Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Ionic room-temperature

The aluminium ion, charge -I- 3. ionic radius 0.045 nm, found in aluminium trifluoride, undergoes a similar reaction when a soluble aluminium salt is placed in water at room temperature. Initially the aluminium ion is surrounded by six water molecules and the complex ion has the predicted octahedral symmetry (see Table 2.5 ) ... [Pg.45]

ChloricfVII) acid fumes in moist air and is very soluble in water, dissolving with the evolution of much heat. Several hydrates are known the hydrate HCIO4. H2O is a solid at room temperature and has an ionic lattice [HjO ] [CIO4]. [Pg.341]

When an element has more than one oxidation state the lower halides tend to be ionic whilst the higher ones are covalent—the anhydrous chlorides of lead are a good example, for whilst leadfll) chloride, PbCl2, is a white non-volatile solid, soluble in water without hydrolysis, leadflV) chloride, PbC, is a liquid at room temperature (p. 200) and is immediately hydrolysed. This change of bonding with oxidation state follows from the rules given on p.49... [Pg.344]

When however the ionic addition of hydrogen bromide to 1 3 butadiene is car ried out at room temperature the ratio of isomeric allylic bromides observed is differ ent from that which is formed at — 80°C At room temperature the 1 4 addition product predominates... [Pg.406]

Calcium hydride is highly ionic and is insoluble in all common inert solvents. It can be handled in dry air at low temperatures without difficulty. When heated to about 500°C, it reacts with air to form both calcium oxide and nitride. Calcium hydride reacts vigorously with water in either Hquid or vapor states at room temperature. The reaction with water provides 1.06 Hters of hydrogen per gram CaH2. [Pg.298]

Few aHyl monomers have been polymerized to useful, weH-characterized products of high molecular weight by ionic methods, eg, by Lewis acid or base catalysts. Polymerization of the 1-alkenes by Ziegler catalysts is an exception. However, addition of acidic substances, at room temperature or upon heating, often gives viscous liquid low mol wt polymers, frequently along with by-products of uncertain stmcture. [Pg.80]

A second class of important electrolytes for rechargeable lithium batteries are soHd electrolytes. Of particular importance is the class known as soHd polymer electrolytes (SPEs). SPEs are polymers capable of forming complexes with lithium salts to yield ionic conductivity. The best known of the SPEs are the lithium salt complexes of poly(ethylene oxide) [25322-68-3] (PEO), —(CH2CH20) —, and poly(propylene oxide) [25322-69-4] (PPO) (11—13). Whereas a number of experimental battery systems have been constmcted using PEO and PPO electrolytes, these systems have not exhibited suitable conductivities at or near room temperature. Advances in the 1980s included a new class of SPE based on polyphosphazene complexes suggesting that room temperature SPE batteries may be achievable (14,15). [Pg.582]

The PTCR effect is complex and not fully understood in terms of the grain boundary states and stmcture. Both the PTCR effect and room temperature resistivities are also highly dependent on dopant type and ionic radius. Figure 11 (32) illustrates this dependence where comparison of the PTCR behavior and resistivity are made for near optimum concentrations of La ", Nd ", and ions separately substituted into BaTiO. As seen, lowest dopant concentration and room temperature resistivity are obtained for the larger radius cation (La " ), but thePTCR effect was sharpest for the smallest radius cation (Y " ), reflecting dual site occupancy of the Y " ion. [Pg.361]

Theoretical and applied aspects of microwave heating, as well as the advantages of its application are discussed for the individual analytical processes and also for the sample preparation procedures. Special attention is paid to the various preconcentration techniques, in part, sorption and extraction. Improvement of microwave-assisted solution preconcentration is shown on the example of separation of noble metals from matrix components by complexing sorbents. Advantages of microwave-assisted extraction and principles of choice of appropriate solvent are considered for the extraction of organic contaminants from solutions and solid samples by alcohols and room-temperature ionic liquids (RTILs). [Pg.245]

T. Welton, Room temperature ionic liquids. Solvents for synthesis and catalysis, Chem Rev 99 2071-2083 1999. C.M. Gordon, New developments in catalysis using ionic liquids, Appl. CatalA General 222 101-117 2001. [Pg.79]

Since both Si—O and Si—CHj bonds are thermally stable it is predictable that the polydimethylsiloxanes (dimethylsilicones) will have good thermal stability and this is found to be the case. On the other hand since the Si—O bond is partially ionic (51%) it is relatively easily broken by concentrated acids and alkalis at room temperature. [Pg.823]

The pyrites and marcasite structures can be thought of as containing 82 units though the variability of the interatomic distance and other properties suggest substantial deviation from a purely ionic description. Numerous higher polysulfides S have been characterized, particularly for the more electropositive elements Na, K, Ba, etc. They are yellow at room temperature, turn dark red on being heated, and may be thought of as salts of the polysulfanes... [Pg.681]

Room-temperature ionic liquids, salts with A,A-dialkylimidazolium cations in synthesis and catalysis 99CRV2071. [Pg.253]

