Alkynylhalocarbenes. 2. Generation of (alkyn-1-yl)-chlorocarbenes by basic solvolysis of 1,1-dichloro-2-alkynes and their reaction with olefins: Synthesis of 1-chloro-1-alkynylcyclopropanes

1,1-Dichloro-2-alkynes R¹CCCHCl₂ (4a–g; R¹=Me, n-Pr, c-Pr, t-Bu, Ad, Nor, Ph) were synthesized with yields of 50–75% by chlorination with PCl₅ of formylacetylenes (3a–g), prepared by oxidation of propargyl alcohols (1a–d) with CrO₃·Py·HCl complex or acidolysis of propargyl acetals (2a–c) in the presence of catalytic quantities of pyridine; the corresponding alkynylchlorocarbenes, R¹CCCCl (5a–g) were generated from them with powdered KOH in a two-phase system or t-BuOK. The latter were trapped by olefins with formation of 1-chloro-1-alkynylcyclopropanes (6a–t) with yields of up to 90%.See [1] for Communication 1.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1128–1135, May, 1992.     

Electrosurface and Ion-Selective Properties of Track-Etched Nanofilters: The Effect of Polyvalent Metal Adsorption

The effect of polyvalent metal adsorption on the performance and ion selectivity of poly(ethylene terephthalate) track-etched membranes with pores of 10 nm in diameter was studied. Membrane samples were prepared from the track-etched membranes with pores of 20 nm in diameter by thermal shrinkage. It was shown that an effective pore diameter decreases and selectivity of track-etched membranes increases upon filtration of Al(NO₃)₃ and Cr(NO₃)₃ solutions. The results obtained are explained by ion adsorption leading to the formation of complexes between polyvalent metals and carboxyl groups on the pore surface that is confirmed by IR spectroscopy data. The study of electrosurface properties of modified membranes and the dependence of ion selectivity of track-etched membranes on the concentration of Al³⁺ ions in 10^–2 M KCl solution indicates the decrease of membrane negative surface charge resulted from Al³⁺ adsorption and membrane charge reversal at Al³⁺ concentration in a solution higher than 10^–6 M. The dependences of the ion selectivity on pH and Al³⁺ concentration C _Al in a solution are similar. At pH < 3 and C _Al > 10^–6 M, the _1–2 > _1–1 > _2–1 ion selectivity series characteristic of the initial negatively charged membranes for the 1–1, 1–2, and 2–1 electrolyte solutions is reversed into the _2–1 > _1–1 > _1–2 series characteristic of positively charged membranes.     

Photometric detection of cyclodextrins in liquid chromatography by using iodine generated electrochemically in-situ

A method has been developed for photometric detection of cyclodextrins (CD) in liquid chromatography using iodine (I₂) generated electrochemically in-situ. Iodide ion in the mobile phase was electrochemically oxidized to I₂ which was subsequently reacted with I^–, in an electrochemical flow cell, forming I₃^–. The absorbance of I₃^– was found to be greatly enhanced when CD were present in the mobile phase. The absorbance enhancement was caused by the change in the mole fraction of I₃^–, because of the inclusion reaction of I₃^– with CD. On the basis of this phenomenon, CD were detected by means of a photodiode-array UV–visible detector positioned downstream of the electrochemical flow cell. The signals were found to be linearly dependent on CD concentration. Because the formation constants of I₃^– with CD decrease in the order -CD>-CD>-CD, -CD was most detectable by the method. Detection limits were 1.0 mol L^–1 for -CD, 65 mol L^–1 for monoG1--CD, 100 mol L^–1 for -CD, and 200 mol L^–1 for -CD.     

Copper(II) halide reactions with the - NH · CS - group in heterocyclic pentaatomic rings

Summary White crystalline complexes of general formula Cu₂L₄X₂ (where X = Cl, Br and L = 1, 3-oxazolidine-2-thione, pyrrolidine-2-thione,N-methyl-1,3-imidazolidine-2-thione andN-ethyl-1,3-imidazolidine-2-thione) and CuLX (where L = 1,3-imidazolidine-2-thione) were prepared by reduction of copper(II) halides and studied by i.r. spectroscopy in the 4000–200 cm^– range. Evidence for ligand coordination to the metal through sulphur was found in each case. The(CuCI) vibration in all the chloro derivatives falls atca. 240 cm^–.     

