A new family of polynuclear clusters containing the (Fe3MII)-M-III cores [(Tp(4BO))(6)Fe-6(CN)(18)M2Na2(H2O)(16)]center dot 4H(2)O (M = CU, Co, Mn; 1-3) and [(Tp(4Bo))(6)Fe-6(CN)(18)M2Na2(H2O)(12)(DMF)(4)]center dot H2O (M = CU, Co, Mn; 4-6) have been synthesized and structurally characterized. Complexes 1-3 crystallize in the P2(1)/c space roup, and 4-6 crystallize in the P2(1)/n space group. All six complexes consist of two symmetry-related T-shaped [(Tp(4Bo))(3)(CN)(9)Fe3M](-) subunits linked by two Na+ cations. Each polynuclear cluster in 1-6 strongly interacts with 12 adjacent such units through pi-pi interactions, leading to the formation of 3D 12-connected frameworks. Magnetic studies show appreciable magnetic anisotropies in compounds 1, 2, 4, and 5. Antiferromagnetic interactions were observed in complexes 3 and 6.