Mass spectrometry and structure of ions of heterocyclic compounds activated by collision: Naphthiridines and benzazines

The dissociation and the structure at the isomeric [M — HCN]⁺ and [M — 2HCN]⁺ ions, formed during the fragmentation of naphthiridines and benzazines, were investigated by the collisionally activated dissociation (CAD) method. It was established that the stable [M — HCN]⁺ ions of 1,5- and 1,8-naphthiridines, 1,6-naphthiridine, quinoxaline, and quinazoline have different structures. The [M — 2HCN]⁺ ions can exist in two isomeric forms, one of which is characteristic of naphthiridines and the other of benzazines.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vo. 25, No. 5, pp. 626–629, September–October, 1989.     

Interactions of copper tetra-tert-butylphthalocyanine with nitrogen- and sulfur-containing compounds in solutions

Interactions of ammonia, aliphatic amines, hydrogen sulfide, and sulfur dioxide with copper tetra-tert-butylphthalocyanine (CuPc) in squalane were studied by spectrophotometry and gas liquid chromatography in the CuPc concentration range of 1·10^–3—5·10^–2 mol L^–1. The sorption properties of the CuPc—squalane stationary liquid phases (SLPs) are governed by the physicochemical nature of the CuPc nanoaggregates in solution. The -type nanoaggregates exhibit particularly high activity to hydrogen sulfide; the activities to primary and secondary amines are also high.     

UV spectra of carbonyl-contaiming furan compounds

The optical absorption maxima in the UV spectra of furan aldehydes, ketones, acids and their derivatives — acid chlorides, anhydrides, esters, and diacyl peroxides ^– can be arranged in an order similar to the order of reactivities of the carbonyl groups. The effect of a solvent on the position of _max was examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 590–594, May, 1973.     

Synthesis,crystal structure and magnetic properties of a two-dimensional mixed-valence assembly [Fe(salen)]2[Fe(CN)5NO]

A cyanide-bridged Fe^III–Fe^II mixed-valence assembly, [Fe^III(salen)]₂[Fe^II(CN)₅NO] [salen = N,N-ethylenebis(salicylideneiminato)dianion], prepared by slow diffusion of an aqueous solution of Na₂[Fe(CN)₅NO] · 2H₂O and a MeOH solution of [Fe(salen)NO₃] in an H tube, has been characterized by X-ray structure analysis, i.r. spectra and magnetic measurements. The product assumes a two-dimensional network structure consisting of pillow-like octanuclear [—Fe^II—CN—Fe^III—NC—]₄ units with dimensions: Fe^II—C = 1.942(7) Å, C—N = 1.139(9) Å, Fe^III—N = 2.173(6) Å, Fe^II—C—N = 178.0(6)°, Fe^III—N—C = 163.4(6)°. The Fe^II—N—O bond angle is linear (180.0°). The variable temperature magnetic susceptibility, measured in the 4.8–300 K range, indicates the presence of a weak intralayer antiferromagnetic interaction and gives an Fe^III–Fe^III exchange integral of –0.033 cm^–1.     

The N—H and O—H bond dissociation energies in 4-hydroxydiphenylamine and its phenoxyl and aminyl radicals

The N—H and O—H bond dissociation energies in 4-hydroxydiphenylamine Ph—NH—C₆H₄—OH (D _NH= 353.4, D _OH=339.3 kJ mol^–1) and its semiquinone radicals D _NH(Ph—NH—C₆H₄—O^·) = 273.6, D _OH(Ph—N^·—C₆H₄—OH) = 259.5 kJ mol^–1 were first estimated using the parabolic model and experimental data (rate constants) on two elementary reactions with participation of N-phenyl-1,4-benzoquinonemonoimine (2). One of the reactions, namely, that of 2 with aromatic amines, was studied in this work using a specially developed method.     

Studies on pyran,its analogs,and related compounds

The action of guanidine on esters of chromone-2-carboxylic acids leads to the opening of the pyrone ring and to the formation of hydantoin derivatives — 2-imino-5-(2-hydroxybenzoylmethylene)tetrahydroimidazol-4-ones — in addition to other reaction products.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 7, pp. 874–875, July, 1970.     

Investigations in the field of perinone compounds

The directed synthesis of structurally isomeric nitronaphthaloperinones — 10-nitro-and 11-nitro-14H-benz[4,5]isoquinolino[2,1-a]perinidin-14-ones — has been effected.For Communication I, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 6, pp. 842–843, June, 1970.     

