Tris(ethyl-enedi-amine)-cobalt(II) dichloride.

The title compound, [Co(II)(C2H8N2)3]Cl2, was obtained unexpectedly as the product of an attempted solvothermal synthesis of cobalt selenide from the elements in the presence of NH4Cl in ethyl-enedi-amine solvent. The three chelate rings of the distorted octa-hedral [Co(C2H8N2)3](2+) complex cation adopt twisted conformations about their C-C bonds. The spread of cis-N-Co-N bond angles [80.17 (6)-98.10 (6)°] in the title compound is considerably greater than the equivalent data for [Co(III)(C2H8N2)3]Cl3 [Takamizawa et al. (2008 ▶). Angew. Chem. Int. Ed. 47, 1689-1692]. In the crystal, the components are linked by numerous N-H⋯Cl hydrogen bonds, generating a three-dimensional network in which the cationic complexes are stacked in columns along [010] and separated by columns of chloride anions

CaCu2(SeO3)2Cl2: spin-1/2 Heisenberg chain compound with complex frustrated interchain couplings

We report the crystal structure, magnetization measurements, and band-structure calculations for the spin-1/2 quantum magnet CaCu2(SeO3)2Cl2. The magnetic behavior of this compound is well reproduced by a uniform spin-1/2 chain model with the nearest-neighbor exchange of about 133 K. Due to the peculiar crystal structure, spin chains run in the direction almost perpendicular to the structural chains. We find an exotic regime of frustrated interchain couplings owing to two inequivalent exchanges of 10 K each. Peculiar superexchange paths grant an opportunity to investigate bond-randomness effects under partial Cl-Br substitution.Comment: Extended version: 9 pages, 7 figures, 4 table

Cs7Sm11[TeO3]12Cl16 and Rb7Nd11[TeO3]12Br16, the new tellurite halides of the tetragonal Rb6LiNd11[SeO3]12Cl16 structure type

The authors thank the Russian Foundation for Basic Researches for the support of this work under Grants No. 14-03-00604_a and 12-03-92604-KO_a. The X-ray study of compound II was made possible due to M.V. Lomonosov Moscow State University Programm of Development. PL thanks the University of St Andrews and EPSRC for DTA Studentships to CB and LJD.Two new rare-earth – alkali – tellurium oxide halides were synthesized by a salt flux technique and characterized by single-crystal X-ray diffraction. The structures of the new compounds Cs7Sm11[TeO3]12Cl16 (I) and Rb7Nd11[TeO3]12Br16 (II) (both tetragonal, space group I4/mcm) correspond to the sequence of [MLn11(TeO3)12] and [M6×16] layers and bear very strong similarities to those of known selenite analogs. We discuss the trends in similarities and differences in compositions and structural details between the Se and Te compounds; more members of the family are predicted.PostprintPeer reviewe

Tris(ethylenediamine)cobalt(II) dichloride

The title compound, [CoII(C2H8N2)3]Cl2, was obtained unexpectedly as the product of an attempted solvothermal synthesis of cobalt selenide from the elements in the presence of NH4Cl in ethylenediamine solvent. The three chelate rings of the distorted octahedral [Co(C2H8N2)3]2+ complex cation adopt twisted conformations about their C—C bonds. The spread of cis-N—Co—N bond angles [80.17 (6)–98.10 (6)°] in the title compound is considerably greater than the equivalent data for [CoIII(C2H8N2)3]Cl3 [Takamizawa et al. (2008). Angew. Chem. Int. Ed. 47, 1689–1692]. In the crystal, the components are linked by numerous N—H...Cl hydrogen bonds, generating a three-dimensional network in which the cationic complexes are stacked in columns along [010] and separated by columns of chloride anions

Tris(ethylenediamine)cobalt(II) dichloride

The title compound, [Co(II)(C(2)H(8)N(2))(3)]Cl(2), was obtained unexpectedly as the product of an attempted solvothermal synthesis of cobalt selenide from the elements in the presence of NH(4)Cl in ethyl­enedi­amine solvent. The three chelate rings of the distorted octa­hedral [Co(C(2)H(8)N(2))(3)](2+) complex cation adopt twisted conformations about their C—C bonds. The spread of cis-N—Co—N bond angles [80.17 (6)–98.10 (6)°] in the title compound is considerably greater than the equivalent data for [Co(III)(C(2)H(8)N(2))(3)]Cl(3) [Takamizawa et al. (2008 ▶). Angew. Chem. Int. Ed. 47, 1689–1692]. In the crystal, the components are linked by numerous N—H⋯Cl hydrogen bonds, generating a three-dimensional network in which the cationic complexes are stacked in columns along [010] and separated by columns of chloride anions