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Topic: Diazonium salt

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	DIAZO COMPOUNDS - LoveToKnow Article on DIAZO COMPOUNDS (Site not responding. Last check: 2007-10-14)
		The diazonium salts are characterized by their great reactivity and consequently are important reagents in synthetical processes, since by their agency the amino group in a primary amine may be exchanged for other elements or radicals.
		On mixing dilute solutions of the diazonium hydroxide and the alkali together, it is found that the molecular conductivity of the mixture is much less than the sum of the two electrical conductivities of the solutions separately, from which it follows that a portion of the ions present have changed to the non-ionized condition.
		Hantzsch explains the characteristic reactions of the diazonium compounds by the assumption that an addition compound is first formed, which breaks down with the elimination of the hydride of the acid radical, and the formation of an unstable syn-diazo compound, which, in its.turn, decomposes with evolution of nitrogen (Ber., 1897, 30, p.
	www.1911encyclopedia.org /D/DI/DIAZO_COMPOUNDS.htm (2437 words)

	Patent 4468467: Diazonium salt for bilirubin assay
		Diazonium salts which are useful in an assay for bilirubin are disclosed.
		The diazonium salts are less shock sensitive than comparable diazonium salts of the prior art and yet retain the ability to couple with bilirubin to produce azobilirubins.
		The diazonium salts of the present invention are useful in conventional solution assays and in dry analytical elements.
	www.freepatentsonline.com /4468467.html (4013 words)

	DIAZO COMPOUNDS - Online Information article about DIAZO COMPOUNDS (Site not responding. Last check: 2007-10-14)
		Replacement of NH2 by halogens and by the CN and CNO groups:The diazonium salt is warmed with an acid solution of the corresponding cuprous salt (T. Sandmeyer, Bee., 1884, 17, p.
		The potassium salt of the iso-diazo hydroxide yields on methylation a nitrogen ether, RN(CH3)NO, whilst the silver salt yields an oxygen ether, RN: NOCH3.
		This salt is a colourless crystalline substance of composition CH 30.C6H4.N2.CNHCN2H20, and has the properties of a metallic salt; it is very soluble in water and its solution is an electrolyte, whereas the solutions of the synand anti- compounds are not electrolytes.
	encyclopedia.jrank.org /DEM_DIO/DIAZO_COMPOUNDS.html (1613 words)

	Method of forming a positive photoresist pattern utilizing contrast enhancement overlayer containing ... (Site not responding. Last check: 2007-10-14)
		The aromatic diazonium salt of the present invention is obtained, for example, by treating an aromatic amino compound with an alkyl nitrite in the presence of trifluoromethanesulfonic acid.
		Conventional diazonium salts have the problem that they contain metal or semimetal and they have the further problem that they are generally low in solubility in solvents which dissolve the polymer compound having an acid labile group.
		Since these diazonium salts are all good in photobleaching property, when pattern is formed using the radiation sensitive composition of the present invention, a light sufficiently reaches lower portion of film at exposure, resulting in pattern of high contrast and of excellent shape.
	www.patentstorm.us /patents/5290666.html (5775 words)

	diazonium salt -- Encyclopædia Britannica
		Diazonium salts are usually prepared by the reaction (diazotization) of primary amines with nitrous acid; their most striking property is their instability.
		Aryl diazonium salts (ArN+N, where Ar denotes an aromatic ring) are especially useful starting materials for preparing aryl halides because they provide access to aryl fluorides, chlorides, bromides, and iodides.
		Aryl diazonium salts are prepared by diazotization, a procedure in which a primary aromatic amine (ArNH2) is treated with a source of nitrous acid (HNO2).
	www.encyclopaedia.britannica.com /eb/article?tocId=9030311 (735 words)

	Patent 4288520: Process of manufacturing light-sensitive copying material based on diazonium salt condensation products
		A process as claimed in claim 2 wherein the water-insoluble polymer is a homopolymer or copolymer of an alkyl acrylate or alkyl methacrylate with 4 to 12 carbon atoms in the alkyl group, or of a vinyl ester, or is a copolymer of dibutyl maleate.
		They are in general prepared by condensation of a polynuclear aromatic diazonium compound, preferably of substituted or unsubstituted diphenylamine-4-diazonium salts, with active carbonyl compounds, preferably formaldehyde, in a strongly acid medium, preferably concentrated phosphoric acid.
		and the decomposition temperature of the diazonium compound.
	www.freepatentsonline.com /4288520.html (3037 words)

