Silver derivatives

This mechanism does not require a decision as to the question of whether the association of imidazole occurs through hydrogen bonding or by ionization. - However, if the methylation with diazomethane is considered together with methylations with dimethyl sulfate, dimethyl sulfate and alkali, and methyl iodide and the silver derivative of the imidazole, then such a comparison is best done using the hydrogen-bonded association model. 

The procedure described here for the preparation of succinimide silver salt is a modification of one reported for the formation of the silver derivative of maleimide. The alkylation step is modeled after the procedure of Comstock and Wheeler/ who prepared 2-ethoxypyrrolin-5-one in unspecified 3deld, and is an improvement over a later procedure developed in the laboratories of the submitters/ The general scheme has been successfully applied to the preparation of a variety of 2-ethoxypyrrolin-5-ones (Table 1) as well as 6-ethoxy- and 6-propoxy-4,5-dihydro-2(3H)-pyridone from the corresponding five- and six-membered cyclic imides/... 

In accordance with that, the silver derivative reacts with [NBu4][Au(CgF5)2] in the presence of pyridine to give the complex [Ag(py)3][Au(C6F5)2] py [132]. 

Similarly, another accident occurred when metallic silver came into contact with aziridine. According to the authors of the report, the accident was interpreted by the formation of an aziridine silver derivative. Comparing this behaviour with the one of ethylene oxide when silver is present, a danger which is of the same nature is demonstrated. The interpretation that had been given at the time was based on the presence of acetylene in ethylene oxide, whose silver derivatives are very sensitive explosives. It may be that acetylene traces were present in aziridine although none of the authors mentioned such as possibility as far as we know. 

The vapour readily explodes if superheated (above 200°C), and the silver derivative explodes on heating. 

Ethylenimine Brochure 125-521-65, Midland (Mich.), Dow Chemical Co., 1965 Explosive silver derivatives may be formed in contact with silver or its alloys, including silver solder, which is therefore unsuitable in handling equipment. 

It tends to explode during analytical combustion, and the copper(I) and silver derivatives decomposed violently (with occasional explosion) on rapid heating. 

Interaction in ammoniacal solution gives the silver derivative which ignites around 150°C. 

The silver derivative of dithizone decomposes explosively at higher temperatures. 

Hydrothermal synthesis and characterization of perchlorate enclathrated sodalite Na8[GaSi04]6 (C104)2 and silver derivatives of the type Na8 xAgx [GaSi04]6(C104)2... 

One possible explanation is that, in silver derivatives the Ga-0 and Si-0 distances and also the Ga-O-Si angles are considerably modified compared to other sodalites. Since these distances and the Ga-O-Si angles are thought to be very important for the observed frequencies, this could be an explanation for the observed shift as reported by A.V. Borhade et al [10],... 

Catalytic forms of copper, mercury and silver acetylides, supported on alumina, carbon or silica and used for polymerisation of alkanes, are relatively stable [3], In contact with acetylene, silver and mercury salts will also give explosive acetylides, the mercury derivatives being complex [4], Many of the metal acetylides react violently with oxidants. Impact sensitivities of the dry copper derivatives of acetylene, buten-3-yne and l,3-hexadien-5-yne were determined as 2.4, 2.4 and 4.0 kg m, respectively. The copper derivative of a polyacetylene mixture generated by low-temperature polymerisation of acetylene detonated under 1.2 kg m impact. Sensitivities were much lower for the moist compounds [5], Explosive copper and silver derivatives give non-explosive complexes with trimethyl-, tributyl- or triphenyl-phosphine [6], Formation of silver acetylide on silver-containing solders needs higher acetylene and ammonia concentrations than for formation of copper acetylide. Acetylides are always formed on brass and copper or on silver-containing solders in an atmosphere of acetylene derived from calcium carbide (and which contains traces of phosphine). Silver acetylide is a more efficient explosion initiator than copper acetylide [7],... 