Nucleophilic substitution in dibenz[b,d]iodolium and 11,12-dihydro-10H-dibenz[b,g]iodocinium cations

Treatment of dibenz[b,d]iodolium tetrafluoroborate with NO₂ ^–, Br^–, and N₃ ^– ions gave, along with nucleophilic substitution products, 2-nitro-, 2-bromo-, and 2-azido-2-iodiphenyls, diphenyl, 2-iododiphenyl, and 2,2-diiododiphenyl (products of one electron reduction), whereas 11,12-dihydro-10H-dibenz[b,g]iodocinium tetrafluoroborate underwent nucleophilic substitution with all three nucleophiles to give a single product in each case: 1-(2-nitrophenyl)-, 1-(2-bromophenyl)-, or 1-(2-azidophenyl)-3-(2-iodophenyl)propane.M. V. Lomonosov Moscow State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 405–412, March, 1998.     

Electrochemical characteristics of H2O2 microarray electrodes as base elements of biosensors

Summary The electrochemical characteristics were examined of band- and square-type MAEs (microarray electrodes) with 10, 20 and 30 m band width and side length prepared by using standard planar processing in K₃Fe(CN)₆ solution. Among them, S1–5 square-type MAE with 10 m side length and 9.0×10^–3 mm² in the total area exhibits the largest current density and the shortest response time. The H₂O₂ calibration curve obtained at the S1–5 shows linearity from 0.1 to 5.0 mmol/l, a mean slope of 550 nA/mmol/l with a CV (variation coefficient) of 16.1%. A glucose sensor based on the S1–5 was prepared and its sensitivity was 21 nA/mmol/l, ten-fold greater than that of a single ME (microelectrode) reported lately.     

Nitrogen Trichloride Decomposition in the Presence of Molecular Hydrogen: I. Promotion of Nitrogen Trichloride Decomposition by Molecular Hydrogen Additives Near the Lower Self-Ignition Limit

The promotion of the branched-chain decomposition of nitrogen trichloride by molecular hydrogen additives at room temperature and 20 torr manifests itself in a decrease in the induction period and the acceleration of reactant consumption with an increase in the hydrogen concentration in the NCl₃+ H₂+ He mixtures. The emission spectrum of the H₂+ NCl₃flame contains the intense bands of NCl (b ¹⁺– X ^3–, = 1 – 0, = 0 – 1, and = 0 – 0, where is the vibrational quantum number) and the bands of a hydrogen-free compound. The latter bands can be assigned to electronically excited NCl ₂radicals formed in the H + NCl₃reaction. The calculations restrict the number of elementary reactions favoring promotion. The promotion effect in the system studied should be due to the side reaction of linear branching. The occurrence of the H + NCl₃reaction via two pathways (NHCl + 2Cl and NCl ₂+ HCl) ensures the qualitative agreement between the experimental data and calculation.     

Cycloaddition to 3h-1,2-dithiole-3-thiones. X-ray structural investigation of 2,3,4′,5′-tetracarbonmthoxy-5-methyl-6-phenylthio-pyran-4-spiro-2′-(1,3-dithiole)

Treatment of 4-methyl-5 -phenyl-3H-1,2-dithiole-3-thione with dicarbomethoxyaceotene gave 2,3,4,5-tetra-carbomethoxy-5-methyl-6-phenylthiopyran-4-spiro-2-(1,3-dithiole) whose structure was proved by x-ray investigation.K. A. Timiryazev Agricultural Academy, Moscow 127550. A. N. Nesmeyanov Institute of Organoelemental Compounds, Russian Academy of Sciences, Moscow 117813. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 908–914, July, 1994.     

