Triterpene glycosides and their genins fromThalictrum foetidum. V. Structure of cyclofoetoside B

A new glycoside (cyclofoetoside B) (I) has been isolated from the epigeal part of the plantThalictrum foetidum L. (Ranunculaceae). On the basis of chemical transformations and with the aid of physicochemical characteristics it has been established that cyclofoetoside B is 24S-cycloartane-3, 16, 24, 25, 29-pentaol 3-O--L-arabinopyranoside 16-O-[O--L-rhamnopyranoside-(1 6)--D-glucopyranoside], C₄₇-H₈₀O₁₇, mp 194–197°C (methanol); [] _D ²⁴ +15.7 ± 2° (c 0.88; pyridine). The enzymatic hydrolysis of (I) has yielded cyclofoetigenin B (III), 24S-cycloartane-3,16,24,25,29-pentaol 16-O--D-glucopyranoside, (IV), C₃₆H₆₂O₁₀, mp 223–225°C (acetone), [] _D ²⁴ +37 ± 2° (c 0.97; methanol) and 24S-cycloartane-3,16,24,25,29-pentaol 16-O-[O--L-rhamnopyranosyl-(1 6)--D-glucopyranoside, C₄₂H₇₂O₁₄, mp 229–231°C (methanol), [] _D ³⁰ +41 ± 2° (c 0.7; methanol). Details of the IR and¹H and¹³C NMR spectra of the compounds are given.Irkutsk Institute of Organic Chemistry, Academy of Sciences of the USSR. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Trashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 341–345, May–June, 1986.     

The phenomenon of conglomerate crystallization. XX. Spontaneous resolution in coordination compounds. XVIII.

The title compound, [cis-Co(en)₂(NO₂)₂](NO₂) (1), crystallizes in the polar, nonenantiomorphic, monoclinic space group, Cc, with lattice constants:a=9.198(2) Å,b=12.444(2),c=9.963(3), and=96.76(2)°;V=1132.39 ų andd(calc;Z=4) =1.860 g cm^–3. Thus, with NO_2– as the counteranion, [cis-Co(en)₂(NO₂)₂] crystallizes in a heterochiral lattice containing racemic pairs of cations. A total of 2699 data were collected over the range of 4°270°; of these, 1859 (independent and withI3(I)) were used in the structural analysis. Data were corrected for absorption (=15.465 cm^–1) and the relative transmission coefficients ranged from 0.9934 to 0.7112. Refinement was carried out for both lattice polarities and the finalR(F) andR _w (F) residuals were, respectively, 0.0242 and 0.0202 for (–––) and 0.0264 and 0.0243 for (+++). Thus, the former was selected as correct for our specimen.Unlike all previous X-ray diffraction studies of the structural properties of the cation [cis-Co(en)₂(NO₂)₂]⁺, which are found to have a pair of oppositely configured en rings [i.e., () or ()], we find that in1 the cations are in the lowest energy conformation and configuration; i.e., () or (). We attribute this change in configuration to the formation of strong interionic hydrogen bonds between nitrite anion oxygens and the axial—NH₂ hydrogens, which markedly weaken the intermolecular and intramolecular hydrogen bonds between ligand—NO₂ oxygens and the hydrogens of those same amine moieties. Thus, the nitrite anions behave exactly as nitrate anions, except that the hydrogen bonds found here are stronger than those formed by the latter. This is as expected since the negative charge is delocalized over two, instead of three, oxygens.     

Unicyclic Graphs with Minimal Energy

If G is a graph and ₁,₂,..., _n are its eigenvalues, then the energy of G is defined as E(G)=|₁|+|₂|++| _n |. Let S _n ³ be the graph obtained from the star graph with n vertices by adding an edge. In this paper we prove that S _n ³ is the unique minimal energy graph among all unicyclic graphs with n vertices (n6).     

