Complex Ions in Fused Salts

Abstract

April, 1958 COMPLEX IONS IN FUSED SALTS 417 value. At a temperature of 25' the values of k'and k" have been determined and the values of lcl are known with a precision of *2%; hence, by a trial and error procedure extreme values which E / and E" can have were found. From these calculations it has been possible t o show that E' = 15.8 f 0.5 kcal. The uncertainty in the value of E" is considerably larger; the value obtained was 16.0 f 2.5 kcal. From expressions of the transition state theoryjB values of the heat, free energy and entropy of activation were computed for the reaction between plutonyl ion and trivalent vana-(6) S. Glasstone, K. Laidler and H. Eyring, "The Theory of Rate Processes," MoGraw-Hill Book Co., Inc., New York, N. Y., 1941, p. 417. dium ion in terms of the principal species, i.e., P U O~+~ + V+3 + (activated complex) + H+. These quantities are AF* = 17.03 f 0.01 kcal./mole, AH* = 15.5 f 0.4 kcal./mole and AS* = -5* 2 cal./deg. The magnitudes of the rate constants k' and k" show the relative importance of the two paths which appear to be indicated in the reaction between plutonyl ion and vanadium(II1). Thus a t 25' about 90% of the over-all reaction occurs through the path in which a single hydrogen ion is liberated.Acknowledgment.-The author wishes to express his appreciation t o Drs.

Gel electrophoresis and diffusion of ring-shaped DNA

“…a gel). The model is based on the Rubinstein-Duke (RD) approach [7][8][9], and is extended here to include hernias, which are hair-pin shaped excursions out of the usual reptation tube. Hernias are crucial for polymers in the shape of a ring, in which the motion through the surrounding obstacles may be accomplished only by hernia fingering.…”

“…Each site i corresponds to a DNA segment, and has a state φ i , which can be either +, − or 0, as demonstrated in Fig 1. Note that in this description some information regarding the microscopic configuration is lost. However, it provides a convenient way to model the dynamics [7][8][9].…”

“…Most theoretical treatments [4][5][6][7][8][9][10] of the motion of the DNA through the gel are based on the reptation concept [11]. The DNA is pictured as moving through an impenetrable tube defined by the surrounding gel obstructions, with the motion mediated by a snake-like reptation of the polymer ends.…”

Deep Eutectic Solvents: Environmentally Friendly Media for Metal-Catalyzed Organic Reactions

“…The concept "Deep Eutectic Solvent" was firstly coined by Abbott et al (39) to describe the formation of a liquid eutectic mixture (melting point 12 ºC) starting from two solid materials with high melting points: i) choline chloride [ChCl, (2-hydroxyethyl)trimethylammoniun chloride, melting point 302 ºC] (40)(41)(42); and ii) urea (melting point 133 ºC) in a ratio 1:2 (1ChCl/2Urea) (39,43). However, it is important to note that strictly speaking Deep Eutectic Mixtures were used before to: i) lower the melting point of salts by forming metal-halide complexes (44,45); and ii) reduce the lattice energy of halide salts by the addition of urea (46). In the literature, all authors postulated the need of at least two components to synthesize the desired DES: i) a Hydrogen-Bond-Donor (HBD); and ii) a Hydrogen-Bond-Acceptor (HBA) (28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38).…”

Mischungen mit niedriger Übergangstemperatur (LTTMs) – eine neue Generation von Designer‐Lösungsmitteln

“…[13] [13,14] Allerdings war die Idee nicht neu; eutektische Mischungen waren bereits bekannt und wurden beispielsweise eingesetzt, um den Schmelzpunkt von Salzen durch Bildung von MetallHalogenid-Komplexen zu verringern. [15,16] Zusätzlich war beschrieben worden, dass Harnstoff mit einigen Halogenidsalzen [17] eine eutektische Mischung bildet, indem er die Gitterenergie und damit den Schmelzpunkt des Systems herabsetzt. Mehrere Theorien wurden zur Erklärung der Bildung stabiler Flüssigkeiten entwickelt.…”