Research on 1-aza two-ring systems

Reduction of 5-[2-(methoxycarbonyl)ethyl]-1,3-dihydropyrrolizines with lithium aluminum hydride gave 5-(-hydroxypropyl)-1,2-dihydropyrrolizines (in 70–90% yields), which have intramolecular -hydrogen bonds in dilute solutions. The parameters of the -hydrogen bonds were determined in the IR spectra, and their enthalpies were found. The data obtained (_OH 95–99 cm^–1, –H 3.05 kJ·mole^–1) show that among compounds with an aliphatic hydroxyl group and a system of electrons, 5-(-hydroxypropyl)-1,2-dihydropyrrolizines have some of the strongest intramolecular -hydrogen bonds.See [1] for communication XVI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 359–363, March, 1978.     

Synthesis of tetrahydrodibenzodipyrazolo-[1,2,5,8,9,12]- and-[1,2,5,6,9,12]-hexaazacyclotetradecine derivatives

The reaction of nickel(II) nitrate with 4-(2-bromo-4-methyl-1-phenylazo)-3-amino-5-methy1-2-alkylpyrazoles by refluxing in dimethylformamide in the presence of K₂CO₃ followed by purification with a column filled with Al₂O₃ gave [1,10,11,20-tetrahydro-1, 11-dipropyl-3,8,13,18-tetramethyIdibenzo[c,j]dipyrazolo[3,4-f:3,4-m] [1,2,5,8,9,12]hexaazacyclotetradecinato(2-)-4,10,14,20]nickel and [1,14,15,20tetrahydro-1, 14-dipropyl-3,7,12,17-tetramethyldibenzo[c,j]dipyrazolo[4,3-g:3,4-m] [1,2,5,6,9,12]hexaazacyclotetradecinato(2-)-5,10,15,20]nickel, which were characterized by the results of elementary analysis and the IR, UV, PMR, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1097–1103, August, 1978.     

An upper bound to bond electric dipole moments

An upper bound can be set to the dipole moment of the X-H bond (with X+H^– polarity) for symmetrical molecules of XH₄ and XH₃ type from the experimental values of the g factor and bond length. The following upper bounds have been found to the bond dipole moments: CH₄ (C+H^–<0.902 D, SiH₄, (Si+H^–)<4.21 D, GeH₄+ (Ge+H^–)<3.59 D, NH₃ (N+H^–)<0, PH₃ (P+H^–)<2.74 D. These results enable one to rule out certain published data on the dipole moment of the C-H bond in methane as certainly incorrect. In the case of the ammonia molecule, the possibility of N+H^– polarity is ruled out.Translated from Teoreticheskaya i Éksperimental'naya Khitniya, No. 3, pp. 346–350, May–June, 1985.     

Synthesis and characterization of some methyl complexes of palladium(II). Part 2(1)

Summary Dichloro complexes of Pd^II, [Pd(L–L)Cl₂], where L–L=1-(thiomethyl)-2-(diphenylarsino)ethane (S–As) or 1-(thiomethyl)-2-(diphenylphosphino)ethane (S–P) andtrans-[PdL₂Cl₂], where L=diphenyl(2-phenylethyl)-phosphine (PE), diphenyl(1-naphthyl)phosphine (PN) orN-methyl-2-thiophenealdimine (SN), have been prepared and characterized. The reactions of these complexes with MeLi were investigated. The dimethyl complexes [Pd(L–L)Me₂] (L–L=S–As, S–P) and [Pd(PE)Me₂] were isolated and characterized. Reaction of [Pd(L–L)Me₂] (L–L=S–As, S–P) with HCl affords the monomethyl derivatives [Pd(L–L)Me(Cl)]. In contrast to the Pt analogues, [Pd(L–L)Me₂] and [Pd(L–L)Me(Cl)] are relatively less stable than [Pt(L–L)Me₂] and [Pt(L–L)Me(Cl)].     

