Molecular Structure of 1,3,5-Tris (Trimethylstannyl) Benzene: An Electron Diffraction Study

The molecular structure of 1,3,5-tris (trimethylstannyl) benzene has been determined by gas-phase electron diffraction. The C — C bond length is in good agreement with that in benzene. In agreement with the somewhat electron-releasing character of the substituents, the endocyclic bond angles at the substituents are somewhat smaller than 120°. The mean value of Sn — C bond lengths is greater than that in tetraphenyltin and tetramethyltin. The SnMe₃ groups appear freely rotating around the C_aryl — Sn bonds. The following bond lengths (r _g) and bond angles were determined: (Sn — C)_mean 2.150 ± 0.007 Å, C — C 1.399 ± 0.005 Å, (C — H)_mean 1.105 ± 0.006 Å, < C — C(Sn) — C 117.7 ± 1.7º, < C_aryl — Sn — C_methyl 106.7 ± 0.7º < Sn — C — H 111.5 ± 0.9º.     

Ionization constants of a number of alkaloids used in medicine

The pK_a values of a number of alkaloids in water or in aqueous ethanol have been measured by the potentiometric titration method: nuphleine — 4.59, 6.98; brevicolline — 5.17, 8.02; chelidonine — 6.40; sanguinarine — 7.32; chelerythrine — 7.53; stepharine — 8.48; d-pseudoephedrine — 9.49. For nuphleine and brevicolline, each of which has two nitrogen atoms capable of protonation, assignments have been made of pK_a values to the corresponding atoms on the basis of the results of UV spectroscopy.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 337–341, May–June, 1984.     

Development of a New Alkali Resistant Coating

The effect of different new sol-gel BaO—TiO₂—SiO₂ and CaO—BaO—TiO₂—SiO₂ coatings on long-term durability of glass fiber reinforced cement (GRC) was examined. Flexural strength of GRC was measured after curing for 7 to 150 days. Significant improvement was observed for coated GRC in this study and discussed in terms of the hydrate formation at interface. Concerned with the alkali resistance, CaO—BaO—TiO₂—SiO₂ coating was more effective than BaO—TiO₂—SiO₂ coating. In special, the 10CaO—10BaO—60TiO₂—20SiO₂ coating, prepared by sol-gel method, was recommended for the highest flexural strength of GRC and least corrosion at surface of E-glass fiber.     

Synthesis of regular polypeptides including L-lysine and glycine

Conclusions The synthesis of two regular polypeptides with the composition (—Gly—L-Lys—Gly)_n and (—L-Lys—L-Lys—Gly—)_n with molecular weights of 250 and 5000 has been effected.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 4, pp. 459–462, 1970The bulk of this work was carried out in the Protein Chemistry Laboratory of the Institute of Organic Chemistry, AS USSR.     

Die Verbindungen der St?rke und des Dextrins mit freiem Jod

Ohne ZusammenfassungVergl. hierzu R. Fresenius, Ann. d. Chem. u. Pharm.102, 184. — Diese Zeitschrift1, 84 u. 465. — Pohl, diese Zeitschrift1, 84. — Personne und Schönbein ebenda1, 369. — Béchamp ebenda1, 465. — Biot u. Persoz und Scheibler ebenda10, 373. — L. Bondonneau ebenda16, 114. — Musculus u. Gruber ebenda18, 109. — O'Sullivan und Brown u. Heron ebenda19, 213.     

A New Predictive Equation for the Depression in Freezing Points of Multicomponent Aqueous Solutions Conforming to the Linear Isopiestic Relation

The linear isopiestic relation has been used together with a well-known thermodynamic equation to establish a new predictive equation for freezing point depression. This equation can provide predictions for multicomponent solutions conforming to the linear isopiestic relation using only information on the corresponding binary subsystems. The predictive capability of the equation has been tested by comparing with the experimental data at 25°C reported in the literature and particularly those of Pathwardhan and Kumar. The systems used are NaCl—MgCl₂—H₂O, NaCl—BaCl₂—H₂O, NaCl—CaCl₂—H₂O, LiCl—NaCl—H₂O, LiCl—KCl—H₂O, LiCl—CsCl—H₂O, NaCl—KCl—H₂O, and NaBr—KBr—H₂O. The predictions of the two equations agree well with the experimental data although our new equation is, in general, better.     

