NOVEL NON-AQUEOUS ELECTROLYTES BASED ON COORDINATION BORON COMPOUNDS

The review provides a classification of electrolytes for modern chemical power sources, supercapacitors, sodium and lithium-ion batteries depending on changes in the physicochemical properties of salts and the products of their interaction with the solvent. A comparative analysis of physicochemical properties of salts depending on the structure of the cation and anion, and the influence of these properties on the properties of final solutions of electrolytes on the example of different classes of ionic liquids and chelatoborates of alkali metals and ammonium was conducted. The dependence of the physicochemical properties of electrolytes (solubility, electrical conductivity of solutions and the range of potentials of electrochemical stability) on the nature of the chelate ligand, electron donor and electroacceptor substituents in the bis (chelate) borate anion is analyzed. The electrical conductivity of salt solutions and ranges of potentials of electrochemical stability of the corresponding electrolytes containing other anions and used for a long time in chemical current sources are carried out. The advantages and disadvantages of using liquid electrolytes compared to solid and polymer electrolytes in terms of similarity of their structures have been detected. It is shown that the nature of the chelate ligand, electro-donor and electro-acceptor substituents in the bis (chelato) borate anion is an important factor in regulating the interaction with aprotic dipolar solvents. Mixed salts with two different chelate ligands typically combine the best characteristics of the corresponding monochelate compounds, but the methods for their preparation and purification are technologically significantly more complex compared to monochelate compounds. The analysis of the mechanism of formation of a protective film on a surface of electrode materials, dependence of potential on its formation and on the chemical nature of ligands is made. It is noted that bis (chelato) borate salts are more environmentally friendly compared to fluorine-containing complex salts. Emphasis is placed on the physicochemical properties of solutions of the most promising chelatoborate salts for use in lithium and sodium ion batteries, supercapacitors and electrolytic capacitors, and it is shown that bis (oxalate) borates and bis (salicylate gold) borates occupy ) borates in terms of electrical conductivity, solubility and potential range of electrochemical stability.

Crystal and molecular structures of dichloridopalladium(II) containing 2-methyl- or 2-phenyl-8-(diphenyphosphanyl)quinoline

The crystal structures of dichloridopalladium(II) complexes bearing 2-methyl- and 2-phenyl-8-(diphenylphosphanyl)quinoline, namely, dichlorido[8-(diphenylphosphanyl)-2-methylquinoline-κ2 N,P]palladium(II), [PdCl2(C22H18NP)] (1) and dichlorido[8-(diphenylphosphanyl)-2-phenylquinoline-κ2 N,P]palladium(II), [PdCl2(C27H20NP)] (2), were analyzed and compared to that of the 8-(diphenylphosphanyl)quinoline (PQH) analogue (3). In all three complexes, the phosphanylquinoline moiety acts as a bidentate P,N-donating chelate ligand. In the PQH complex (3), the PdII center has a typical planar coordination environment; however, both the methyl- and phenyl-substituted phosphanylquinoline (PQMe and PQPh, respectively) complexes (1) and (2) exhibit a considerable tetrahedral distortion around the PdII center, as parameterized by the τ4 values of 0.1555 (4) and 0.1438 (4) for (1) and (2), respectively. The steric interaction from the substituted group introduced at the 2-position of the quinoline ring enforces the cis-positioned Cl ligand to be displaced from the ideal coordination plane. Also, the ideally planar phosphanylquinoline five-membered chelate ring shows a large bending deformation by the displacement of the PdII center from the quinoline plane. In addition, in the phenyl-substituted complex (3), the coordinating quinolyl and the substituted phenyl rings are not co-planar to each other, having a dihedral angle of 33.08 (7)°. This twist conformation prohibits any intermolecular π–π stacking interaction between the quinoline planes, which is observed in the crystals of complexes (1) and (2).

4f-Metal Clusters Exhibiting Slow Relaxation of Magnetization: A {Dy7} Complex with An Hourglass-like Metal Topology

The reaction between Dy(NO3)3∙6H2O and the bulky Schiff base ligand, N-naphthalidene-2-amino-5-chlorobenzoic acid (nacbH2), in the presence of the organic base NEt3 has led to crystallization and structural, spectroscopic and magnetic characterization of a new heptanuclear [Dy7(OH)6(OMe)2(NO3)1.5(nacb)2(nacbH)6(MeOH)(H2O)2](NO3)1.5 (1) compound in ~40% yield. Complex 1 has a unique hourglass-like metal topology, among all previously reported {Dy7} clusters, comprising two distorted {Dy4(μ3-OH)3(μ3-OMe)}8+ cubanes that share a common metal vertex (Dy2). Peripheral ligation about the metal core is provided by the carboxylate groups of four η1:η1:η1:μ single-deprotonated nacbH− and two η1:η1:η2:η1:μ3 fully-deprotonated nacb2− ligands. Complex 1 is the first structurally characterized 4f-metal complex bearing the chelating/bridging ligand nacbH2 at any protonation level. Magnetic susceptibility studies revealed that 1 exhibits slow relaxation of magnetization at a zero external dc field, albeit with a small energy barrier of ~5 K for the magnetization reversal, most likely due to the very fast quantum-tunneling process. The combined results are a promising start to further explore the reactivity of nacbH2 upon all lanthanide ions and the systematic use of this chelate ligand as a route to new 4f-metal cluster compounds with beautiful structures and interesting magnetic dynamics.