	3-substituted pyridine compounds and related synthesis - US Patent 6509471 (Site not responding. Last check: 2007-10-14)
		A process of claim 3, where the diazonium salt of formula II is prepared by reacting 3-amino-2-chloropyridine with an alkyl nitrite and an acid in the presence of a solvent.
		The pyridinediazonium salt of formula II is useful as an intermediate for the preparation of the compounds of formula I.
		By "addition salts" are meant salts of a given compound (or salt) of the invention derived from the chemical interaction with inorganic acids or organic acids.
	www.patentstorm.us /patents/6509471.html (3383 words)

	MSN Encarta - Search Results - diazonium salt
		Salt (diet) chemical compound, sodium chloride (NaCl), a vital constituent of the human body.
		Salt is used to enhance the flavor of foods and to...
		Strategic Arms Limitation Talks (SALT), negotiations that began in November 1969 between the United States and the Union of Soviet Socialist...
	encarta.msn.com /diazonium+salt.html (123 words)

	[No title]
		The diazonium salts produced tend to be unstable and are not usually isolated.
		For that reason, diazonium salts are always freshly prepared and used immediately in the coupling reaction.
		[Diazonium salts should never be allowed to dry out!] The mechanism of the reaction involves protonation of the nitrous acid generated in situ.
	web.uccs.edu /bgaddis/chem332/chem334/DiazoDyesHandOut.doc (2036 words)

	Bandwidth Market, Ltd (Site not responding. Last check: 2007-10-14)
		The amount of aromatic diazonium salt is preferably in the range of from 5 to 20% by weight based on the water-soluble polymer.
		When the amount of the aromatic diazonium salt is too small, the sensitivity is not increased, and when it is too large, the salt is likely to precipitate.
		It is therefore considered that when an aromatic diazonium salt is incorporated into a system containing the water-soluble polymer and dichromate, the optical reduction by light irradiation is promoted, and as the result, the photosensitivity of composition is enhanced.
	www.telequipment.com /resources/patents/data1/5173382.html (2271 words)

	Patent 4511642: Photo-fixing heat-sensitive recording media with photosensitive diazonium salt, coupler, and organic ...
		In the practice of the invention, all the components such as diazonium salts, couplers and optionally, basic materials, or diazonium salts and couplers having basic functional groups therein should be insoluble or sparingly soluble in water and at least one component should be present in the form of a fine powder with a certain size.
		The diazonium salts, couplers, basic materials, basic group-bearing couplers and insolubilizing or sparingly solubilizing agents for diazonium salts may be used singly or in combination of two or more, respectively.
		The diazonium salts, couplers, basic materials and couplers having basic groups are dispersed in water, or are dissolved in organic solvents such as alcohols, acetone, MEK, ethyl acetate and the like singly or in combinations of two or more.
	www.freepatentsonline.com /4511642.html (3253 words)

	Organic Chemistry (Site not responding. Last check: 2007-10-14)
		Diazonium compounds are produced by reacting aromatic amines, particularly phenylamine, with nitrous acid, also known as nitric(III) acid.
		Coupling is the reaction of a diazonium salt with an activated aromatic compound.
		The ammonium salt is not actually produced, but in the case of acid hydrolysis, the ammonium salt of the mineral acid and the carboxylic acid.
	www-jcsu.jesus.cam.ac.uk /~rpc25/notes/chemistry/organic/index.html (3229 words)

	Diazonium Coupling Reaction (Site not responding. Last check: 2007-10-14)
		The purpose of this lab is to perform an aromatic electrophilic substitution reaction using an arenediazonium salt to prepare an azobenzene derivative.
		Although the salts are not very reactive, they can accomplish electrophilic substitution if the arene substrate is activated by a suitable electron donating substituent.
		Diazonium salts are explosive when dry, and therefore are generally not isolated.
	www.owlnet.rice.edu /~chem215/MethylRed.html (1216 words)

