The reactions of silver(I) hexafuluorophosphate with imino nitroxyl diradicals yield complexes of [Ag-2(pyrd-im2)(2)](PF6)(2). 2CH(3)OH (1) and [Ag-2(bpy-im2)(2)](PF6)(2). CH3OH (2) (pyrd-im2 = 3,6-bis(1'-oxyl-4',4',5',5'-tetramethyl-4',5'-dihydro-1'H-imidazol-2'-yl)pyridazine) and bpy-im2 = 2,2'-bis(1'-oxyl-4'.4',5',5'-tetramethyl-4',5'-dihydro-1'H-imidazol-2'-yl)bipyridine)). Compelxes 1 and 2 have four radicals being double-helically assembled by the coordination to the silver ions. Magnetic susceptibility measurements revealed a strong antiferromagnetic interaction (-70.8(7) cm with H = 2JS(1).S-2) in 1 being operative through the pyridazine group, which was understood by the spin polarization mechanism. The reaction of MnSO4. 4H(2)O with K2CrO4 in water yielded highly crystalline black 3. X-ray crystallographic study revealed that 3 has the chemical formula K[Mn-2(mu -CrO4)(2)(mu -OH)(2)], which implies that the manganese ions are mixed valent Mn(II,III). Magnetic susceptibility measurement reveals that the antiferromagnetic interactions are operative without antiferromagnetic ordering and the exchange coupling constant was estimated to be -1.4 cm(-1).