New Iron Oxide Nanoparticles Catechol-Grafted with Bis(amidoxime)s for Uranium(VI) Depletion of Aqueous Solution.

Environmental pollution caused by heavy metals constitutes a serious public health problem. In the case of uranium depletion, amidoxime groups are important because of their high affinity for uranium(VI). New series of bis(amidoxime)s with catechol-derived anchor groups were tested (b-AMD-1 and b-AMD-2).

Synthesis and antioxidant properties of pulvinic acids analogues.

The synthesis of three types of pulvinic acid analogues, using a diversity-oriented strategy starting from a single compound, dimethyl l-tartrate, is described. Lacey-Dieckmann condensation, alcohol dehydration and Suzuki-Miyaura cross-couplings were employed in the course of the analogues syntheses. The evaluation of the antioxidant properties of the 28 synthesized analogues was carried out using antioxidant capacity assays (protection of thymidine and β-carotene) and free radical scavenging assays (DPPH radical and ABTS radical cation).

Norbadione a: kinetics and thermodynamics of cesium uptake in aqueous and alcoholic media.

Norbadione A (NbA) is a mushroom pigment, which is assumed to be involved in (137)Cs accumulation all over Europe during the Chernobyl nuclear accident. NbA bears seven acid-base functional groups, among which are two enolic and two carboxylic acid moieties. This work deals with complex formation of Cs(+) and NbA in ethanol, ethanol/water (9:1) (M1), and water with, when required, the support of two Cs(+) ionophore probes, calix[4]arene-bis(crown-6-ether)dioxycoumarine (A1) and its tetrasuslfonated form (A2).

Kinetics, thermodynamics, and modeling of complex formation between calix[4]biscrowns and cesium.

Complex formations between calix[4]arene-bis(crown-6-ether) calix-COU2 (A1) and the tetrasulfonated species calix-COUSULF (A2) with Cs(+) are investigated in water and ethanol, and in 9:1 (M1) and 1:9 (M2) H(2)O/EtOH v:v mixtures, by chemical relaxation and molecular modeling. In ethanol and M2, two Cs(+) are included in A1 in two kinetic steps, whereas complex formation in M1 becomes controlled by a slow first-order kinetic process, which is accompanied by very fast Cs(+) inclusions, second-order rate constant: k'(1) = (3.4 +/- 0.

Synthesis, antioxidant properties and radioprotective effects of new benzothiazoles and thiadiazoles.

In this work, we report the synthesis and characterization of new compounds derived from benzothiazoles and thiadiazoles. We observed that structural modifications on these skeletons affected the antioxidant activity. Thiol and aminothiol compounds derived from thiadiazoles and benzothiazoles showed an interesting antioxidant property.

Total synthesis of norbadione A.

A short, convergent synthesis of the mushroom pigment norbadione A is described. The construction of an appropriately substituted naphtholactone intermediate involved a regioselective Diels-Alder reaction between a bis(triisopropylsilyloxy)diene and 2,6-dichlorobenzo-1,4-quinone. A double Suzuki-Miyaura cross-coupling between a diboronate and two identical enol triflates was another key feature of the synthesis.

Uncatalyzed reaction of silyl ketene acetals with oxalyl chloride: a straightforward preparation of symmetrical pulvinic acids.

[reaction: see text] Several natural pulvinic acids were synthesized. Silyl ketene acetals derived from methyl arylacetates (4 equiv) reacted with oxalyl chloride at -78 degrees C, without the need of adding a catalyst. After treatment of the crude diketones with DBU and acidification with hydrochloric acid, symmetrical pulvinic acids methyl esters were obtained.

Photocatalytic degradation of 2-phenethyl-2-chloroethyl sulfide in liquid and gas phases.

This work explores the ability of photocatalysis to decontaminate water and air from chemical warfare agent mustard using its simulant 2-phenethyl 2-chloroethyl sulfide (PECES). PECES like mustard slowly dissolves in water with hydrolysis, forming 2-phenethyl 2-hydroxyethyl sulfide (PEHES). Irradiation of TiO2 suspension containing PECES with the unfiltered light of a mercury lamp (lambda > or = 254 nm) decomposed all PECES mostly via photolysis.