Silver Nitrate In Methanol Research Articles

Trapping a Discrete [R2Sn(μ-OH)SnR2] Motif. Synthesis and Structural Characterization of [{(Phen)(NO3)Me2Sn(μ-OH)SnMe2(NO3)(Phen)}{NO3}] (Phen = 1,10-Phenanthroline)

The reaction of Me2SnCl2 with 2 equiv of silver nitrate in methanol followed by treatment with 2 equiv of water and 1 equiv of 4,4′-bipyridine in presence of 1,10-phenanthroline afforded the hydrol...

Synthesis, Characterization and Crystal Structure of Dimeric {[(AMTTO)2Ag]NO3}2 (AMTTO = 4‐Amino‐6‐methyl‐1, 2, 4‐triazine‐3(2H)‐thione‐5‐one)

AbstractThe reaction of 4‐Amino‐6‐methyl‐1, 2, 4‐triazine‐3(2H)‐thione‐5‐one (AMTTO, 1) with silver nitrate in methanol led to the dimeric complex {[(AMTTO)2Ag]NO3}2 (2). 2 was characterized by elemental analyses and IR spectroscopy as well as by X‐ray structure analysis. Crystal data for 2 at −80 °C: crystal system orthorhombic, space group P212121 with a = 1043.6(1), b = 1329.6(1), c = 2358.4(1) pm, Z = 8 and R1 = 0.037. The cation possesses a highly distorted linear coordination sphere in the solid state.

Gas Chromatographic Determination of Traces of O-Isobutyl S-2-(N,N-Diethylamino)ethyl Methyl Phosphonothioate (VX-Like Compound) in Working Area and Community Air

A gas-chromatographic procedure is proposed for the determination of O-isobutyl S-2-(N,N-diethylamino)ethyl methyl phosphonothioate (mixed ester) at the maximum permissible level for the working area air (5 × 10–6 mg/m3) and at the safe reference level of impact for the community air (5 × 10–8 mg/m3). The procedure is based on trapping the mixed ester from air by a chemisorbent. Next, the analyte is extracted by hexane; transformed to O-methyl-O-isobutyl methyl phosphonate by silver nitrate in methanol; and, in the case of the working area air, the methanol solution of the derivative is chromatographed. In the determination of the mixed ester in the community air, a solution of O-methyl-O-isobutyl methyl phosphonate (dialkyl methyl phosphonate) in methanol is passed through a column with an adsorbent and transferred to the chromatographic system with a thermal desorption system. The relative error of the determination of the mixed ester in the working area and community air is no more than 28 and 40 rel. %, respectively.

Gas-Chromatographic Determination of Trace Isobutyl S-2-(N,N-Diethylamino)ethyl Methylphosphonothioate (VX-like Compound) in Soil and Construction Materials

Procedures were developed for the determination of trace isobutyl S-2-(N,N-diethylamino)ethyl methylphosphonothioate (IBDAEMP) in soil and construction materials by gas chromatography at a level of 1 × 10–9%. The procedures are based on the extraction of IBDAEMP from test materials using an aqueous solution of monoethanolamine or chloroform saturated with ammonia, the back extraction of IBDAEMP into hexane, the evaporation of the hexane solution (with an addition of HCl) to dryness, the treatment of the residue with a solution of silver nitrate in methanol for obtaining O-isobutyl O-methyl methylphosphonate, and gas-chromatographic separation on an open tubular column with the HP–5MS chemically modified stationary phase with flame-photometric detection.

An imidazole-based P–N bridging ligand and its binuclear copper(I), silver(I) and palladium(I) complexes: synthesis, characterizations and X-ray structures