Elastizitätsmodul und Dichte von kaltverstrecktem und druckbehandeltem Polyäthylen

Zusammenfassung Proben aus Polyäthylen hoher Dichte wurden bei Raumtemperatur mit verschiedenen Geschwindigkeitenv _ver auf einer Zugprüfmaschine verstreckt. Beiv _ver 10 mm/min beobachtet man eine fast isotherm verlaufende inhomogene Deformation, die zu Verstreckungsgraden=8–13 und mittleren Dichten = 0.80 g/cm³ in den verstreckten Probenbereichen führt. Die bei höherenv _ver bis zu 50 mm/min eintretende adiabatische Erwähnung ergibt höhere Verstreckungsgrade=13–18 und geringere Dichten = 0.64 g/cm³. Es existiert kein natürlicher Verstreckungsgrad. Der Dichteabfall mit zunehmendem kann durch eine Gerade repräsentiert werden; der ElastizitätsmodulE ergibt eine mit zunehmende Kurve.Nach einer Druckbehandlung der Proben mit 5600 bar bei Raumtemperatur erreichte ihre Dichte fast wieder den Anfangswert vor der Verstreckung, wobei keine Abhängigkeit von oder anderen Parametern zeigte. Der ModulE hatte zugenommen, aber nicht proportional zur Dichte. Der Vergleich von undE verstreckter Proben vor und nach der Druckbehandlung weist auf den Netzwerkcharakter von kaltverstrecktem Polyäthylen hin.Herrn Prof. Dr. K. Ueberreiter zum 70. Geburtstag gewidmet.     

X-ray diffraction (powder), e.s.r. and other spectral studies oftris[methylenebis(diphenylphosphine oxide)]iron(III) perchlorate

Summary Bifunctional methylenebis(diphenylphosphine oxide) (mdpo) on reaction with iron(III) perchlorate forms the complex, [Fe(mdpo)₃](ClO₄)₃ · H₂O. This has been characterized through elemental analysis, i.r., far-i.r., u.v. and visible spectroscopy and by x-ray diffraction, magnetic moment, molar conductance and e.s.r. data. The e.s.r. spectrum consists of five lines with transitions from: ¦–5/2¦–3/2¦–3/2¦–1/2, ¦–1/2¦+1/2¦+1/2¦+3/2 and ¦+3/2¦+5/2 centred at a g-value of 2.00. On the basis of these studies, a chelated octahedral structure has been assigned to the cation, [Fe(mdpo)₃]³⁺.     

Molekülordnung und Kristallinität in Polyhexamethylenadipamid

Zusammenfassung Kalorimetrische, röntgenographische und IR-spektroskopische Untersuchungen und Dichtemessungen ergaben für PA 66 eine bei anderen Polymeren unbekannte Anomalie. Die Abhängigkeit der Röntgenkristallinitätw _c und der kristallinitätsproportionalen Größen (experimentelle Schmelzwärme H ^*, IR-Bandenintensität) vom spezifischen Volumen ändert sich mit den Kiistallisationsbedingungen. Dies ist die Folge eines konformationsbedingten Übergangs zwichen zwei triklinen Modifikationen unterschiedlicher Dichte. Für aus der Schmelze, dem Glaszustand und verdünnter Lösung kristallisierte Proben treten bei allen drei Meßmethoden hinsichtlich der Abhängigkeit vom spezifischen Volumen drei Bereiche auf. Bereich I: Die Proben enthalten 1-Kristalle mit _c ^I =1,22 =1,22 gcm-³,H _M ^I =235 Jg^–1 und=1,095 gcm _u–3. Bereich II: Die Proben enthalten _II -Kristalle mit _cII=1,165 gcm^–3.H _M ^II =185 Jg _u ^–1 1 und pa =1,095 gcm^–3. Bereich III: Übergangsbereich, in dem sich das spezifische Volumen stärker ändert als we und H ^*, weil die Kristalldichte zwischen _c ^I und ell variiert.Die _c -Wertr wurden außer durch Extrapolation über dem spezifischen Volumen auch aus der Invarianten der Röntgenkleinwinkelstreuung bestimmt. In allen Fällen ist eine .röntgenographische Kristallinitätsbestimmung bei PA 66 willkürfrei und reproduzierbar möglich. Aus Dichte oder Schmelzwärme kannw _c unter Verwendung der ermittelten _c- und H_M-Werte nur bestimmt werden, falls die Proben den Bereichen I oder II angehören. Mit den üblichen Verarbeitungsmethoden erhält man jedoch meist Proben im Bereich III.

