Assembly of metal complexes

The reactions of silver(I) hexafuluorophosphate with imino nitroxyl diradic als 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'-tet ramethyl-4',5'-dihydro-1'H-imidazol-2'-yl)pyridazine) and bpy-im2 = 2,2'-bi s(1'-oxyl-4',4',5', 5'-tetramethyl-4',5'-dihydro-1'H-imidazol-2'-yl)bipyrid ine)). Compelxes 1 and 2 have four radicals being double-helically assemble d by the coordination to the silver ions. Magnetic susceptibility measureme nts 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 under stood by the spin polarization mechanism. The reaction of MnSO4. 4H(2)O wit h K2CrO4 in water yielded highly crystalline black 3. X-ray crystallographi c 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). Mag netic susceptibility measurement reveals that the antiferromagnetic interac tions are operative without antiferromagnetic ordering and the exchange cou pling constant was estimated to be -1.4 cm(-1).