Reaction of 1-methylimidazole with n-BuLi in tetrahydrofuran at −78°C followed by addition of chlorodiphenylphosphine afforded a P–N bridging ligand, 2-(diphenylphosphino)-1-methylimidazole (dpim) in good yield. The structure of the ligand was determined by single crystal X-ray analysis. Reaction of a stoichiometric amount of the ligand with [Cu(MeCN) 4]ClO 4 in acetonitrile led to the binuclear complex [Cu 2(μ-dpim) 3(MeCN)](ClO 4) 2·2CH 3CN ( 1·2CH 3CN), whose structure was determined by single crystal X-ray analysis. The solid state structure shows that the two copper ions are held by three dpim ligands and the coordination geometry around each metal atom is different, one being three- and the other being four-coordinated. One of the copper ions forms a distorted tetrahedral array with two P and one N atoms from the dpim ligand and an additional N atom from an acetonitrile ligand, whereas the other copper ion is three coordinated with two N and one P atoms from the dpim ligand. The nitrate-bridged polymeric silver(I) complex, {[Ag 2(μ-dpim) 2(NO 3)](NO 3)} n ( 2) was prepared by the reaction of equimolar amounts of the ligand and silver nitrate in methanol and was characterized by IR, NMR and X-ray analysis. The dimeric unit, [Ag 2(μ-dpim) 2], possesses an eight-membered annular core structure with two ligands bridging the two metal ions in a head-to-tail configuration. Two types of nitrate ions are present in 2: one makes an infinite one-dimensional chain by joining the dimeric units through its two oxygen atoms in an anti– anti bridging mode whereas the other is disordered with a half occupancy and is located at the left and right sides of the chain. The dynamic behavior of 2 in acetone was also studied by variable temperature 31P NMR. The binuclear palladium(I) complex [Pd 2Cl 2(dpim) 2] ( 4) was prepared by a conproportionation reaction between complex [PdCl 2(dpim) 2] ( 3) and [Pd(dba) 2] (dba=dibenzylideneaceton). Only one geometric isomer, probably head-to-tail (HT), was formed in this reaction. Complex 3 was prepared by treating [PdCl 2(PhCN) 2] with two moles of ligand in dichloromethane solution. In this complex the ligand acts as a P-monodentate. In solution it exists as a mixture of cis and trans isomers.

Determination of Petroselinic,cis-Vaccenic and Oleic Acids in Some Seed Oils of the Umbelliferae by Silver Ion Thin Layer Chromatography of their Phenacyl Esters

A method is proposed for the determination of petroselinic, oleic and cis-vaccenic acids in plants of the Umbelliferae by using silver ion thin layer chromatography and densitometry. The fatty acids are first converted into phenacyl esters and this enables base line separation at ambient temperature on a plate impregnated with 1% methanolic silver nitrate. Conditions were found for the simultaneous determination of the saturated and dienoic fatty acids while maintaining the resolution of petroselinic and oleic acids. The procedure is suitable for screening plants of the Umbelliferae in phytochemical and selection studies, and may be of value as a small-scale preparative technique.

Determination of Petroselinic, cis-Vaccenic and Oleic Acids in Some Seed Oils of the Umbelliferae by Silver Ion Thin Layer Chromatography of their Phenacyl Esters

A method is proposed for the determination of petroselinic, oleic and cis-vaccenic acids in plants of the Umbelliferae by using silver ion thin layer chromatography and densitometry. The fatty acids are first converted into phenacyl esters and this enables base line separation at ambient temperature on a plate impregnated with 1% methanolic silver nitrate. Conditions were found for the simultaneous determination of the saturated and dienoic fatty acids while maintaining the resolution of petroselinic and oleic acids. The procedure is suitable for screening plants of the Umbelliferae in phytochemical and selection studies, and may be of value as a small-scale preparative technique.

Failure to demonstrate the true resection margins of excised skin tumours: a case for routine marking.

A solution of silver nitrate in methanol was used to assess the demonstration of the true surgical excision margin at histology of 100 skin excisions for basal cell carcinoma. In 15% of cases the true margin was not presented and deeper sections were required. The findings highlight the need for routine marking of excision specimens of neoplastic skin lesions to prevent incorrect diagnosis of incomplete excision based on a false resection margin.

Silver ion spray reagent for the discrimination of β- and ε-end groups in carotenoids on thin-layer chromatograms

Thin-layer chromatograms of pure carotenoids and natural carotenoid mixtures were dried and sprayed with saturated methanolic silver nitrate solution. Those carotenoids containing β-end groups showed a marked bathchromic colour change for each such end group. Thus, β-carotene, β-cryptoxanthin and zeaxanthin gave a clear red colour while α-carotene, α-cryptoxanthin and lutein gave deep organge spots after such treatment. Taraxanthin and antheraxanthin could be similarly distinguished. The method was not applicable to paper chromatography.

ChemInform Abstract: THE CHEMISTRY OF ARENE IMINES. IV. AN UNUSUAL SILVER PROMOTED TRANSFORMATION OF N‐CHLOROPHENANTHRENE 9,10‐IMINE INTO 9,10‐PHENANTHRENEQUINONE DIALKYL ACETALS

AbstractAus N‐Chlor‐phenanthren‐9,10‐imin (I) erhält man beim Behandeln mit Alkoholen (II) in Gegenwart von Silbersalzen die Phenanthrenchinon‐dialkylketale (III), die z.Tl. zum Chinon (IV) hydrolysieren.