	Micellar-Promoted Homolytic Dediazoniation of p-Nitrobenzenediazonium Tetrafluoroborate
		A substantial fraction of diazonium ions are bonded to the micellar aggregates, and formation of strong ion-pairs between PNBD and the sulfate headgroup of the surfactants is not significant.
		In this work, the presence of potential reducing agents was minimized by careful purification of the diazonium salt and by use of materials of the maximum purity available.
		As noted, dediazoniations of aromatic diazonium ions involve a variety of mechanisms and slight modifications in the reaction system can lead to entirely different reaction products, suggesting fundamentally different dediazoniation mechanisms, and this opens a number of other possibilities that must be taken into consideration.
	pubs.acs.org /cgi-bin/jtextd?langd5/16/i01/html/la9901682 (5535 words)

	[Azoindoxyl methods for the investigation of hydrolases. IV. Suitability of various diazonium salts (author's transl)]. (Site not responding. Last check: 2007-10-14)
		Suitability of various diazonium salts (author's transl)].Using fresh frozen, freeze-dried or cryostate sections from aldehyde fixed rat tissues 13 diazonium salts were tested as simultaneous coupling reagents for the localization of acid, neutral and alkaline hydrolases with azo indoxyl methods.
		Hexazotized new fuchsine and/or Fast blue B are the diazonium salts of choice for the demonstration of acid beta-galactosidase, neuraminidase, beta-N-acetylglucosaminidase, acid phosphatase, and non-specific esterase followed by hexazotized p-rosaniline.
		On the average 0.01-0.02 ml unstable diazonium salt/ml and 0.3--1 microgram stable diazonium salt/ml are sufficient for the correct localization of these hydrolases.
	www.pdg.cnb.uam.es /UniPub/iHOP/gp/3165283.html (352 words)

	[No title]
		The diazonium salt was added to a mixture of sodium iodide and water to produce the product, 4-Iodonitrobenzene.
		The diazonium salt solution was then added to a solution of sodium iodide (2.25g) in water (10ml) in a large beaker.
		The temperature was kept below 10(C as much as possible I order to ensure the stability of the diazonium salt solution and, judging by the high yield, the temperature regulation worked quite well.
	www.maths.tcd.ie /~pwalsht/labs/Organic_Labs_4.doc (347 words)

	John Thomas' note of Pharmaceutical Industry (Site not responding. Last check: 2007-10-14)
		The free acids of penicillins are generally unstable and are converted into a metal salt by extraction with alkali, followed by freeze-drying of the extract, or by addition of a concentrated solution of a metal salt such as potassium acetate, whereby the potassium salt of the penicillin is precipitated.
		A method other than arsonation that achieves the same result is Bart's reaction, in which a diazonium salt is coupled with an alkali arsenite, usually in the presence of a catalyst such as copper powder.
		Salicylic acid is used in medicine as the free acid, as its acetyl derivative, aspirin, and as its salts, of which the most important is sodium salicylate, used in the treatment of rheumatism.
	personal.vsnl.com /johnthomas/pharma (9973 words)

	Chemicals.com
		The salt sector includes snow-clearing salt, sea salt, cooking salt, table salt and livestock salt.
		Salt and prodem accounted for 97% of 1996 revenues and other, 3%.
		Producer of materials and chemicals, including powdered acrylics, dielectric imaging materials, diazonium salts and compounds, screen print materials and chemicals, absorbant resins, fine organic materials and chemicals, solder fluxes, powder polystyrenes, and fine beads.
	www.chemicals.com (7275 words)

	Practical and Scaleable Syntheses of 3-Hydroxythiophenol - [www.rhodium.ws]
		Nucleophilic displacement of the diazonium group with a sulfur nucleophile readily yields the thiol.
		The success of this approach is hinged on the protection of the thiol group prior to the diazonium salt formation, to avoid its potentially hazardous reaction with the diazonium salt.
		The diazonium salt soln was then added to the refluxing sulfuric acid at such rate that the internal temperature could be kept between 120-124°C. Heating was removed shortly after the completion of addition and the flask was cooled to ca.
	www.erowid.org /archive/rhodium/chemistry/3-hydroxythiophenol.html (2958 words)

	Patent 4902601: Radiation sensitive polymeric diazonium salt and methods of making the polymeric diazonium salt
		In order to effect conversion of the remaining isocyanate groups, a solution of 4-aminophenylacetic acid sodium salt (1.7 g) in NMP (10 ml) was added quickly and the mixture was stirred at 40.degree.-50.degree.
		In order to effect conversion of the remaining isocyanate groups, a solution of 4-aminophenylacetic acid sodium salt (1.7 g) in NMP (10 ml) was added quickly and the mixture was stirred at 50.degree.
		The diazo content of the two polymers, taken as the UV absorbance of a 0.002% w/v solution at 380 nm, was the same (0.43), but polymer No. 27 contained additional carboxylic acid groups.
	www.freepatentsonline.com /4902601.html (4502 words)