Electrochemical Properties and Analytical Applications of Keggin-type Phosphomolybdic Anions in Electrostatically Linked 2-Aminoethanethiol Self-Assembled Monolayers

A composite film containing a heteropolyanion was prepared on a 2-aminoethanethiol (AT) self-assembled monolayer film-modified gold electrode by attaching the Keggin-type phosphomolybdic anion. The surface structures and electrochemical properties of the composite films were characterized by using ATR-FTIR, AC impedance, cyclic voltammetry and chronocoulometry. FTIR studies indicated that there was some electrostatic interaction between Pmo₁₂O₄₂^7– and surface NH₃⁺. Three reversible redox couples were observed in 1.0molL^–1 H₂SO₄ in the potential range of 0–0.7V for the composite film modified electrode, which were attributed to two-electron and two-proton electrochemical processes of PMo₁₂O₄₂^7–. The diffusion coefficient is determined to be 2.04×10^–7cm²s^–1. The composite film shows good catalytic activities for the reduction of nitrite (NO₂^–) in acidic solution and the catalytic mechanisms are described. The modified electrode provides a linear response for NO₂^– in the concentration range of 1.0×10^–4 to 1.0×10^–7molL^–1 by differential pulse adsorptive stripping voltammetry with a correlation coefficient of 0.9965. The detection limit (three times the signal blank/slope) was 2.0×10^–8molL^–1. The modified electrode was used for the determination of NO₂^– in wastewater.     

Applications of pulse radiolysis and flash photolysis to some problems related to the chemistry of cancer therapy

The semireduced form (Adr) of the anti-tumour agent adriamycin is implicated in cardiotoxic side effects. Adr, prepared by reduction with e _aq ^– and CO ₂ ^– , has pK values at 2.9 and 9.2. In the pH range 6–11, Adr is relatively stable, existing in equilibrium with Adr and the hydroquinone, the latter subsequently losing the sugar within 100 ms. The E ₇ ¹ of Adrais –328 mV, so at equilibrium the reaction O ₂ ^– + AdrO₂ + Adr lies well over to the left. The relative yields of O₂(¹g) formed via energy transfer from triplet excited components of haematoporphyrin derivative, the drug used in photodynamic therapy, have been measured by observations of the phosphorescence emission at 1270 nm. The measurements suggest that the most active component, dihaematoporphyrin ether or ester, is comparatively ineffective itself photodynamically, but may serve as a pool for the more effective haematoporphyrin and hydroxyethylvinylporphyrin to act inside the cancer cell. One-electron oxidation of dopa, through N ₃ ^. or photoionization, leads to the melanin precursor dopachrome via dopasemiquinone and dopaquinone. The latter reacts with cysteine to form cysteinyldopa, a marker for malignant melanoma metastasis. N ₃ ^. —initiated oxidation of cysteinyldopa proceeds via a different mechanism involving the corresponding semiquinone, quinone and a quinone-imine which rearranges to a more stable benzothiazole.     

The reactivity of complexed carbocycles,part 9. New cyclononatetraene cobalt complexes(1)

Summary Two new C₅H₅CoC₉H₁₀ cobalt complexes were shown to contain the cyclononatetraene ligand coordinated in a (3–6-)- and in a (1–25-6-) fashion. The former complex (2) rearranges at elevated temperatures to the latter (3) in a novel type of isomerisation. Complex (3) can be protonated with strong acids and hydrogenated at the uncomplexed double bonds. All compounds were characterised by¹³C n.m.r. spectroscopy.     

Homolytic addition of isopropyl alcohol to divinyl ethers of 1,1- and 1,2-diols

The reaction of divinyl ethers of 1,1- and 1,2-diols with isopropyl alcohol in the presence of tert-butyl peroxide gave, in addition to telomers, cyclic adducts (11), to which the 5-methyl-4-(2-hydroxy-2-methylpropyl)-1,3-dioxolane structure (in the case of divinyl ethers of gem-diols) or the 2-methyl-3-(2-hydroxy-2-methylpropyl)-1,4-dioxane structure (in the case of the vic-diols) was assigned.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 298–302, March, 1972.     