Skeletal rearrangement of 3‐methoxy‐N‐chloromorphinan

Abstract3‐Methoxymorphinan (1) was converted to the corresponding N‐chloro derivative 2 by treatment with aqueous sodium hypochlorite. Upon exposure to methanolic silver nitrate, 2 was rearranged to the carbinolamine ether 3. In addition, considerable amounts of the dechlorinated morphinan 1 were formed. The structure of 3 was secured by spectral analysis and its degradation to the hexahydroindoline derivative 4. The observed skeletal rearrangement of 2 which requires the migration of an alkyl group is discussed in terms of a nitrenium ion.

Fatty acid composition of seed oils from sixAdansonia species with particular reference to cyclopropane and cyclopropene acids.

The oil content of sixAdansonia species (Bombacaceae family) of Madagascar (Adansonia grandidieri, A. za, A. digitata, A. fony, A. madagascariensis andA. suarenzensis) and Africa (A. digitata) ranges from 8 to 46%. All the oils give a positive response to the Halphen test. Malvalic, sterculic and dihydrosterculic acids were detected using gas liquid chromatography-mass spectrometry (GLC-MS). Epoxy or hydroxy fatty acids were not found in these oils. Fatty acid composition was determined by GLC using glass capillary columns coated with BDS and Carbowax 20 M. Results obtained for cyclopropenic fatty acids (CPEFA) were compared to those given by glass capillary GLC after derivatization with silver nitrate in methanol, by hydrogen bromide titration and by proton magnetic resonance (PMR). Good agreement was observed for the results given by the various methods. Malvalic acid content ranges from 3 to 28%, sterculic acid from 1 to 8% and dihydrosterculic acid from 1.5 to 5.1%. Odd-numbered fatty acids (Pentadecanoic and hepatadecanoic) were also observed in minute amounts (0.1-1.1%). Among the normal fatty acids, we observed mainly palmitic (21-46%), oleic (15-40%) and linoleic (12-32%). The relationship between fatty acid composition andAdansonia species is discussed.

Rearrangements of 8-chloro-8-methylbicyclo[4.2.0]oct-2-en-7-one

The endo- and exo-methyl isomers of 8-chloro-8-methylbicyclo[4.2.0]oct-2-en-7-one were separately treated with aqueous sodium carbonate, aqueous sodium hydroxide, silver nitrate in methanol, and sodium methoxide in methanol. A stereospecific ring contraction and an allylic substitution involving the enol form of the bicyclic ketone were found to be dependent on the base. Thermal rearrangement of the title compound resulted in the formation of propiophenone.

Mass spectrometry of the silver nitrate derivatives of cyclopropenoid compounds

1,2-dihexylcyclopropene, 1,2-diheptylcyclopropene, 1,2-dioctylcyclopropene, methyl malvalate, and methyl sterculate have been reacted with silver nitrate in methanol to form the corresponding methoxy and ketone derivatives. GLC, IR, and MS data are presented. The mass spectra and a possible method for determining the cyclopropene ring position are discussed.

Direct stripping voltammetric determination of lead, cadmium and zinc dithizonates

A procedure is described in order to determine lead, cadmium and zinc dithizonates by stripping voltammetry. The polarographic analysis is performed in a medium of methanol and benzene (chloroform) in a ratio of 7:1 and in the presence of silver dithizonate. Sodium nitrate was used as a base electrolyte. By carrying out these analytic conditions it is possible to perform directly the stripping voltammetric analysis in benzene (chloroform) solution of extracted dithizonates, without further treatment. Silver nitrate in methanol is added to dithizonates in order to free lead, cadmium, and zinc from their complexes, to be determined polarographically.

Changes in lipids of maturing Ceiba pentandra seeds

Lipids were extracted with chloroform-methanol from Ceiba pentandra seeds at different stages of maturity, separated by TLC and tested for the Halphen response. Cyclopropene fatty acids (CFA) were absent from mono- and diglycerides and phospholipids. Free fatty acids, diglycerides and phospholipids were maximum on the 23rd, 65th and 65th day respectively and minimum on the 96th day (mature) after flowering. The fatty acid compositions were determined by GLC. Dihydromalvalic acid reached a maximum value on the 81st day, while malvalic acid remained almost constant from the 38th day and sterculic acid steadily increased. Dihydrosterculic acid was noticed only in the free fatty acids and phospholipids. The positional distribution in the triglycerides was determined by lipolysis. Since CFA inhibited lipolysis partially the triglycerides were dissolved in chloroform and treated with methanolic silver nitrate prior to lipolysis. CFA were found in the 2-position, though to a lesser extent than in the primary positions, indicating rearrangement of glycerides during maturation.

