Diaqua­(1,10-phenanthrolin-2-ol)nickel(II) dinitrate

In the mononuclear title complex, [Ni(C12H8N2O)2(H2O)2](NO3)2, the NiII ion is coordinated in a distorted octa­hedral geometry. The dihedral angle between the two mean planes defined by the phenanthroline ligands is 88.26 (6)°. Intra- and intermolecular O—H⋯O hydrogen bonds between the cation and the anions lead to the formation of a layered arrangement parallel to (010)

Phase diagram and exotic spin-spin correlations of anisotropic Ising model on the Sierpi\'nski gasket

The anisotropic antiferromagnetic Ising model on the fractal Sierpi\'{n}ski gasket is intensively studied, and a number of exotic properties are disclosed. The ground state phase diagram in the plane of magnetic field-interaction of the system is obtained. The thermodynamic properties of the three plateau phases are probed by exploring the temperature-dependence of magnetization, specific heat, susceptibility and spin-spin correlations. No phase transitions are observed in this model. In the absence of a magnetic field, the unusual temperature dependence of the spin correlation length is obtained with $0 \leq$J$_b/$J$_a<1$, and an interesting crossover behavior between different phases at J$_b/$J$_a=1$ is unveiled, whose dynamics can be described by the J$_b/$J$_a$-dependence of the specific heat, susceptibility and spin correlation functions. The exotic spin-spin correlation patterns that share the same special rotational symmetry as that of the Sierpi\'{n}ski gasket are obtained in both the $1/3$ plateau disordered phase and the $5/9$ plateau partially ordered ferrimagnetic phase. Moreover, a quantum scheme is formulated to study the thermodynamics of the fractal Sierpi\'{n}ski gasket with Heisenberg interactions. We find that the unusual temperature dependence of the correlation length remains intact in a small quantum fluctuation.Comment: 9 pages, 12 figure

Bis(2-chloro-1,10-phenanthroline-κ2 N,N′)(thio­cyanato-κN)zinc (2-chloro-1,10-phenanthroline-κ2 N,N′)tris­(thio­cyanato-κN)zincate

The asymmetric unit of the title compound, [Zn(NCS)(C12H7ClN2)2][Zn(NCS)3(C12H7ClN2)], contains two cations and two anions. In the cations, the ZnII ions have distorted trigonal–bipyramidal environments formed by four N atoms from two 2-chloro-1,10-phenanthroline (cphen) ligands and one N atom from a thio­cyanate ligand. The ZnII atoms in the complex anions also have distorted trigonal–bipyramidal environments, formed by two N atoms from a cphen ligand and three N atoms from three thio­cyanato ligands. The crystal packing exhibits π–π inter­actions between the rings of the cphen ligands [shortest centroid–centroid distance = 3.586 (5) Å] and short inter­molecular S⋯Cl [3.395 (5) Å] and S⋯S [3.440 (4) Å] contacts