Alkali metals ammonia

Chromic(VI) acid Acetic acid, acetic anhydride, acetone, alcohols, alkali metals, ammonia, dimethylformamide, camphor, glycerol, hydrogen sulflde, phosphorus, pyridine, selenium, sulfur, turpentine, flammable liquids in general... 

Hydrazine Alkali metals, ammonia, chlorine, chromates and dichromates, copper salts, fluorine, hydrogen peroxide, metallic oxides, nickel, nitric acid, liquid oxygen, zinc diethyl... 

The chemical resistance of PTFE is almost universal It resists attack by aqua regia, hot fummg nitnc acid, hot caustic, chlorine, chlorosulfonic acid, and all solvents. Despite this broad chemical resistance, PTFE is attacked by molten alkali metals, ammonia solutions of such metals, chlorine trifluoride, and gaseous fluonne at elevated temperature and pressure PTFE swells or dissolves m certam highly fluonnated oils near its melting point. Specific lists of chemicals compatible with PTFE are available [/.8]... 

Scheme 159) [549, 550]. Temperature and electrolyte concentration are found to have a profound effect on the reaction rate. The Bu4N(Hg) can be used for the reduction of -estradiol 3-methyl ether and the reaction has been shown to be more selective than the conversion methods based on alkali metal-ammonia reduction [551]. 

PTFE is insoluble in all known solvents and resists attack by most chemicals, although its surface is readily degraded by alkali metal-ammonia solutions. Such solvated electron media etch PTFE to produce a brown-black layer quite unlike the original white, low-friction, nonstick surface... 

Physical chemical studies of dilute alkali metal-ammonia solutions indicate the principal solution species as the ammoniated metal cation M+, the ammoniated electron e , the "monomer M, the "dimer" M2 and the "metal anion" M. Most data suggest that M, M2, and M are simple electrostatic assemblies of ammoniated cations and ammoniated electrons The reaction, e + NH3 - lf 2 H2 + NH2 is reversible, and the directly measured equilibrium constant agrees fairly well with that estimated from other thermodynamic data. Kinetic data for the reaction of ethanol with sodium and for various metal-ammonia-alcohol reductions of aromatic compounds suggest that steady-state concentrations of ammonium ion are established. Ethanol-sodium reaction data allow estimation of an upper limit for the rate constant of e + NH4+ 7, H2 + NH3. 

A large volume expansion for solutions of sodium in ammonia was first reported by Kraus and Lucasse (17). Since this initial report, many investigations have been made of the volume expansion for a number of alkali metal-ammonia solutions. The techniques employed in these investigations have varied from density measurements for concentrated solutions using the Westphal Balance or Pycnometer to dilatometric studies for dilute solutions, which measure the volume expansion directly. 

Table II is a summary of some of the comparative data for alkali metal-ammonia solutions.

In one paper, a new methodology for the remarkably selective reduction of organic molecules, possessing very negative reduction potentials, is developed. Due to the relatively simple reaction conditions, this method may be an interesting alternative to alkali metal-ammonia reductions. 

Since the first preparation of potassium-ammonia solution (Sir Humphrey Davy, in 1808) alkali metal-ammonia solutions have been at the centre of much theoretical and experimental interest. Novel properties include low density, high electrical conductivity, liquid-liquid phase separation, and a concentration driven metal-nonmetal transition [35]. 

The structure of Li and K ammonia solution has been recently studied by neutron diffraction experiments [36]. The results show, for saturated lithium-ammonia solutions, that the cation is tetrahedrally solvated by ammonia molecules. On the other hand, from the data of the microscopic structure of potassium-ammonia solutions, the potassium is found to be octahedrally coordinated with ammonia molecules. The Li+ is a structure making ion and K+ is a structure breaking ion in alkali metal-ammonia solutions [37, 38]. 

The combination of the reducing power of alkali metal-ammonia solutions with the strong complexing power of macrocyclic ligands allows compounds to be made containing unusual anions, such as [Sn9]4-. Among the unexpected products of such reactions are alkalide and electride salts. An example of an alkalide is [Na(2.2.2.crypt)]+ Na-, where crypt is the crypt and... 

Alkali Metal-Ammonia Initiator Systems. Beaman (4) first discovered that sodium in ammonia was capable of initiating the polymerization of methacrylonitrile. It should be recalled that sodium and ammonia alone... 

NIOSH REL (Chromium(VI)) TWA 0.025 mg(Cr(VI))/mh CL 0.05/15M SAFETY PROFILE Confirmed human carcinogen. Poison by subcutaneous route. Mutation data reported. A powerful oxidizer. A powerful irritant of skin, eyes, and mucous membranes. Can cause a dermatitis, bronchoasthma, chrome holes, damage to the eyes. Dangerously reactive. Incompatible with acetic acid, acetic anhydride, tetrahydronaphthalene, acetone, alcohols, alkali metals, ammonia, arsenic, bromine penta fluoride, butyric acid, n,n-dimethylformamide, hydrogen sulfide, peroxyformic acid, phosphorus, potassium hexacyanoferrate, pyridine, selenium. 

As in the case of the alkali metal-ammonia systems, the photoelectron spectra of negatively charged water clusters containing alkali metal atoms have been investigated for exploring the electronic structure of the metal atom in neutral clusters. In contrast to metal-ammonia systems, both the Na(3 S)-Na ( S) and Na(3 P)-Na ( S) transitions in the PE spectra of Na (H20) (n < 7) have been found to shift to the higher EBE (see Figure 3). The spectral shifts of the 3 S-type transition... 

CHROMIUM TRIHYDROXIDE (308-14-1) CrH204 A powerful oxidizer. Violent reaction with many materials, including reducing agents (explosion) hydrides, nitrides, and sulfides acetic acid, acetic anhydride acetone, alcohols, alkalis, alkali metals, ammonia, anthracene, arsenic, combustible materials dimethylformamide, ethers, ethyl alcohol fumes (ignition) finely divided metals hydrogen sulfide sulfuric acid organic matter peroxyformic acid, phosphorus, pyridine, selenium, sodium, sulfur, and other oxidizable materials. 

COBALT CHLORIDE or COBALT(II) CHLORIDE (7646-79-9 7791-13-1, hexahydrate) C0CI2 Noncombustible solid. Incompatible with bases, alkali metals, ammonia vapors oxidizers, acetylene reaction may be violent. Contact with acids or acid fumes can produce highly toxic chloride fumes. Aqueous solution is a weak acid. Incompatible with metals can cause pitting attack and stress corrosion in... 

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