Synthesis and products of hydrolysis of 2-methyl-5-(β-arylacrylyl)-2-oxazolines

The condensation of 2-methyl-5-acetyl-2-oxazolines with p-R-substituted benzaldehydes in the presence of bases gave the corresponding 2-methyl-5-(-aryl-acrylyl)-2-oxazolines, the hydrolysis of which with hydrochloric acid leads to hydrochlorides of alkyl-substituted 1-(p-R-styryl)-2-acetoxy-3-aminobutan-1-ones. Treatment of the latter with bases gives 1-(p-R-styryl)-2-hydroxy-3-N-acetyl-2, 3-alkylbutan-1-ones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1025–1027, August, 1982.     

Pseudohalogen compounds of astatine: Synthesis and characterization of At/I/-tricyanomethanide-and At/I/-azide-compounds

Reactions of At//⁺, At^o.H₂O, AtCl ₂ ^– and AtBr₂ with the pseudohalogenides tricyanomethanide and azide are described. Information on the compound formation of astatine with C/CN/ ₃ ^– and N ₃ ^– could be obtained on the basis of electromigration investigations under variation of the conditions /composition of the electrolyte, pH, exchange reactions of ligands/. For the reaction: [At/H₂O/C/CN/₃]+C/CN/ ₃ ^– [At/C/CN/₃/₂]+H₂O at 301 K and u=0.075 mol.l^–1 K₂=/675±25/ [1.mol^–1] and u^o=–/3.50±0.10/×10^–4 [cm².s^–1.V^–1]. According to this astatine/I/-tricyanomethanide is classified between AtI ₂ ^– and At/SCN/ ₂ ^– . First investigations in azid-containing systems confirm the formation of astatine/I/-azide-compounds. Their composition is probably At/N₃/ ₂ ^– . There is no dependence of the ion mobility of astatine/I/-azide in the investigated range on azide concentration which is due to its high stability.     

Synthesis of condensed structures from 3-cyano-2-pyridylacrylic acids

Ammonolysis of the methyl esters of trans--(3-cyano-2-pyridyl)acrylic (I) and trans--(6-methyl-3-cyano-2-pyridyl)acrylic (II) acids gave the amides of these acids. The addition of bromine, diazomethane, and hydrogen to the double bond of cis- and trans-acids I and II is described. Hydrogenation of the methyl esters of trans-acids I and II over Raneynickel at room temperature and atmospheric pressure occurs with intramolecular cyclization to two-ring lactams — 7-oxo-5, 6,8,9-tetrahydropyrid[3,2-c]azepine and 2-methyl-7-oxo-5,6,8,9-tetrahydropyrid[3,2-c]azepine. Under the conditons of acid hydrolysis of acids I and II the elements of water add to the nitrile group with intramolecular cyclization to give, respectively, 3-carboxymethyl-1-oxo-2,3-dihydrofuro [4,3-b]pyridine and 5-methyl-3-carboxymethyl-1-oxo-2,3-dihydrofuro[4,3-b]pyridine, whereas refluxing these acids with aqueous sodium hydroxide gives two-ring lactams — 3-carboxymethyl-1-oxo-2, 3-dihydropyrrolo[4,3-b]pyridine and its 5-methyl homolog. The structures of the compounds were confirmed by the UV, IR, PMR, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 63–69, January, 1978.     

Heterocyclic analogs of pleiadiene

1-Methylperimidine adds phenylsodium and phenyllithium to the C=N bond to give 1-methyl-2-phenyl-2, 3-dihydroperimidines. However, if benzophenone is present in the reaction mixture, a mixture of 1-methyl-2-phenylperimidine and l-methyl-2, 4-diphenylperimidine (when phenylsodium is used) or l-methyl-2-phenyl-4-(-hydroxybenzhydryl)perimidine (when phenyllithium is used) is formed. It is assumed that the formation of products involving substitution in the naphthalene ring is associated with the participation of C₆H₅ and (C₆H₅)₂C-O^– radical particles that are formed on reaction of the phenylmetallic compound with benzophenone.See [1] for communication XXIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 697–701, May, 1976.