Conformations of triplet carbonyl compounds: Formaldehyde, acetaldehyde, propionaldehyde and acetone

A conformational study on the lowest triplet states of formaldehyde, acetaldehyde, propionaldehyde and acetone has been done using a minimal basis set, within the unrestricted Hartree—Fock framework.For the C₃H₆O species, the energy hypersurfaces (E θ₁, θ₂, θ₃) were generated, where energy is a function of the methyl rotations (θ₁, θ₂) and C---O out-of-plane bending for acetone, and a function of methyl rotation (θ₁), C₂H₅---C rotation (θ₂) and CHO out-of-plane deformation (θ₃) for propionaldehyde.The analysis of the hypersurface equations revealed the location and relative energies of the critical points (minima, first and second order saddle points as well as maxima): the barriers to inversion at the carbonyl group were 2.7 kcal mol⁻¹ for acetone and 4.2 kcal mol⁻¹ for propionaldehyde. Partial geometry optimization reduced these barriers to 2.5 and 2.4 kcal mol⁻¹ respectively.For comparison, both the pyramidal minimum and planar saddle point for the inversion of triplet formaldehyde and acetaldehyde were totally optimized; the resultant barriers were 2.0 kcal mol⁻¹ and 2.3 kcal mol⁻¹, respectively. The barrier to rotation about the bond to the α-carbon was 1.1 kcal mol⁻¹ for pyramidal acetone, 1.0 for acetaldehyde and ranged from 0.8 to 1.8 kcal mol⁻¹ for the various propionaldehyde conformers.     

Sulfurization of polymers. 6. Poly(vinylene polysulfide), poly(thienothiophene), and related structures from polyacetylene and elemental sulfur

Polyacetylene obtained by the dehydrochlorination of polyvinyl chloride in the NaOH—DMSO system undergoes sulfurization with elemental sulfur at 120—300 °C to liberate hydrogen sulfide and to form electroconducting (0.7·10^–12—5.8·10^–15Sm nm^–1) and paramagnetic (1.5·10¹⁷—1.7·10¹⁹sp g^–1, g = 2.0035—2.0045, H= 0.44—0.66 mT) dark powders with a metallic luster. Their IR spectra and comparison with the samples of sulfurized polyethylene show that sulfurized polyacetylene contains poly(vinylene polysulfide), poly(thienothiophene), and related structures. The polymers afford the cathode discharge capacity of lithium batteries up to 950 mA h g^–1(in the first cycle) and stable cycling at a level of 500—300 mA h g^–1(25 cycles).     

New heteroorganic betaines containing the (+)E15—C—E14—X(–) and (+)E15—C—E14(–) structural fragments (E15 = P,As; E14 = Si,Ge, Sn; X = C,S, O,NR)

The review surveys the data on the reactions of phosphorus and arsenic ylides with compounds containing E=X bonds (E = C, Si, Ge, or Sn; X = C or S), cyclic oligomers (R₂ES)_n (n = 2 or 3), and heavier analogs of carbenes. These reactions give rise to two new classes of heteroorganic betaines containing the ⁽⁺⁾E¹⁵—C—E¹⁴—X^(–) (I) and ⁽⁺⁾E¹⁵—C—E^14(–) (II) (E¹⁵ = P or As; E¹⁴ = Si, Ge, or Sn; X = C or S) structural fragments. Procedures for the synthesis of these compounds, their reactivities, the X-ray diffraction structures, and the electronic structures established by high-level quantum-chemical calculations are considered in detail. The carbon analogs of betaines of type I, viz., compounds bearing the ⁽⁺⁾P—C—C—X^(–) fragment (III), are also discussed. The latter were long considered as possible intermediates in the reactions of compounds containing the polar C=X bond (X = C, O, S, NR, etc.) with phosphorus ylides (classical Wittig and Corey—Chaykovsky reactions and related processes).     

Reaction of superacid HGeCl3 with aromatic compounds. 8. Formation of long-lived carbocations stabilized by the GeCl3 anion in the reaction with 1,3-dialkoxybenzenes; crystal structure of 1,1,3,5-tetrakis(trichlorogermyl)-3-ethoxycyclohexane

Cyclohexenyl cations that are long-lived at –50°C are stabilized by the GeCl₃ ^– anion and are detected and characterized spectrally in reactions of HGeCl₃ with 1,3-dialkoxybenzenes. Further reactions of the cyclohexenyl cations are studied. The x-ray crystal and molecular structure of the final reaction product of HGeCl₃ with 1,3-diethoxybenzene — 1,1,3,5-tetrakis(trichlorogermyl)-3-ethoxycyclohexane — is solved.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 895–900, April, 1990.For previous communication, see [1].     