There are many synonyms used for ionic liquids, which can complicate a literature search. Molten salts is the most common and most broadly applied term for ionic compounds in the liquid state. Unfortunately, the term ionic liquid was also used to mean molten salt long before there was much literature on low-melting salts. It may seem that the difference between ionic liquids and molten salts is just a matter of degree (literally) however the practical differences are sufficient to justify a separately identified niche for the salts that are liquid around room temperature. That is, in practice the ionic liquids may usually be handled like ordinary solvents. There are also some fundamental features of ionic liquids, such as strong... [Pg.1]

We had no good way to predict if they would be liquid, but we were lucky that many were. The class of cations that were the most attractive candidates was that of the dialkylimidazolium salts, and our particular favorite was l-ethyl-3-methylimid-azolium [EMIM]. [EMIMJCl mixed with AICI3 made ionic liquids with melting temperatures below room temperature over a wide range of compositions [8]. We determined chemical and physical properties once again, and demonstrated some new battery concepts based on this well behaved new electrolyte. We and others also tried some organic reactions, such as Eriedel-Crafts chemistry, and found the ionic liquids to be excellent both as solvents and as catalysts [9]. It appeared to act like acetonitrile, except that is was totally ionic and nonvolatile. [Pg.5]


See other pages where Ionic room-temperature is mentioned: [Pg.569]    [Pg.2408]    [Pg.569]    [Pg.2408]    [Pg.484]    [Pg.2579]    [Pg.2952]    [Pg.289]    [Pg.10]    [Pg.250]    [Pg.440]    [Pg.293]    [Pg.300]    [Pg.25]    [Pg.467]    [Pg.406]    [Pg.447]    [Pg.345]    [Pg.101]    [Pg.507]    [Pg.362]    [Pg.201]    [Pg.296]    [Pg.239]    [Pg.372]    [Pg.103]    [Pg.639]    [Pg.691]    [Pg.739]    [Pg.800]    [Pg.1185]    [Pg.1]    [Pg.2]    [Pg.4]    [Pg.5]    [Pg.7]   
See also in sourсe #XX -- [ Pg.327 ]




SEARCH



Aluminum deposition room-temperature ionic liquids

Cyclic voltammetry room-temperature ionic liquids

Electrocatalysis in Room Temperature Ionic Liquids

Electrochemical window room-temperature ionic liquids

Glassy carbon electrodes room-temperature ionic liquids

Ionic liquids room-temperature molten salts

Ionic room-temperature electrochemical

Lewis acids room-temperature ionic liquids

Molten Salts and Room-Temperature Ionic Liquids

Quaternary ammonium cations room-temperature ionic liquids

Reference Electrodes for Use in Room-temperature Ionic Liquids

Room temperature

Room temperature bulk ionic conductivity

Room temperature ionic liquid

Room temperature ionic liquid electrolyte

Room temperature ionic liquid reference

Room temperature ionic liquids (RTIL

Room temperature ionic liquids anions

Room temperature ionic liquids biocatalysis

Room temperature ionic liquids cations

Room temperature ionic liquids cohesive energy

Room temperature ionic liquids compressibility

Room temperature ionic liquids electrochemistry

Room temperature ionic liquids electrosynthesis

Room temperature ionic liquids extractions using

Room temperature ionic liquids industrial applications

Room temperature ionic liquids miscibility

Room temperature ionic liquids molecular structure

Room temperature ionic liquids organic synthesis

Room temperature ionic liquids parameters

Room temperature ionic liquids properties

Room temperature ionic liquids reaction

Room temperature ionic liquids surface tension

Room temperature ionic liquids synthesis

Room temperature ionic liquids thermal conductivity

Room temperature ionic liquids transport number

Room temperature ionic liquids vapor pressure

Room-temperature ionic liquid mixtures

Room-temperature ionic liquids (RTILs

Room-temperature ionic liquids amphiphiles

Room-temperature ionic liquids chloroaluminate systems

Room-temperature ionic liquids complexation study

Room-temperature ionic liquids complexes

Room-temperature ionic liquids data

Room-temperature ionic liquids definition

Room-temperature ionic liquids electrodeposition

Room-temperature ionic liquids electrolyte applications

Room-temperature ionic liquids imidazolium-type

Room-temperature ionic liquids micellization

Room-temperature ionic liquids nanoparticles

Room-temperature ionic liquids phase states

Room-temperature ionic liquids physicochemical properties

Room-temperature ionic liquids reference electrodes

Room-temperature ionic liquids self-assembly

Room-temperature ionic liquids solvatochromic probes

Room-temperature ionic liquids viscosity

Room-temperature ionic liquids volatility

Room-temperature ionic liquids, green

Self-assembly in room temperature ionic liquids

Solvent systems room-temperature ionic liquids, electronic

Temperature ionic

Voltammetry measurements, room-temperature ionic liquids

© 2024 chempedia.info