	[No title]
		In order to remove the chromium salts as completely as possible, the crude nitrobenzoic acid is warmed on the water bath and agitated with 1 l.
		If the sodium sulfite-diazonium salt mixture is acidified before warming or before becoming dark, the red color of the solution does not disappear on heating, and the precipitated phenylhydrazine hydrochloride obtained is colored red.
		The rapid addition of the diazonium salt solution to the sodium sulfite seems to be advantageous.
	www.netidea.com /~queequeg/how-to/rgsyn10.txt (17586 words)

	o-CHLOROTOLUENE AND p-CHLOROTOLUENE
		The cold diazonium solution is now poured rapidly into the well-stirred cuprous chloride solution.
		If the mixture obtained by adding the diazonium solution to the cuprous chloride solution is heated at once, the yield falls to 55–65 per cent.
		and by the diazotization of o-toluidine followed by replacement of the diazonium salt group by chlorine.
	www.orgsyn.org /orgsyn/orgsyn/prepContent.asp?prep=cv1p0170 (732 words)

	Howstuffworks "What exactly is a blueprint?" (Site not responding. Last check: 2007-10-14)
		In the diazotype method, the paper is light-sensitized with a mixture of a diazonium salt (used in the manufacture of dyes), a reactant, and an acid that keeps the diazonium salt and the reactant from reacting with each other.
		The semi-transparent original is placed on top of the sensitized paper, and a copy of the same size as the original is made by direct contact.
		Ammonia gas or solution is used as a developer after exposure -- it neutralizes the acid and allows the remaining diazonium salt to combine with the reactant to create a blue dye.
	ibs.howstuffworks.com /ibs/orlwx/question321.htm (381 words)

	making diazonium salts from phenylamine (aniline)
		If you want to know about the reactions of the diazonium ions formed, you will find a link at the bottom of the page.
		The reactions of a diazonium salt are always done with a freshly prepared solution made in this way.
		Diazonium salts are very unstable and tend to be explosive as solids.
	www.chemguide.co.uk /organicprops/aniline/makediazo.html (462 words)

	Light-sensitive mixed diazonium condensate printing plate for waterless offset printing - US Patent 4775607 (Site not responding. Last check: 2007-10-14)
		The printing plate can be readily developed with developers which contain organic solvents, to give printing forms with good resolution, good ink repellency in the background areas, and long print runs.
		X and B units which are mutually linked by bridge members derived from carbonyl compounds capable of condensation, A being the radical of an aromatic diazonium compound capable of condensation with formaldehyde, and B being the radical of a compound that is free of diazonium groups and that is capable of condensation with formaldehyde.
		A light-sensitive printing plate as claimed in claim 1, wherein said silicone elastomer is a multicomponent elastomer of the addition type or the condensation type.
	www.patentstorm.us /patents/4775607.html (609 words)

	General Chemistry Online: Glossary:
		A diazonium salt is a compound with general form Ar-N
		Diazonium salts are unstable and explosive in dry form.
		Diazotization is a reaction that converts an -NH group connected to a phenyl ring to a diazonium salt.
	antoine.frostburg.edu /chem/senese/101/glossary/d.shtml (1121 words)

	EPSRC Web Site - Grants on the Web (Site not responding. Last check: 2007-10-14)
		The objectives of this research are the design of dual catalysts for the preparation and direct in-situ reaction of diazonium salts and diazo compounds.
		Although these reactive compounds are of considerable general use in synthesis, their application has the downside of considerable hazard and, in consequence, their chemistry is under-utilised on a large scale.
		It is proposed that combinations of lanthanide or early transition metal salts with palladium or rhodium complexes should be able to convert stable precursors such as imines or amines, via diazoalkanes and diazonium salts, directly into diverse targets such as biaryls, stilbenes and cyclopropanes, etc.
	gow.epsrc.ac.uk /ViewGrant.aspx?Grant=GR/M77048/01&bannerlink=Programme%20support (121 words)

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