Thermal transformations in systems based on zeolites Y,X, and A containing zinc and sodium nitrates

Thermal transformations in systems formed by interaction of Zn and Na nitrates with Y, X, and A zeolites were studied by TG—DTA technique. Temperature regions of existence of adsorbed water, water of crystallization, and decomposition of NO₃ ^– anion were determined. These intervals depend on the composition, structure, method of preparation, and pre-treatment conditions of zeolite systems. The extent of NO₃ ^– decomposition depends not only on the zinc and sodium content but also on the presence of ammonia involved in NO₃ ^– reduction. The zeolite matrix strongly stabilizes the occluded NO₃ ^– anions. A portion of zinc oxide formed by zinc nitrate decomposition is probably localized inside the zeolite cavities as the [Zn—O—(ZnO) _n —Zn]²⁺ particles. The latter compensate charges of the isolated [AlO₄]^– tetrahedra.     

Heteroorganic betaines. 7. Synthesis and structure of a germanium-containing organophosphorus betaine Et3P+—CHMe—GeMe2—S–

Germanium-containing organophosphorus betaine Et₃P⁺—CHMe—GeMe₂—S^– was synthesized by the reaction of hexamethylcyclotrigermatrithiane with Et₃P=CHMe. The structure of the betaine was established by X-ray diffraction analysis and multinuclear NMR spectroscopy. In the crystal, the P⁺—C—Ge—S^– main chain of the molecule adopts a folded cis-gauche conformation due to strong Coulomb interactions between the anionic and cationic centers. The equilibrium geometry of the isolated molecule was calculated within the framework of the density functional theory (the PBE functional, the TZ2P basis set). The calculated geometric characteristics are in qualitative agreement with the X-ray data. The structure of the betaine is compared with the structure of its silicon-containing analog studied previously.     

210Pb and 137Cs geochronologies in the Cananeia-Iguape Estuary (Săo Paulo, Brazil)

Sediment cores were collected at the Cananeia-Iguape Estuary and thelevels of ²¹⁰Pb, ²²⁶Ra and ¹³⁷Cs were measuredby gamma-ray spectrometry. The total ²¹⁰Pb levels in sedimentsvaried from 13.5 to 122.5 Bq . kg ^—1 , for ²²⁶Raranged from 2.4 to 28 Bq . kg ^—1 and for ¹³⁷Csfrom 0.28 to 6.1 Bq . kg ^—1 . Sedimentation rates were calculatedfrom the slope of the excess ²¹⁰Pb profile in the core. The valuesobtained varied from 5 to 10 mm . y^—1 , depending on thesediment deposition inputs in the local of sampling.     

Magnetische und röntgenographische Untersuchungen an der Legierungsreihe SrAg5—SrPd5

Zusammenfassung Wider Erwarten bilden die isotypen Phasen SrAg₅ und SrPd₅ (CaCu₅-Typ) keine durchlaufende Mischkristallreihe. Zwischen 40% SrPd₅ und 90% SrPd₅ besitzen die Mischkristalle eine andere Struktur, die mit der CaCu₅-Struktur jedoch eng verwandt ist. Von Feinheiten abgesehen, zeigt die magnetische Suszeptibilität einen ähnlichen Gang wie die der Ag—Pd-Mischkristalle. Der Diamagnetismus von SrAg₅ (—10,9·10^—6 cm³/gAtom) nimmt bei Ersatz von Ag durch Pd linear zu und erreicht bei 38% SrPd₅ einen Grenzwert von —22,4·10^—6 cm³/gAtom. In diesen Legierungen wird Palladium mit vollaufgefülltem 4d-Band nullwertig eingebaut. SrPd₅ ist mit 63,1·10^—6 cm³/gAtom paramagnetisch. Durch Zulegieren von Silber fällt die Suszeptibilität steil ab, woraus zu schließen ist, daß auch hier, wie in den EdeImetall-Mischkristallen Ag—Pd, die Lücken im 4d-Band des Palladiums stetig aufgefüllt werden.

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Magnetic and x-ray cristallographic studies in the Alloy series SrAg₅—SrPd₅

Contrary to expectation the isotypic phases SrAg₅ and SrPd₅ (CaCu₅-type) do not form a continuous mixed crystal series. In the range 40% SrPd₅ and 90% SrPd₅ the mixed crystals have a different structure, which is however closely related to the CaCu₅ structure. Neglecting fine detail, the magnetic susceptibility shows a trend similar to that of the Ag—Pd mixed crystals. The diamagnetism of SrAg₅ (—10.9·10^—6 cm³/g-atom) increases linearly on replacing Ag by Pd, attaining a limiting value of —22.4·10^—6 cm³/g-atom at 38% SrPd₅. In these alloys palladium is incorporated in a nonvalent state with completely filled 4d band. SrPd₅, with 63.1·10^—6 cm³/g-atom, is paramagnetic. Alloying of silver causes a steep decline in susceptibility, leading to the conclusion that here as in the precious metal mixed crystals Ag—Pd the gaps in the palladium 4d band are continuously filled.

