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Samarium hydrogen iodate Sm(IO3)3·HIO3 was successfully synthesized by the unconventional low-temperature solution-melt method, its structure was determined by X-ray diffraction analysis of single crystals. This compound crystallizes in the monoclinic space group P21/c with lattice parameters: a = 10.4637(6) Å, b = 7.4629(5) Å, c = 14.0174(13) Å, β = 110.53(0), Z = 6. In the studied structure, samarium atoms are surrounded by 8 oxygen atoms in a polyhedron in the form of a distorted square antiprism. The iodate groups are linked through common oxygen atoms of the SmO8 antiprism into a three-dimensional framework. The compound was characterized by X-ray diffraction, IR and NQR spectroscopy and EDX analysis. [ABSTRACT FROM AUTHOR]

Pyridinium cesium cobalt nitrate, (PyH)CsCo2(NO3)6, obtained from a nitric acid solution crystallizes in the orthorhombic space group Pnma with unit cell parameters a = 8.6905(14) Å, b = 11.9599(18) Å, c = 18.386(3) Å, V = 1911.0(5) Å3, and Z = 4. It consists of [Co(NO3)3]− layers, in which each Co2+ ion is connected with four monodentate bridging NO3-groups and one bidentate terminal NO3-group, forming a corrugated rectangular net. Magnetization and specific heat measurements show that (PyH)CsCo2(NO3)6 undergoes a long-range canted antiferromagnetic ordering in two steps at TC1 = 5.0 K and TC2 = 2.6 K. The temperature dependence of the magnetic susceptibility and the field dependence of the magnetization measured for (PyH)CsCo2(NO3)6 show that it is an Ising antiferromagnet. In support of these observations, our DFT + U + SOC calculations show that the Co2+ ions of (PyH)CsCo2(NO3)6 have an easy-axis magnetic anisotropy with preferred spin orientation along the b-axis. To a first approximation, the spin lattice of (PyH)CsCo2(NO3)6 is a weakly alternating Ising antiferromagnetic chain (J1/J2 ∼ 0.85), and these chains interact weakly (J3/J2 ∼ 0.07) to form a rectangular Ising antiferromagnetic lattice. In agreement with the prediction for a rectangular Ising antiferromagnet by Onsager, (PyH)CsCo2(NO3)6 undergoes a long-range antiferromagnetic ordering. [ABSTRACT FROM AUTHOR]

Pyridinium cesium cobalt nitrate, (PyH)CsCo2(NO3)6, obtained from a nitric acid solution crystallizes in the orthorhombic space group Pnma with unit cell parameters a = 8.6905(14) Å, b = 11.9599(18) Å, c = 18.386(3) Å, V = 1911.0(5) Å3, and Z = 4. It consists of [Co(NO3)3]− layers, in which each Co2+ ion is connected with four monodentate bridging NO3-groups and one bidentate terminal NO3-group, forming a corrugated rectangular net. Magnetization and specific heat measurements show that (PyH)CsCo2(NO3)6 undergoes a long-range canted antiferromagnetic ordering in two steps at TC1 = 5.0 K and TC2 = 2.6 K. The temperature dependence of the magnetic susceptibility and the field dependence of the magnetization measured for (PyH)CsCo2(NO3)6 show that it is an Ising antiferromagnet. In support of these observations, our DFT + U + SOC calculations show that the Co2+ ions of (PyH)CsCo2(NO3)6 have an easy-axis magnetic anisotropy with preferred spin orientation along the b-axis. To a first approximation, the spin lattice of (PyH)CsCo2(NO3)6 is a weakly alternating Ising antiferromagnetic chain (J1/J2 ∼ 0.85), and these chains interact weakly (J3/J2 ∼ 0.07) to form a rectangular Ising antiferromagnetic lattice. In agreement with the prediction for a rectangular Ising antiferromagnet by Onsager, (PyH)CsCo2(NO3)6 undergoes a long-range antiferromagnetic ordering. [ABSTRACT FROM AUTHOR]

We prepared a new compound, Co3(SeO3)(SeO4)(OH)2, having layers in a kagomé-like arrangement of Co2+ (spin S = 3/2) ions. This phase crystallizes in the orthorhombic space group Pnma (62) with unit cell parameters a = 11.225(9) Å, b = 6.466(7) Å and c = 11.530(20) Å. Its layers, parallel to the ab-plane, are made up of Co1O5 square pyramids and Co2O6 and Co3O6 octahedra. As the temperature is lowered, Co3(SeO3)(SeO4)(OH)2 undergoes three successive magnetic transitions at 27.5, 19.4 and 8.1 K, and the magnetization of Co3(SeO3)(SeO4)(OH)2 measured at 2.4 K exhibits a 1/3-magnetization plateau between 7.8 and 19.9 T. The H–T magnetic phase diagram constructed for Co3(SeO3)(SeO4)(OH)2 from ac and dc magnetic susceptibility, specific heat and magnetization measurements contains three magnetic phases I, II and III. Phase I is antiferromagnetic, while phases II and III are ferrimagnetic and responsible for the 1/3-magnetization plateau. To interpret these complex magnetic properties, we identified the correct spin lattice for Co3(SeO3)(SeO4)(OH)2 by evaluating its intralayer and interlayer spin exchanges based on spin-polarized DFT+U calculations. [ABSTRACT FROM AUTHOR]