Crystalline and molecular structures of the alkaloid delcosine

The molecular and crystalline structures of the diterpene alkaloid delcosine (iliensine) have been investigated by x-ray structural analysis. It has been confirmed that the OH group in ring A is located at C(1) and has the orientation. The rings in the molecule have the following conformations: A, B, and D — boat; C and F — envelope; E — chain. The ring linkages are: A/B — trans; A/E — cis; B/C — cis; B/D — cis; B/F — cis. The conformations and linkages of the rings are identical with those observed in lycoctonine.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 754–758, November–December, 1983.     

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.     

Das Dreistoffsystem: Molybdän—Silizium—Kohlenstoff

Neubearbeitung des Randsystems Mo–C. — Strukturermittlung an MoC. — Thermische Untersuchung an dem Paar Si–C. — Aufstellung des Dreistoffsystems Mo–Si–C durch röntgenographische sowie Schmelzpunktsmessungen bzw. mikroskopische Beobachtungen. — Kristallstruktur und Eigenschaften einer neuen ternären Phase.

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Mit 10 Abbildungen.     

Phytoecdysteroids of plants of the genus Melandrium I. Polypodin B 22-acetate from Melandrium turkestanicum

Known ecdysteroids — ecdysterone, ecdysterone 22-acetate, polypodin B, integristerone A, and sileneosides A and D — and a new phytoecdysteroid — polypodin B 22-acetate — have been found in the epigeal parts of the plantMelandrium turkestanicum (Rg1.) Vved. (family Caryophyllaceae).Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–483, July–August, 1990.     

Physicochemical properties and substrate specificity of protease C from dormant cotton seeds

The substrate specificity of a proteolytic enzyme — protease C — isolated from cotton seeds has been studied. The activity of protease C is suppressed completely under the action of diisopropyl phosphorofluoridate. Protein inhibitors — duck ovomucoid, soybean inhibitor, and also TPCK — suppressed the activity of protease C to different degrees. On the basis of results obtained in the hydrolysis of the cottonseed reserve proteins, 7S and 11S globulins, and the B chain of insulin, protease C has been assigned to the serine group of endopeptidases. The optimum conditions — pH, time, and temperature — at which protease C exhibits its maximum activity has been determined.Institute of Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 744–746, September–October, 1988.     

Thermoanalytische Untersuchungen psychotroper Substanzen vom Typ der Abwandlungsprodukte des Phenothiaztns und der Butyrophenone auf Isomorphie und Polymorphie. II

Zusammenfassung Aus der Gruppe der Dibenzoazepinderivate wurden die Hydrochloride von Clomipramin, Imipramin und Desipramin miteinander kombiniert und aus der Gruppe der Dibenzocykloheptadiene bzw.-triene die Hydrochloride von Amitriptylin, Nortriptylin, Noxiptilin und Protriptylin.Bei fünf der untersuchten binären Systeme liegt Mischkristallbildung aufgrund von Isomorphiebeziehungen mit instabilen Modifikationen vor: Imipraminhydrochlorid — Clomipraminhydrochlorid, Imipraminhydrochlorid — Desipraminhydrochlorid, Clomipraminhydrochlorid — Desipraminhydrochlorid, Nortriptylinhydrochlorid — Protriptylinhydrochlorid und Noxiptilinhydrochlorid-Amitriptylinhydrochlorid. Das Substanzpaar Protriptylinhydrochlorid — Noxiptilinhydrochlorid bildet eine Molekülverbindung im Verhältnis 11. In drei Fällen werden einfache Eutektika gebildet.