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Mit 7 Abbildungen

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Herrn Prof. Dr.H. Nowotny gewidmet.     

Diisophorone and related compounds. Part 1413C-nuclear magnetic resonance spectra of diisophorone carboxylic acids

The¹³C-nmr spectra of a group of diisophorone carboxylic acids have been determined and fully assigned. The spectral data confirm, in some cases decisively, the formulation of members of this series of compounds. In the light of the spectral information, the stereochemistry of the C(4)-C(5)-region of the diisophorone ring-system is discussed, with special reference to the configuration of the 4-substituents.

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Diisophorone und verwandte Verbindungen, 14. Mitt.:¹³C-NMR Spektren von Diisophoron-carbonsäuren

Zusammenfassung Die¹³C-Kernresonanzspektren einer Anzahl von Diisophoron-carbonsäuren wurden aufgenommen und die Signale den Atomen des Kohlenstoffgerüstes zugeordnet. Die so erhaltenen Beziehungen ermöglichen ihrerseits die Bestätigung — und in gewissen Fällen die entscheidende Sicherung — der Struktur weiterer Beispiele dieser Verbindungsreihe. Die sterische Anordnung des C(4)-C(5)-Bereiches im Diisophoron-Ring-System, insbesondere die Konfiguration von 4-Substituenten, wird an Hand der spektroskopischen Ergebnisse erörtert.

     

Etude de la structure du cortège électronique par la méthode des états de valence

Résumé La méthode des états de valence décrite précédemment est appliquée à l'état fondamental de l'atome neutre de Carbone. On obtient les valeurs suivantes des énergies associées aux termes spectraux ³ P,¹ D et ¹ S: — 75,47900, — 75,36826 et — 75,30856 en unités Rydberg. L'erreur relative reste inférieure à 4 pour mille.

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The method of valence states previously described, is applied to the ground configuration of the neutral carbon atom. The term energies obtained are (in Rydbergs) ³ P: — 75.47900, ¹ D: — 75.36826, and ¹ S: — 75.30856, with errors below 4%.

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Zusammenfassung Die früher beschriebene Methode der Valenzzustände wird auf die Grundkonfiguration des neutralen C-Atoms angewandt. Man erhält folgende Termenergien (in Rydberg): ³ P: — 75,47900, ¹ D: — 75,36826 und ¹ S: — 75,30856, mit Fehlern unter 4%.

     

Successive projections algorithm improving the multivariate simultaneous direct spectrophotometric determination of five phenolic compounds in sea water

This paper proposes an analytical method to determine directly and simultaneously five phenolic compounds (4-nitrophenol, 2-nitrophenol, phenol, 2,4,6-trichlorophenol and 4-chlorophenol) in sea water (Ria de Bahía Blanca, Argentine). The advantages of this method is that only requires spectrophotometric measurements (separation steps and derivatization reagents are avoided) and chemometric modelling (PLS and MLR–SPA).The statistical comparison between PLS — a well established multivariate method — and MLR–SPA — a recently presented chemometric modelling — demonstrated better analytical performance for the later one. This fact is indicative of the potentiality of MLR–SPA for solving complex analytical problems.     

Inorganic and organometallic chemistry of PtIII complexes having a delocalized PtIII—PtIII bond

Amidate-bridged dinuclear Pt^III complexes having a Pt^III—Pt^III bond react with ketones and alkenes. In the reaction with alkenes in water, 1,2-diols are obtained. In the reactions with conjugated dienes, stereospecific 1,4-diols are formed selectively. A kinetic study revealed that at each intermediate step of the reaction with alkenes the electronic state of the Pt—Pt bond changes between Pt^III—Pt^III and Pt^II—Pt^IV and stabilizes the reaction intermediates.     

Mass spectrometric study of 4-azafluorenes

The dissociative ionization of 4-azafluorene and its methyl and phenyl derivatives was investigated. The relative intensity of the [M — CH₃]⁺ ion peak depends on the position of the CH₃ group in the 4-azafluorene ring. It was established that the loss of an RCN particle (R=H, CH₃, and C₆H₅) for unsubstituted 4-azafluorene takes place from the M⁺ and [M — H]⁺ ion, exclusively from the [M — H]⁺ ion for the methyl-substituted compounds, and from the [M — H]⁺ and [H — 2H]⁺ fragments for the phenyl-substituted derivatives. Randomization of the deuterium ions in the 9,9-d₂-4-azafluorene molecular ion was observed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 246–250, February, 1978.