The reaction can be followed by adding an aliquot to eth-anolic silver nitrate solution (Note 9). The reaction is complete when no precipitate of the silver derivative is obtained. Also the disappearance of the infrared absorption band at 3300 cm. (3.03 fx) (ethynyl z)CH) can be followed with carbon tetrachloride extracts of aliquots. 

The stabilized versions of (99)-(101) have easily been obtained from the silver derivative (103), shown in Scheme 31 [212], Treatment of (103) with ClAu(tht) gives (104), which can be oxidized to give the dinuclear complexes (105) and (106) [213], Interestingly, treatment of (103) with Pd precursors gives complexes in which the bis-yUde is always behaving as a chelate [214],... 

The procedure to fabricate colloidal silver, (Ag°) , spherical nanoparticles is similar to that already described (see Section 9.3.3) The Cu( AOT)2 is replaced by the silver derivative. The relative concentration of Na(AOT), Ag(AOT)2, and the reducing agent remain the same. Control of the particle size is obtained from 2 nm to 6 nm (67). To stabilize the particles and to prevent their growth, 1 p.l/mL of pure dodecanethiol is added to the reverse micellar system containing the particles. This induces a selective reaction at the interface, with covalent attachment, between thio derivatives and silver atoms (68). The micellar solution is evaporated at 60°C, and a solid mixture of dodecanethiol-coated nanoparticles and surfactant is obtained. To remove the AOT and excess dodecanethiol surfactant, a large amount of ethanol is added and the particles are dried and dispersed in heptane. A slight size selection occurs, and the size distribution drops from 43% to 37%. The size distribution is reduced through the size selected precipitation (SSP) technique (38). 

Arginine has been precipitated (a) in the form of its silver derivative at pH io 1 (b) as its dinitronaphtholsulfonate which is then decomposed by means of 33 per cent sulfuric acid,2 by the combined action of hot dilute sulfuric acid and butyl alcohol,3 by cold concentrated hydrochloric add followed by aniline,4 or by barium hydroxide.5 Arginine has likewise been precipitated... 

Characterization of the essential oils of onion and garlic was aided by the isolation of silver derivatives. The salts containing n-propanethiol and allyl thiol were both insoluble and could not be recrystallized.296... 

Cerussite is of secondary origin, being found associated with other lead minerals, and is widely distributed. There are many European and American localities. Fine crystals have been obtained from Phocnixvillc. Pennsylvania Joplin. Missouri Leadville. Colorado Pima County, Arizona, and Dona Ana County, New Mexico. It is an ore of lead, and frequently carries values of silver. Derived from the Latin cetussa. white lead... 

Well-cooled sulphuryl chloride, diluted with 15-20 vols. of chloroform, is sat. with dry ammonia, the precipitated product dissolved in water, the soln. acidified with nitric acid, and the whole of the chlorine precipitated with silver nitrate the filtered soln. is neutralized with alkali, treated with silver nitrate, and the crystalline precipitate, which consists of silver sulphimide and some other silver derivative, separated by filtration. After adding a further quantity of silver nitrate, the clear soln. is treated with alkali, when silver sul-phamide is obtained as a colourless, amorphous precipitate, which, however, is invariably mixed with some other silver compound, probably the same as that present in the silver sulphimide precipitate. In order to remove this impurity, the well-washed precipitate is treated with hydrochloric acid in quantity exactly sufficient to convert the silver into chloride, and the strongly acid soln. is neutralized with ammonia and mixed with silver nitrate, when only the silver compound of unknown composition is precipitated pure silver sulphamide can now be precipitated by adding silver nitrate and excess of ammonia, and on decomposing this compound with the necessary quantity of hydrochloric acid, a neutral or feebly acid soln. of sulphamide is obtained. Sulphamide is deposited in large, colourless crystals when its aq. soln. is evaporated over sulphuric acid under reduced press. 

Dequidt J, Vasseur P, Gromez-Potentier J. 1974. [Experimental toxicological study of some silver derivatives]. Bulletin de la Societe de Pharmacie de Lille 1 23-35. (French). 

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