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Thermoanalytical investigations of psychotropic substances derived from phenothiazine and butyrophenones for isomorphism and polymorphism. II

Summary From the group of dibenzoazepine derivatives, the hydrochlorides of clomipramine, imipramine and desipramine were combined with each other and from the group of dibenzocycloheptadienes or -trienes the hydrochlorides of amitriptyline, nortriptyline, noxiptiline and protryptiline. In five of the binary systems investigated, there is formation of mixed crystals due to isomorphism with unstable modifications: imipramine hydrochloride — clomipramine hydrochloride, imipramine hydrochloride — desipramine hydrochloride, clomipramine hydrochloride 3- desipramine hydrochloride, nortriptyline hydrochloride — protriptyline hydrochloride and noxiptiline hydrochloride — amitriptyline hydrochloride. The substance pair protriptyline hydrochloride — noxiptiline hydrochloride forms a molecular compound in the ratio 11. In three cases, simple eutectics are formed.

     

The seed oil of Catalpa. I

Summary 1. The fatty-acid compositions of the seed oils of catalpas cultivated in the Soviet Union have been studied.2. The oil content of the seeds is 21.2–36.7%, the refractive index 1.4905–1.5400, and the iodine number 184.8–201.7.3. The following fatty acids have been found in catalpa oil (%): palmitic — 1.3–4.3; stearic — 1.1–2.5; heneicosanoic — 0.5–5.2; oleic — 5.5–9.8; linoleic — 39.6–50.3; linolenic — 0.4–1.8; and eleostearic — 32.8–46.2.4. The most accurate results for characterizing the degree of unsaturation of the fatty acids of the catalpa seed oils are given by Woburn's method of determining iodine numbers. The iodine numbers obtained experimentally agree with those calculated and consequently the addition of halogen to the system of double bonds takes place at all the double bonds.5. The degree of unsaturation of the fatty acids of catalpa oil characterized by the iodine numbers and refractive indices increases in the sequence of species southern, northern, teas, Chinese and has a tendency to rise on passing to more northerly zones, which is one more piece of evidence confirming the correctness of S. L. Ivanov's climatic theory of the structure of fats.Kalinin Polytechnic Institute. Moscow Branch of the All-Union Scientific-Research Institute of Fats. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 331–337, May–June, 1977.     

R?ntgenstrukturanalyse als unentbehrliches Hilfsmittel bei der absoluten Konfigurationszuordnung einiger Iridoidglucoside sowie daraus synthetisierter 12-epi-Prostaglandine

Ohne Zusammenfassung

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X-ray-structure-analysis as indispensable tool in structure elucidation of some iridoidglucosides as well as 12-epi-prostaglandines derived from them

Abkürzungen C(OH)₄ -d-Glucopyranosyl - Ac CH₃—CO - Ts p-CH₃—C₆H₄—SO₂ - Cin C₆H₅—CH=CH—CO - HCin C₆H₅—CH₂—CH₂—CO—O - DME Dimethoxyethan     

Saturated heterocycles, 75. Preparation of tetracyclic thiophene derivatives with bridgehead nitrogen. Synthesis of polymethylenethieno[2,3—d]dihydropyrrolo-, tetrahydropyrido- and tetrahydroazepino[1,2—a]pyrimidin-4-ones and -4-thiones

