Bis{2-[bis-(3,5-dimethyl-1H-pyrazol-1-yl-κN(2))meth-yl]pyridine-κN}cobalt(II) dinitrate.

The central Co(II) ion in the title complex, [Co(C(16)H(19)N(5))(2)](NO(3))(2), is located on a twofold rotation axis and has a slightly distorted octa-hedral coordination sphere. It is bonded to six N atoms from two 2-[bis-(3,5-dimethyl-1H-pyrazol-1-yl)meth-yl]pyridine ligands. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions.

Bis{2-[bis-(3,5-dimethyl-1H-pyrazol-1-yl-κN)meth-yl]pyridine-κN}copper(II) dinitrate.

In the mononuclear title complex, [Cu(C(16)H(19)N(5))(2)](NO(3))(2), the Cu(II) ion is located on a twofold rotation axis and is six-coordinated by six N atoms from two 2-[bis-(3,5-dimethyl-1H-pyrazol-1-yl)meth-yl]pyridine ligands, forming a distorted octa-hedral geometry. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions.

Syntheses, crystal structures and magnetic properties of a novel family of penta-manganese complexes derived from an assembly system containing polydentate hydroxy-rich Schiff-base ligands.

The syntheses, crystal structures, and magnetochemical characterization are reported of a novel family of four pentanuclear manganese complexes, namely, [Mn(III)(5)(mu(3)-O)(2)(L(1))(4)(O(2)CMe)(3)(CH(3)OH)].1.5CH(3)OH.2.5H(2)O (1), [Mn(III)(5)(mu(3)-O)(2)(L(1))(4)(O(2)CPh)(3)(CH(3)OH)].2CH(3)OH.2.25CH(3)CN.1.5H(2)O (), [Mn(II)Mn(III)(4)(HL(2))(2)(L(2))(2)(O(2)C Me)(4))].CH(3)OH.H(2)O (3) and [Mn(II)Mn(III)(4)(HL(2))(2)(L(2))(2)(O(2)CPh)(4))].1.5H(2)O (4), where H(2)L(1) is 3,5-dibromosalicylidene-2-ethanolamine and H(3)L(2) is 3-(2-hydroxy-3,5-dibromobenzylideneamino)propane-1,2-diol. All the complexes can be obtained from a reaction system containing the trinuclear species [Mn(3)O(O(2)CR)(6)(Py)(3)](0/+) (R = Me or Ph) and H(2)L(1) or H(3)L(2) with similar procedures. Both cores in complexes 1 and 2 feature two mu(3)-O(2-) atoms, four L(1)(2-) ligands together with three RCO(2)(-) groups (R = Me or Ph) bridging five Mn(III) atoms to form an incomplete cubane extended at one face by an incomplete adamantane unit, which is an unprecedented structural type in Mn chemistry. Complexes 3 and 4 both have a rare [Mn(II)Mn(III)(4)(mu(2)-O(alkoxide))(6)](8+) core, which can be regarded as two {Mn(II)Mn(III)(2)(mu(2)-O(alkoxide))(3)} scalene triangles, sharing the Mn(II) vertex. The dc magnetic susceptibility studies in the 2-300 K range for complexes 1-4 reveal the presence of overall antiferromagnetic intracluster interactions. A simple 3-J model was found to be adequate to describe the variable-temperature dc susceptibility data of complexes 1-4. The results have allowed us to compare the obtained magnetic exchange with magneto-structural correlations found previously for manganese-oxo clusters.

Genotoxicity of organic bentonite particles in vitro / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the genotoxicity induced by organic bentonite particles in vitro.</p><p><b>METHODS</b>Human B lymphoblast cells (HMy2.CIR) were exposed to organic bentonite particles at the doses of 0, 1.88, 3.75, 7.50 and 15.00 µg/ml for 24, 48 and 72 h, calcium sulfate (30 µg/ml) and SiO2 (30 and 240 µg/ml) served as negative and positive controls, respectively. The genotoxicity of organic bentonite particles and soluble fraction was detected using comet assay and Cytokinesis-block micronucleus (CBMN) assay.</p><p><b>RESULTS</b>The results of comet assay indicated that % tail DNA increased with the exposure doses and time in organic bentonite group, % tail DNA at the dose of 15.00 µg/ml for 24 h, 48 h and 72 h in organic bentonite group were 3.20 ± 0.19, 4.63 ± 0.88 and 9.49 ± 1.31 respectively which were significantly higher than those in calcium sulfate group (1.40 ± 0.11, 1.37 ± 0.22 and 0.90 ± 0.16) and those in 30 µg/ml SiO2 group (1.83 ± 0.21, 1.41 ± 0.27 and 2.48 ± 0.25) (P < 0.01). The results of CBMN assay showed that micronucleus frequencies (MNF) in organic bentonite group (except for 1.88 µg/ml for 24 h) were significantly higher than those in 30 µg/ml calcium sulfate group (MNF for 24, 48 and 72 h were 1.33‰ ± 0.58‰, 1.33‰ ± 1.15‰ and 1.33‰ ± 0.58‰) and those in 30 µg/ml SiO2 group (2.00‰ ± 0.00‰, 1.68‰ ± 0.58‰ and 2.33‰ ± 0.58‰) (P < 0.01). The results of two assays demonstrated that the soluble fraction of organic bentonite did not induce the genotoxicity.</p><p><b>CONCLUSION</b>The organic bentonite dusts can induce the genotoxicity in vitro, which may be from the particle fraction.</p>

Comparative study of cytotoxicity induced by two kinds of bentonite particles in vitro / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study comparatively the cytotoxicity induced by acid bentonite and organic bentonite.</p><p><b>METHODS</b>The cytotoxicity of two kinds of bentonite was detected using CCK8 assay, neutral red uptake (NRU) assay, lactate dehydrogenase (LDH) leakage assay, apoptosis assay and hemolysis assay. In hemolysis assay human erythrocytes served as target cells and were exposed to the two kinds of bentonite at the doses of 0, 0.3125, 0.6250, 1.2500 and 2.5000 mg/ml for ten min. In other four assays, human B lymphoblast cells (HMy2.CIR) served as target cells and were exposed to the two kinds of bentonite at the doses of 0, 10, 20, 30, 60, 120 and 180 microg/ml for four h.</p><p><b>RESULTS</b>In hemolysis assay, the hemolysis rates induced by two kinds of bentonite at all doses were significantly higher than that of control (P<0.05); in CCK-8 assay, the cellular activities in acid bentonite group at the doses > or =30 microg/ml and in organic bentonite group at the doses > or =20 microg/ml were significantly lower than that of control (P<0.01); the similar results appeared in NRU assay and LDH assay, and the dose-effect relationship was observed in above 4 assays. In apoptosis assay, the early apoptosis cell rates in acid bentonite group at the dose of 180 microg/ml and in organic bentonite group at the doses of 120,180 microg/ml were significantly higher than that of control (P<0.05). Moreover, the results of five in vitro assays indicated the cytotoxicity induced by organic bentonite was higher than that induced by acid bentonite.</p><p><b>CONCLUSION</b>Two kinds of bentonite could induce cytotoxicity, such as apoptosis and damage of cell membrane. The cytotoxicity of organic bentonite is higher than that of acid bentonite due to the different industrial treatment and characteristics of two kinds of bentonite particles.</p>