Crystal engineering from a 1D chain to a 3D coordination polymer accompanied by a dramatic change in magnetic properties.

A unique structural transformation in the crystalline state assisted by coordination substitution is induced during a dehydration process. A 1D chain coordination polymer is irreversibly converted to a 3D interpenetrated network accompanied by a change in magnetic properties from a paramagnetic material to a spin crossover system.

New iron(II) spin crossover coordination polymers [Fe(μ-atrz)3]X2·2H2O (X = ClO4¯, BF4¯) and [Fe(μ-atrz)(μ-pyz)(NCS)2]·4H2O with an interesting solvent effect.

A potential bridging triazole-based ligand, atrz (trans-4,4'-azo-1,2,4-triazole), is chosen to serve as building sticks and incorporated with a spin crossover metal center to form a metal organic framework. Coordination polymers of iron(II) with the formula [Fe(μ-atrz)(3)]X(2)·2H(2)O (where X = ClO(4)(-) (1·2H(2)O) and BF(4)(-) (2·2H(2)O)) in a 3D framework and [Fe(μ-atrz)(μ-pyz)(NCS)(2)]·4H(2)O (3·4H(2)O) in a 2D layer structure were synthesized and structurally characterized. The magnetic measurements of 1·2H(2)O and 2·2H(2)O reveal spin transitions near room temperature; that of 3 exhibits an abrupt spin transition at ~200 K with a wide thermal hysteresis, and the spin transition behavior of these polymers are apparently correlated with the water content of the sample.

Carbonyl Compounds and Toxicity Assessments of Emissions from a Diesel Engine Running on Biodiesels.

This study elucidates the effect of biodiesel on the emission of carbonyl compounds generated from a diesel engine (generator), and the related biotoxicity characteristics. The Microtox test and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay were conducted to evaluate the acute toxicity and cytotoxicity, respectively, of gaseous extracts from diesel engine exhaust. The engine was tested using diesel fuel and biodiesel blends (10, 30, 50, 75, and 100% of biodiesel by volume).

Biological toxicities of emissions from an unmodified engine fueled with diesel and biodiesel blend.

Conventional diesel and palm oil methyl esters were blended in 6 ratios (0, 10, 30, 50, 75 and 100% of biodiesel by volume) and fed into an unmodified 4-stroke engine with a constant output power. The semi-volatile and particulate products in the exhaust were collected separately and their biological toxicities evaluated by both Microtox test and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The Microtox test indicates that the TUVs (toxicity unit per liter exhaust sampled, TU/L-exhaust) in the semi-volatile extracts were 3 to 5 times those of the particulate extracts.

Catalytic wet air oxidation of phenol using CeO2 as the catalyst. Kinetic study and mechanism development.

Using a CeO2 catalyst prepared from CeCl3.7H2O under high thermal impact, the catalytic wet air oxidation (CWAO) of phenol was effectively implemented. With initial phenol concentrations of between (400 and 2500) mg/L, and at a temperature of 160 degrees C, the rate of phenol conversion increased with increased catalyst loading (0.