The following tetracyclic ring systems and their derivatives have been synthesized for pharmacological investigations: Trimethylenethieno[2,3—d]dihydropyrrolo[1,2—a]pyrimidin-4-one and -4-thione (1 a, 5 a); Tetramethylenethieno[2,3—d]dihydropyrrolo[1,2—a]pyrimidin-4-one and -4-thione (1 b, 1 j, 5 b); Pentamethylenethieno[2,3—d]dihydropyrrolo[1,2—a]pyrimidin-4-one and-4-thione (1 c, 5 c); Trimethylenethieno[2,3—d]tetrahydropyrido[1,2—a]pyrimidin-4-one and -4-thione (1 d, 5 d); Tetramethylenethieno[2,3—d]tetrahydropyrido[1,2,—a]pyrimidin-4-one and -4-thione (1 e, 5 e); Pentamethylenethieno[2,3—d]tetrahydropyrido[1,2—a]pyrimidin-4-one and -4-thione (1 f, 5 f); Trimethylenethieno[2,3—d]tetrahydroazepino[1,2—a]pyrimidin-4-one and -4-thione (1 g, 5 g); Tetramethylenethieno[2,3—d]tetrahydroazepino[1,2—a]pyrimidin-4-on and -4-thione (1 h, 5 h); Pentamethylenethieno[2,3—d]tetrahydroazepino[1,2—a]pyrimidin-4-one and -4-thione (1 i, 5 i); Tentamethylenethieno[2,3—d]tetrahydroazepino[1,2—a]pyrimidin-4-one (7 b); Pentamethylenethieno-[2,3—d]tetrahydropyrido[1,2—a]pyrimidin-4-one (7 c).Compounds1 a–i were synthesized from 2-amino-3-ethoxycarbonyl-4,5-polymethylenethiophene2 a–c with the corresponding lactim ethers (3 a–c) in chlorobenzene in the presence of polyphosphoric acid (PPA). Compounds7 b and7 c were obtained in the reaction of -amino acid esters2 b and2 c with 2-bromopyridine (6). The thione derivatives (5 a–i) were prepared from compounds1 a–i with phosphorus(V) sulphide.Part 74:Szabó J, Fodor L, Szcs E, Bernáth G, Sohár P (1984) Pharmazie 39: 347.     

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).     

Synthesis and spectroscopic properties of soluble aza analogs of phthalocyanine and naphthalocyanine

The syntheses of aryl-substituted octaaza analogs of phthalocyanine — tetra-2,3-(4,5-diphenylpyrazino)porphyrazin and its vanadyl complex — and also of the vanadyl complex of tetra-2,3-(4-phenylquinolino)porphyrazin — a tetraaza analog of naphthalocyanine — are described. A modified singlestage method for the synthesis of the previously reported tetra-2,3-(5-tert-butylpyrazino)porphyrazin is put forward. The electronic absorption spectra of the compounds synthesized have been studied in organic solvents and acid media — in sulfuric acid solution and in organic solvents with the addition of phenol or trichloroacetic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 58–63, January, 1993.     

On the Existence and Hydrolytic Stability of Titanosiloxane Bonds in the System: Glycidoxypropyltrimethoxysilane-Water-Titaniumtetraethoxide

Heterometal materials based on glycidoxypropyltrialkoxysilane and titaniumalkoxide are used for optical applications and require a high homogeneity on the molecular level. The presence of heterometal titanosiloxanes, their distribution and hydrolytic stability should influence the homogeneity of these materials. 29Si and 17O NMR spectroscopy has been used to investigate sols with molar ratios Si : Ti = 1 and H2O : OR (H) = 0.5 – 2.0 and their gels after heat treatment at 130°C. The presence of Si—O—Ti bonds in sols with a low water content (H < 0.2) and in the corresponding gels was identified by the high-field shift of the 29Si NMR signals of T1 and T2 units of up to 2–3 ppm compared to corresponding signals of homo-condensed Si—O—Si bonds. The existence of Si—O—Ti bonds in the sols is supported by 17O NMR spectra which show a characteristic signal around 340 ppm. A cleavage of the Si—O—Ti bonds occurs with increasing water/OR ratio in the sols. The cleavage of the heterometal bonds and the building up of homo-condensed species leads to a separation into areas with predominantly Ti—O—Ti and Si—O—Si bonds resulting in a decreased molecular homogeneity of the materials.     

The structures of tenuferin,tenuferinin, and tenuferidin

Summary Three new substances — tenuferin, tenuferinin, and tenuferidin — have been isolated from the roots ofFerula tenuisecta Eug. Kor. It has been shown that they are esters of an undescribed sesquiterpene alcohol — 8,10-dihydroxy-3,4-epoxyguaiane — and isovanillic, vanillic, and p-hydroxybenzoic acids, respectively.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodynkh Soedinenii, No. 1, pp. 70–75, January–February, 1978.