A compound [Fe3O(H2O)3Prop6](NO3)·(HNO3) (1; Prop– is the C2H5COO– propionate) is prepared by the interaction of metallic iron and Fe(NO3)3 with concentrated propionic acid; the crystal structure of this compound is determined by single-crystal XRD at 100 K, 200 K, and 300 K. The experimental data show that the structure of 1 is a packing of complex cations [Fe3O(H2O)3Prop6]+ and nitrate anions with nitric acid molecules in packing voids. It is shown for the first time by polythermal XRD that 1 undergoes a structural phase transition manifested as partial ordering of aliphatic substituents in anionic ligands, changes in the configuration of NO2–OH⋯O–NO2 hydrogen bonds, and lowering of crystallographic symmetry of [Fe3O(H2O)3Prop6]+ complex cations. Thermal expansion of the crystal structure of 1 is studied in the temperature range 100-300 K; the experimental data show that the unit cell parameter b changes nonmonotonically upon heating and exhibits pronounced regions of positive and negative thermal expansion. [ABSTRACT FROM AUTHOR]

A compound [Fe3O(H2O)3Prop6](NO3)·(HNO3) (1; Prop– is the C2H5COO– propionate) is prepared by the interaction of metallic iron and Fe(NO3)3 with concentrated propionic acid; the crystal structure of this compound is determined by single-crystal XRD at 100 K, 200 K, and 300 K. The experimental data show that the structure of 1 is a packing of complex cations [Fe3O(H2O)3Prop6]+ and nitrate anions with nitric acid molecules in packing voids. It is shown for the first time by polythermal XRD that 1 undergoes a structural phase transition manifested as partial ordering of aliphatic substituents in anionic ligands, changes in the configuration of NO2–OH⋯O–NO2 hydrogen bonds, and lowering of crystallographic symmetry of [Fe3O(H2O)3Prop6]+ complex cations. Thermal expansion of the crystal structure of 1 is studied in the temperature range 100-300 K; the experimental data show that the unit cell parameter b changes nonmonotonically upon heating and exhibits pronounced regions of positive and negative thermal expansion. [ABSTRACT FROM AUTHOR]

The reaction of equimolar amounts of amidine 2,6-Me2C6H3NHC(But)NC6H3Me2-2,6 (1) and N,N-dimethyl-o-aminobenzyllithium o-Me2N-C6H4CH2Li afforded lithium amidinate [ButC(N-2,6-Me2C6H3)2]Li(THF)2(2). According to the X-ray diffraction data, the amidinate ligand in 2 is coordinated to the lithium atom in a κ1-N:η2-arene fashion. The reaction of 2 with NdCl3 in a molar ratio of 3:1 gave the tris(amidinate) complex [ButC(N-2,6-Me2C6H3)2]3Nd (3), in which the κ2-N,N-chelating amidinate ligand is coordinated to Nd3+via two nitrogen atoms. Complex 3 exhibited high catalytic activity in the ring-opening polymerization of ε-caprolactone and allowed the quantitative conversion of 100 equivalents of the monomer within 10 s. The synthesized polycaprolactone samples have high number-average molecular weights (Mn = 40.01 · 103) and low polydispersity indices (Mw/Mn = 1.41). In a mixture with 3–5 equivalents of PriOH, complex 3 also initiates the polymerization of ε-caprolactone, resulting in the quantitative conversion of 100 equivalents of the monomer with a high rate (within 60 s) under mild conditions. The molecular weights of the polymers are similar to the calculated values (Mn = (3.13–4.42) · 103), and the molecular weight distribution remains narrow (Mw/Mn = 1.61–1.75). [ABSTRACT FROM AUTHOR]

A mixed-valence compound Pb2Cu10O4(SeO3)4Cl7 has a complex structure consisting of one nonmagnetic Cu+ (S = 0) ion and four nonequivalent magnetic Cu2+ (S = 1/2) ions. It exhibits antiferromagnetic ordering at TN = 10.2 K. At a temperature below TN, a sequence of spin-flop transition at Bspin-flop = 1.3 T and 1/3 plateau formation at Bspin-flip = 4.4 K is observed in the magnetization curve M(B). The 1/3 magnetization plateau persists at least up to 53.5 T. The spin exchanges of Pb2Cu10O4(SeO3)4Cl7 evaluated by performing energy-mapping analysis based on DFT+U calculations show that the magnetic properties of Pb2Cu10O4(SeO3)4Cl7 are described by the (Cu2+)7 cluster of corner-sharing (Cu2+)4 tetrahedra, and that each (Cu2+)7 cluster has a S = 3/2 spin arrangement in the ground state. The 1/3 magnetization plateau observed for Pb2Cu10O4(SeO3)4Cl7 is explained by the field-induced flip of every second (Cu2+)7 cluster within a unit cell. [ABSTRACT FROM AUTHOR]