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Summary From the results of calorimetric, X-ray and infrared spectroscopic investigations and density measurements an anomaly is found for polyamide 66 which is not known for other polymers. The dependence of X-ray crystallinityw _c and other properties proportional to crystallinity (experimental heat of fusion H ^*, intensity of IR-absorptions) on the specific volume varies with the conditions of crystallization. This is due to a conformational transition between two triclinic modifications with different densities.Samples of polyamide 66 were isothermally crystallized from the melt, from dilute solution and from the glassy state at different crystallization temperatures. The results of each of the three experimental methods, when plotted versus specific volume, exhibit three sections Section I: The samples contain _I -crystals with _c =1.22 gcm^–3, H _M ^I = 235 Jg^–1 and _a =1.095 gcm^–3 Section II: The samples contain air-crystals with _c ^I =1.165 gcm-3, H _M ^II =185 Jg^–1 and ppa =1.095 gcm^–s; Section III: Transition range, where the change in the specific volume is greater than that inw _c and H ^*, because the crystal density varies continuously between _c ^I and _c ^II The crystal densities have been determined not only by specific volume extrapolations, but also from the mean square electron density fluctuation of the small angle X-ray scattering. In all cases it is possible to determine the crystallinity of polyamide 66 from X-ray measurements in an unequivocal and reproducible way. The calculation of crystallinity from density or heat of fusion is only possible, if the samples belong to section I or II. The usual processing methods, however, produce samples which belong to section III.

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Mit 15 Abbildungen und 2 Tabellen

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Herrn Professor Dr. Horst Pommer zum 60. Ge burtstag gewidmet.     

Thermal analysis of metal complexes,III

On the basis of the thermal investigation of Mpy_nX _z mixed complexes (where M=Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺; py=pyridine; or-, - and-picoline; X=Cl^–, Br^–, I^–, OCN^–, SCN^–, NO ₃ ^– , SO ₄ ^2– ; andn=2,3,4,6;z=1,2), factors influencing the stability of the metal-pyridine-N bond have been determined.On the basis of the measured magnetic susceptibilities the symmetry of the coordina tion sphere of the central atom has been established in the intermediate products formed by the thermal decomposition of cobalt(II) complexes.

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Zusammenfassung Aufgrund derivatographischer Untersuchungen von Mischkomplexen des Typs Mpy_nX_z (M=Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺; py=Pyridin,, und Piccolin; X=Cl^–, Br^–, I^–, OCN^–, SCN^–, NO ₃ ^– , SO ₄ ^2– ;n=2, 3, 4, 6;z=1, 2) wurden die die StabilitÄt der Metall-Pyridin-N Bindung beeinflussenden Faktoren geprüft. Durch Messung der magnetischen SuszeptibilitÄten wurde die Symmetrie der KoordinationssphÄre des Zentralatoms des bei der thermischen Zersetzung entstehenden Kobalt(II)-komplexes ermittelt.

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Résumé On a examiné des complexes du type Mpy _n X _z (où M=Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺; py=pyridine,-,- et-piccoline; X=Cl^–, Br^–, I^–, OCN^–, SCN^–, NO ₃ ^– , SO ₄ ^2– ;n=2, 3, 4, 6;z=1, 2) dans le but de déterminer les facteurs ayant une influence sur la stabilité de la liaison métal-pyridine-N. Par mesure des susceptibilités magnétiques, on a pu établir dans la cas des complexes du Co²⁺ la sphère de coordination de l'atome central pour les phases intermédiaires produites par décomposition thermique.

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_nz ( M=n²⁺, ²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺; py= , , ; X=Cl^–, Br^–, I^–, OCN^–, SCN^–, NO₃ ^–, SO ₄ ^2– ; n=2, 3, 4, 6; z=1, 2) , --N. , (II).

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Previous paper of the series: G. Liptay, K. Burger, E. Papp Molnár, Sz. Szebeni, F. Ruff: J. Inorg. Nucl. Chem. 31 (1969) 2359.

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We are indebted to Miss é. Szabó for technical assistance.     

