I. I. Eliseev

Dependence of Extraction Properties of 2,6-Dicarboxypyridine Diamides on Extractant Structure

Abstract New diamides of dipicolinic acid have been prepared and their affinity for lanthanides, americium, and uranium has been explored using the liquid-liquid extraction method. These extractants feature mixed alkyl/aryl substituents. The highest extraction is seen for phenyl/ethyl derivatives. The structure-reactivity relationship for extraction and solubility is discussed.

New polymeric chemical sensors for determination of lead ions

New polymeric electrochemical sensors for determining the content of lead were suggested. As the active substance of the polymeric membranes of the sensors was used N,N′-tetrabutyldipicolinamide, the compound exhibiting a high extractive capacity for heavy metal ions. The selectivity of the sensors with respect to lead ions in the presence of copper, cadmium, and zinc in a considerable excess was studied.

Synthesis of new vasotocin analogues: effects on renal water and ion excretion in rats.

Vasopressin and nonmammalian hormone vasotocin are known to increase the water permeability of mammalian collecting ducts, frog skin and the urinary bladder. Neurohypophysial nonapeptides have also been shown to interfere with the regulation of renal ion transport. The subject of this study was a search for vasopressin and vasotocin analogues with selective effects on renal water, sodium and potassium excretion. During this study, we synthesised the following peptides: 13 vasotocin analogues modified at positions 4 (Thr or Arg), 7 (Gly or Leu) and 8 (d‐Arg, Lys or Glu); 4 vasopressin analogues modified at positions 4 and 8; and 9 peptides shortened or extended at the C‐terminal or with substitutions for Gly‐NH2. Most of these peptides had mercaptopropionic acid (Mpa) instead of Cys in position 1. The effects of these nonapeptides on renal water, sodium and potassium transport were evaluated in in vivo experiments using Wistar rats. Some nonapeptides possessed antidiuretic, natriuretic and kaliuretic activities ([Mpa1]‐arginine vasotocin, [Mpa1, homoArg8]‐vasotocin, [Mpa1, Thr4]‐arginine vasotocin and [Mpa1, Arg4]‐arginine vasopressin). Substitutions at positions 4 and 8 increased the selectivity of peptide actions. The antidiuretic [d‐Arg8]‐vasotocin analogues had no effects on sodium excretion. [Mpa1, Arg4]‐arginine vasotocin was antidiuretic and kaliuretic but not natriuretic. [Mpa1, Glu8]‐oxytocin had weak natriuretic activity without any effects on water and potassium transport. In accordance with the data obtained, synthesised vasotocin analogues could be good candidates for pharmaceuticals selectively regulating renal sodium and potassium transport, which is of clinical importance. Copyright

New polar fluorinated diluents for diamide extractants

The extraction properties of TODGA solutions in novel polar fluorinated diluents were investigated. The extraction of nitric acid, Am and lanthanides was studied. It was found that aromatic fluorinated diluents provide the highest loading capacity of organic phase comparing with aliphatic diluents. A new solvent on the base of TODGA in meta-nitrobenzotrifluoride is the most promising for technological purposes.

cis-Dichlorido(dimethyl sulfoxide-κS)(N,N,N′,N′-tetra­methyl­guanidine-κN′′)platinum(II)

In the title compound, cis-[PtCl2(C5H13N3)(C2H6OS)], the four-coordinate PtII atom is bonded to one N atom of the N,N,N′,N′-tetramethylguanidine ligand, one dimethyl sulfoxide S atom and two chloride ligands, forming a cis-square-planar geometry. The bond lengths and angles of the N—Pt—Cl functionality are typical for imine dichloridoplatinum(II) complexes. The H atom of the imino group is oriented towards the O atom of the sulfoxide group of a neighboring molecule and forms an N—H⋯O hydrogen bond.

Red photo- and electroluminescent half-lantern cyclometalated dinuclear platinum(II) complex

Abstract New cyclometalated dinuclear platinum(II) complex bearing bridged 4,6-dimethylpyrimidine-2(1H)-thiolate (μ-C6H7N2S-κN,S) ligands, [{Pt(ppy)(μ-C6H7N2S-κN,S)}2] (3) (ppy=(2-phenylpyridinato-C2,N)) was prepared via the reaction of chloro-bridged dimer [{Pt(ppy)Cl}2] with 4,6-dimethylpyrimidine-2(1H)-thione (C6H8N2S) in the presence of t-BuOK. The complex holds dinuclear frameworks with short Pt(II)···Pt(II) distance (2.8877(3) Å), and exhibit red intense luminescence from the triplet metal-metal-to-ligand charge-transfer at 697 nm in CH2Cl2 solution and at 649 nm in solid state at RT. Single crystal XRD analysis reveals the metallophilic interactions Pt···Pt with significant covalent contribution in the structure of 3 which were studied by quasi-relativistic and relativistic DFT calculations (viz., M06/MWB60(Pt) and 6-311+G* (other atoms); M06/DZP-DKH levels of theory) and topological analysis of the electron density distribution within the framework of Bader’s theory (QTAIM method). Estimated strength of the Pt···Pt contact is 8.1–12.2 kcal/mol and it is mostly determined by crystal packing effects and weak attractive interactions between the adjacent metal centers due to overlapping of their dz2 and pz orbitals. An organic light-emitting diode based on this complex showed red electroluminescence with maximal luminance of 115 cd/m2 and current efficiency of 2.45 cd/A at this luminance.