Internuclear cyclisation. Part XXXII. Dienol–benzene and related rearrangements of some spirocyclohexadiene-lactams

The stereoisomeric 4′-hydroxy-2-methylisoindoline-1-spiro-1′-cyclohexadien-3-ones (1) rearrange with acid to give N-methylphenanthridinone (3) by migration of the aryl group and not of the nitrogen atom. However, similar reactions of the 2′-,3′-benzo- and 6′-hydroxy-4′-,5′-benzo-analogues [(21) and (7)] occur with predominant nitrogen migration. Brief exposure of compound (1) or (21) to methanolic acid results in the formation of cyclo-hexadienyl methyl ethers, presumably by way of intermediate cyclohexadienyl cations. It has not, however, been possible to identify a similar process in the acid-catalysed methanolysis of compound (7). The cyclohexadienyl ethers are also obtained when the corresponding cyclohexadienyl iodides are exposed to methanolic silver nitrate. Treatment of the stereoisomeric 4′-,5′-benzo-6′-iodo-compounds (34) with methanolic silver nitrate leads to one stereoisomer of the 6′-methyl ether (26) and to N-methylbenzo[c]phenanthridin-6-one (9). Stereospecific formation of the same isomer of (26) was observed when 2-(N-methyl-2-naphthylcarbamoyl) benzenediazonium sulphate was decomposed by heating in methanol. Possible factors controlling stereoselection in these reactions, and the competition between aryl and nitrogen migration, are briefly discussed.

Solvolyse von trans-13,13-dibrom-bicyclo[10.1.0]tridecadien-(4t.8t) und trans13,13-dibrom-bicyclo[10.1.0]tridecan

The gem-dibromocyclopropanes trans-13,13-dibromobicyclo[10.1.0]tridecadiene-(4t,8t) ( 1) and trans-13,13-dibromobicyclo[10.1.0]tridecane ( 2) undergo facile ring expansion during silver ion assisted solvolysis. Reaction of 1 and 2 with methanolic silver nitrate gave high yields of 1-methoxy-2-bromo-cyclotridecatriene-(2t,6t,10t) ( 3), and 1-methoxy-2-bromo-cyclotridecene-(2t) ( 5) respectively, while reaction with aqueous silver nitrate yielded 2-bromo-cyclotridecatriene-(2t,6t,10t)-ol ( 4), and 2-bromo-cyclo-tridecene-(2t)-ol ( 6) respectively. In no case were products found with cis double bonds. The stereochemistry of 3–6 was determined by NMR spectroscopy and by reduction.

Electrostriction in Mixed Polar Solvents: Viscosity of Silver Nitrate in Methanol—Water Mixtures at 30°C

Article Electrostriction in Mixed Polar Solvents: Viscosity of Silver Nitrate in Methanol—Water Mixtures at 30°C was published on December 1, 1969 in the journal Zeitschrift für Physikalische Chemie (volume 68, issue 3_6).

Gas‐liquid chromatographic analysis of cyclopropenoid fatty acids

AbstractA method is described for the analysis of cyclopropenoid fatty acids in oils. The method consists of reacting the methyl esters of the cyclopropenoid fatty acids with silver nitrate in methanol to form ether and ketone derivatives. The derivatives formed from the cyclopropenoid fatty acids are separated from the methyl esters of the normal fatty acids by gas‐liquid chromatography on a 15% diethylene glycol succinate column. The method is applicable to oils containing from 0.01% to 100% of cyclopropenoid fatty acids. The derivatives of oils containing lew levels of cyclopropenoids are separated from the normal methyl esters by alumina chromatography prior to gas‐liquid chromatography. Studies on the quantitative aspects of the derivative formation, alumina chromatography, and gas‐liquid chromatography are reported. Analyses for total cyclopropenoid fatty acid content of cottonseed oil andSterculia foetida oil by the gas‐liquid chromatographic and hydrobromic acid titration procedures showed good agreement. Replicate analyses of a sample ofSterculia foetida oil for malvalic and sterculic acid gave coefficients of variation of 6.04% and 1.17%, respectively.