One-, Two-, and Three-Dimensional Heterospin Complexes Consisting of 4-(N-tert-Butyloxylamino)pyridine (4NOpy), Dicyanamide Ion (DCA), and 3d Metal Ions: Crystal Structures and Magnetic Properties of [M^II(4NOpy)_x(DCA)_y(CH₃CN)_z]_n (M = Mn, Co, Ni, Cu, Zn)

Solutions of 3d metal ion salts, M(NO₃)₂, 4-(N-tert-butyloxylamino)pyridine (4NOpy), and dicyanamide (DCA) in CH₃CN were mixed to afford single crystals of the polymeric complexes [M^II(4NOpy)_x(DCA)_y(CH₃CN)_z]_n (M^II = Mn (1), Co (2), Ni (3), Cu (4a and 4b), Zn (5)). X-ray crystallography revealed that the crystal structures are a three-dimensional (3-D) network for 1, 2-D networks for 2, 3, 4a, and 5, and a 1-D chain for 4b. Crystals of 2, 3, 4a, and 5 contained CH₃CN molecules as crystal solvents, which were readily desorbed in the ambient atmosphere. After desorption of the CH₃CN molecules, the crystal structures of 2 and 3 were confirmed to be slightly shrunk without destruction of the crystal lattice. Crystals of 2, 3, 4a, and 5 after desorption of crystal solvents were used for investigations of the magnetic properties. Complex 1 showed antiferromagnetic interactions to form a ferrimagnetic chain and exhibited the magnetic behavior of a 2-D (or 3-D) spin-canted antiferromagnet with T_N = 12 K. Complex 2 containing anisotropic Co^II ions also showed the behavior of a 1-D (or 2-D) spin-canted antiferromagnet with T_N = 6 K. In 3, 4a, and 4b, the aminoxyl of 4NOpy ferromagnetically interacted with the metal ion with coupling constants of J_M-NO/k_B = 45, 45, and 43 K, respectively. In 5, the magnetic couplings between the aminoxyls in 4NOpy through the diamagnetic Zn^II ion were weakly antiferromagntic (J_NO-NO = -1.2 K). DCA might be a weak antiferromagnetic connector for the metal chains.