The crystal structure and magnetic properties of 3-pyridinecarboxylate-bridged Re(II)M(II) complexes (M = Cu, Ni, Co and Mn)

Enantiomeric Complexes Based on Ruthenium(III) and 2,2'-Biimidazole: X-ray Structure and Magnetic Properties

We have prepared and characterized two Ru(III) compounds based on the 2,2'-biimidazole (H2biim) ligand, namely, a single complex of formula cis-[RuCl2(H2biim)2]Cl·4H2O (1) and a racemic mixture of formula {cis-[RuCl2(H2biim)2]Cl}2·4H2O (2), which contains 50% of Ru(III) complex 1. Both compounds crystallize in the monoclinic system with space groups C2 and P21 for 1 and 2, respectively. These complexes exhibit the metal ion bonded to four nitrogen atoms from two H2biim molecules and two chloride ions, which balance part of the positive charges in a distorted octahedral geometry. Significant differences are observed in their crystal packing, which leads to the observation of differences in their respective magnetic behaviors. Despite having imidazole rings in both compounds, π-π stacking interactions occur only in the crystal structure of 2, and the shortest intermolecular Ru···Ru separation in 2 is consequently shorter than that in 1. Variable-temperature dc magnetic susceptibility measurements performed on polycrystalline samples of 1 and 2 reveal different magnetic behaviors at low temperatures: while 1 behaves pretty much as a magnetically isolated mononuclear Ru(III) complex with S = 1/2, 2 exhibits the behavior of an antiferromagnetically coupled system with S = 0 and a maximum in the magnetic susceptibility curve at approximately 3.0 K.

Crystal structure and magnetic study of the complex salt [RuCp(PTA)2-μ-CN-1κC:2κN-RuCp(PTA)2][Re(NO)Br4(EtOH)0.5(MeOH)0.5]

A new RuII-ReII complex salt, μ-cyanido-κ2 C:N-bis-[(η5-cyclo-penta-dien-yl)bis(3,5,7-tri-aza-phosphaadamantane-κP)ruthenium(II)] tetra-bromido-(ethanol/methanol-κO)nitrosylrhenate(II), [Ru(CN)(C5H5)2(C6H12N3P)4][ReBr4(NO)(CH4O)0.5(C2H6O)0.5] or [RuCp(PTA)2-μ-CN-1κC:2κ2 N-RuCp(PTA)2][Re(NO)Br4(EtOH)0.5(MeOH)0.5] (PTA = 3,5,7-tri-aza-phosphaadaman-tane) was obtained and characterized by single-crystal X-ray diffraction, elemental analysis and infrared spectroscopy. The title salt was obtained by liquid-liquid diffusion of methanol/DMSO solutions of (NBu4)[Re(NO)Br4(EtOH)] and [(PTA)2CpRu-μ-CN-1κC:2κ2 N-RuCp(PTA)2](CF3SO3). The RuII and ReII independent moieties correspond to a binuclear and mononuclear complex ion, respectively. A deep geometrical parameter analysis was performed, and no significant differences were found with earlier reports containing similar mol-ecules. The magnetic properties were investigated in the temperature range 2.0-300 K, and the complex behaves as a quasi-magnetically isolated spin doublet with weak anti-ferromagnetic inter-actions.

Two Co(II) coordination polymers: magnetic properties and application values against chronic subdural hematoma

In this current experiment, by applying the mixed-ligand synthesis method, two coordination polymers (CPs) containing Co(II) were created triumphantly with reaction between 1,3-bis(1-imidazoly)benzene (mbib) and Co(II) salts with the aid of diverse carboxylic ligands, and their chemical formulae are [Co₃(opda)₃(mbib)₄(H₂O)₄]·2H₂O (1, H₂opda is 1,2-phenylenediacetic acid) and [Co(mpda)(mbib)]·H₂O (2, H₂mpda is 1,3-phenylenediacetic acid). The two compounds' magnetic performances suggest that between the adjacent metal ions, there present the antiferromagnetic coupling. The evaluation of their treatment activity against chronic subdural hematoma was carried out and the relevant mechanism was studied simultaneously. Firstly, before the treatment of compound, the chronic subdural hematoma was generated. Furthermore, the enzyme-linked immunosorbent assay detection kit was implemented and in hematoma capsule, the anti-inflammatory cytokines level and pro-inflammatory cytokines level was detected. Additionally, the cytotoxicity of compounds 1 and 2 on the normal human cells was determined with Cell Counting Kit-8 assay. Above all, we proved compound 1 decreased the pro-inflammatory cytokines content and increased the anti-inflammatory cytokines content in the hematoma capsule, which is much stronger than that of compound 2. Both compounds 1 and 2 showed no cytotoxicity on the normal human cells.

H2 and carbon-heteroatom bond activation mediated by polarized heterobimetallic complexes

The field of heterobimetallic chemistry has rapidly expanded over the last decade. In addition to their interesting structural features, heterobimetallic structures have been found to facilitate a range of stoichiometric bond activations and catalytic processes. The accompanying review summarizes advances in this area since January of 2010. The review encompasses well-characterized heterobimetallic complexes, with a particular focus on mechanistic details surrounding their reactivity applications.

Two new MOFs based on 5-((4-carboxypyridin-2-yl)oxy) isophthalic acid displaying unique selective CO2 gas adsorption and magnetic properties

The reaction of Cu(ii)/Co(ii) with a N-heterocyclic carboxylate ligand produced two new MOFs with different topologies. The Cu-MOF showed selective adsorption for CO₂ over CH₄, and the antiferromagnetic properties existed in the two MOFs.