Cloud Point Extraction and Spectrophotometric Determination of Uranium (VI) in Water Samples after Mixed Micelle-Mediated Extraction Using Chromotrope 2R as Complexing Agent

A rapid, selective and sensitive method for the preconcentration and determination of uranium (VI) by cloud point extraction (CPE) was developed. The method was based on the color reaction of 5.00 ng mL−1 uranium (VI) with 1.5×10−4 mol L−1 of chromotrope 2R in the presence of 0.015 mol L−1 potassi-um iodide at pH 8 in HEPES buffer and mixed micelle-mediated extraction of complex. The mixture of a nonionic surfactant (0.2 % (v/v) of (Triton X-114) and a cationic (2.0×10−4 mol L−1 of CTAB) was utilized as a suitable micellar medium for preconcentration and extraction of uranium (VI) complexes. Effect of extraction and reaction parameters was studied and optimum parameters were established. The analytical characteristics of the method (e.g. linear range, limit of detection, preconcentration and improvement factors) were obtained. Linearity was obeyed in the range of 0.2−10 ng mL−1 of uranium (VI) with a detection limit of 0.035 ng mL−1. The diverse ion effect of some anions and cations on the extraction efficiency of target ions was tested. The proposed method was successfully applied for the determination of uranium (VI) in various water samples. (doi: 10.5562/cca1922

Bis{N-[bis­(pyrrolidin-1-yl)phosphor­yl]-2,2,2-trichloro­acetamide}di­nitrato­dioxidouranium(VI)

The crystal structure of the title compound, [U(NO3)2O2(C10H17Cl3N3O2P)2], is composed of centrosymmetric [UO2(L)2(NO3)2] mol­ecules {L is N-[bis­(pyrrolidin-1-yl)phosphor­yl]-2,2,2-trichloro­acetamide, C10H17Cl3N3O2P}. The UVI ion, located on an inversion center, is eight-coordinated with axial oxido ligands and six equatorial oxygen atoms of the phosphoryl and nitrate groups in a slightly distorted hexa­gonal-bipyramidal geometry. One of the pyrrolidine fragments in the ligand is disordered over two conformation (occupancy ratio 0.58:0.42). Intra­molecular N—H⋯O hydrogen bonds between the amine and nitrate groups are found

catena-Poly[sodium-di-μ-aqua-sodium-bis[μ-2,2,2-trichloro-N-(dimorpholinophosphoryl)acetamide]]

The title compound, [Na2(C10H16Cl3N3O4P)2(H2O)2]n, can be considered as a two-dimensional coordination polymer in which one-dimensional chains are connected to each other by inter­molecular C—H⋯O hydrogen bonds involving the water mol­ecules. The NaI ion is five-coordinated in a distorted trigonal-bipyramidal geometry. The connection between the two NaI ions is facilitated by the two μ-O atoms of the carbonyl group of the 2,2,2-trichloro-N-(dimorpholino­phosphor­yl)acetamide (CAPh) ligand. A bridging coordination of the CAPh ligand via the carbonyl O atom is observed for the first time. The bridging water mol­ecules form inter­molecular O—H⋯O hydrogen bonds with the O atoms of the morpholine rings and the phosphoryl groups of neighboring CAPh mol­ecules

The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes

Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal–ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inversetrans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C¼M¼C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle

Antiarrhythmic and antioxidant activity of novel pyrrolidin-2-one derivatives with adrenolytic properties

A series of novel pyrrolidin-2-one derivatives (17 compounds) with adrenolytic properties was evaluated for antiarrhythmic, electrocardiographic and antioxidant activity. Some of them displayed antiarrhythmic activity in barium chloride-induced arrhythmia and in the rat coronary artery ligation-reperfusion model, and slightly decreased the heart rate, prolonged P–Q, Q–T intervals and QRS complex. Among them, compound EP-40 (1-[2-hydroxy-3-[4-[(2-hydroxyphenyl)piperazin-1-yl]propyl]pyrrolidin-2-one showed excellent antiarrhythmic activity. This compound had significantly antioxidant effect, too. The present results suggest that the antiarrhythmic effect of compound EP-40 is related to their adrenolytic and antioxidant properties. A biological activity prediction using the PASS software shows that compound EP-35 and EP-40 can be characterized by antiischemic activity; whereas, compound EP-68, EP-70, EP-71 could be good tachycardia agents

Cloud Point Extraction and Spectrophotometric Determination of Uranium (VI) in Water Samples after Mixed Micelle-Mediated Extraction Using Chromotrope 2R as Complexing Agent

A rapid, selective and sensitive method for the preconcentration and determination of uranium (VI) by cloud point extraction (CPE) was developed. The method was based on the color reaction of 5.00 ng mL−1 uranium (VI) with 1.5×10−4 mol L−1 of chromotrope 2R in the presence of 0.015 mol L−1 potassi-um iodide at pH 8 in HEPES buffer and mixed micelle-mediated extraction of complex. The mixture of a nonionic surfactant (0.2 % (v/v) of (Triton X-114) and a cationic (2.0×10−4 mol L−1 of CTAB) was utilized as a suitable micellar medium for preconcentration and extraction of uranium (VI) complexes. Effect of extraction and reaction parameters was studied and optimum parameters were established. The analytical characteristics of the method (e.g. linear range, limit of detection, preconcentration and improvement factors) were obtained. Linearity was obeyed in the range of 0.2−10 ng mL−1 of uranium (VI) with a detection limit of 0.035 ng mL−1. The diverse ion effect of some anions and cations on the extraction efficiency of target ions was tested. The proposed method was successfully applied for the determination of uranium (VI) in various water samples. (doi: 10.5562/cca1922