Solvothermal synthesis of [Cr-10(mu-O2CMe)(10)(mu-OR)(20)] 'chromic wheels' with antiferromagnetic (R = Et) and ferromagnetic (R = Me) Cr(III)center dot center dot center dot Cr(III) interactions

Two decanuclear cyclic Cr(iii) complexes have been synthesised in high yield by solvothermal techniques: magnetic susceptibility studies reveal ferromagnetic Cr . . . Cr exchange in one, and antiferromagnetic Cr . . . Cr exchange in the other.