Two Novel Cyanide-Bridged Bimetallic Magnetic Chains Derived from Manganese(III) Schiff Bases and Hexacyanochromate(III) Building Blocks

Two novel complexes, [{Mn(salen)}(2){Mn(salen) (CH3OH)) {Cr(CN)(6)}](n)center dot 2nCH(3)CN center dot nCH(3)OH (1) and [Mn(5-Clsalmen)(CH3OH)(H2O)](2n)[Mn(5-Clsalmen)(mu-CN)}Cr (CN)(5)](n)center dot 5.5nH(2)O (2) (salen(2-) = N,N'-ethylene-bis(salicylideneiminato) dianion; 5-Clsalmen(2-) = N,N'-(1-methylethylene)-bis(5-chlorosalicylideneiminato)dianion), were synthesized and structurally characterized by X-ray single-crystal diffraction. The structural analyses show that complex I consists of one-dimensional (ID) alternating chains formed by the [{Cr(CN)(6)} {Mn(salen)}(4){Mn(salen)(CH3OH)}(2)(3+) heptanuclear cations and [Cr(CN)(6)](3+) anions. While in complex 2, the hexacyanochromate(H) anion acts as a bis-monodentate ligand through two trans-cyano groups to bridge two-[Mn(5-Clsalmen)](+) cations to form a straight chain. The Magnetic analysis indicates that complex I shows three-dimensional (3D) anti-ferromagnetic ordering with the Neel temperature of 5.0 K, and it is a metamagnet displaying antiferromagnetic to ferromagnetic transition at a critical field of about 2.6 kOe at 2 K. Complex 2 behaves as a molecular magnet with Tc = 3.0 K