions (Cr Mn) and (Cr-Ni) are connected by oxalate l
igands (ox). Following this strategy, we described the synthesis of {[Ru-(b
py)(3)](2+), ClO4-, [(MnCrIII)-Cr-II(ox)(3)](-)}(n), and {[Ru(bpy)(2)ppy](), [(MCrIII)-Cr-II(ox)(3)](-)}(n), with M-II = Mn-II, Ni-II in their optica
lly active forms. In these 3D networks, all of the metallic centers have th
e same configuration, A or A, as the template cation. We have determined th
e structure of {[Delta Ru(bpy)(3)][ClO4][Delta Mn Delta Cr(ox)(3)]}(n), and
{[Lambda Ru(bpy)(2)ppy](+), [Lambda Mn(II)Lambda Cr-III(ox)(3)](-)}(n), by
X-ray diffraction studies. These optically active networks show the Cotton
effect and long-range ferromagnetic order at low temperatures. The magneti
c circular dichroism of {[Ru(bpy)(3)](2+), ClO4-, [(MnCrIII)-Cr-II(ox)(3)](
-)}(n), at 2 K is reported.