The UV spectra of arsines and arsine selenides

Short-wavelength n_Se ^* and long-wavelength n_Se ^* bands are observed in the UV spectra of saturated trialkylarsine selenides in the near-UV region. The n_x ^* band in going from arsine selenides to arsine sulfide and then to arsine oxides is shifted hypsochromically, as in the corresponding phosphorus compounds. The n_x ^* band is only slightly sensitive to the chalcogen. Saturated trialkylarsines, in contrast to alkylphosphines, absorb in the near UV region (the n_As ^* band is at 208 nm).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 940–942, April, 1990.     

Solvent extraction and spectrophotometric including graphite furnace atomic absorption determination of molybdenum in the environment

A selective and sensitive method for the extraction and microgram determination of molybdenum (VI) with hydroxamic acid as yellow molybdenum-hydroxamate complex from acidic medium is described. The molybdenum-PCPPSAHA complex has _max 388 nm, molar absorptivity 5.0 × 10³l mol^–1 cm^–1. The system obeys Beer's law in the range of 1–28 g/ml of molybdenum(VI). Sandell's sensitivity is 0.0192 g cm² and stoichiometry of the complex is 12, molybdenum: PCPPSAHA while mixed complex molybdenum-PCPPSAHA-morin has _max 400 nm and molar absorptivity 5.9 × 10³lmo1^–1 cm^–1 and stoichiometry of the complex is 121.The molybdenum is determined by graphite furnace atomic absorption spectrophotometry after directly pipetted the extract into the furnace which increases the sensitivity 20 fold.     

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)].     

Nonadiabatic transitions at the limit of almost-adiabatic perturbations with random motion along the terms

Conclusions The investigation carried out has shown that in the diffusion approximation, which is valid when the effective length of the free path =v_ov is much smaller than the dimension of the nonadiabatic region, an adiabatic limit is achieved only under the condition v_v 1. This case cannot be described when (4) is assumed to be valid for , since this equation is fulfilled only when v_v 1. It is perfectly natural that the use of Eq. (4) produces a strong interaction between the terms of the quantum subsystem, i.e., we do not attain an adiabatic limit. In the work it was shown that at the adiabatic limit the rate of transitions between the terms decreases rapidly with increasing v_v.The condition v_v 1 strongly restricts the region for the applicability of (4) and, therefore, of (12). In this sense, expression (21) is a significant generalization of (14), since it was obtained only under the. assumption and V_D 1. However, the range of parameters which satisfy these inequalities corresponds to a fairly narrow group of processes; therefore, it would be of interest to also investigate the region of a. This question will be the subject of the next report.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 17, No. 1, pp.3–9, January–February, 1981.In conclusion, we express our sincerest thanks to I. V. Aleksandrov, S. Ya. Umanskii, and M. Ya. Ovchinnikova for numerous and useful discussions.     

Pt(II) complexes in activation of saturated hydrocarbons

The rate constants of deuterium exchange for cyclohexane in CH₃COOD/D₂O have been measured in the presence of 12 complexes of Pt(II) with various ligands (Cl, H₂O, NH₃, Br, NO₂, py, DMSO, PPh₃, etc.). The change in the rate constant is shown to follow the reverse series of the trans-effect of Pt(II) ligands. The rate constant of the interaction of PtCl₂S_n (S is H₂O, CH₃COOH, n=1, 2) with cyclohexane in CH₃COOD/D₂O (11), k, equals 2.5×10⁸ exp (–18200/RT) 1 mol^–1 sec^–1 (at 354–385 K). The ratio of rate constants for PtCl₂S₂, PtCl₃S^– and PtCl ₄ ^2– is 10060.5 at 100°C.

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CH₃COOD–D₂O 12- Pt(II) (Cl, H₂O, NH₃, Br, NO₂, , DMCO, PPh₃ .). , Pt(II). PtCl₂S_n (S–H₂O, CH₃COOH, n=1,2) 11 CH₃COOD–D₂O k=2,5·10⁸ exp(–18200/RT). ^{–1 –1} (354–385°). 100°C PtCl₂S₂, PtCl₃S^– PtCl ₄ ^2– 10060,5.

     

Temperature programmed desorption of NH3 and H2O from NH4NaX and CoNH4NaX zeolites

A study has been made of temperature programmed desorption (TPD) of NH₃ and H₂O from samples of NH₄X and CoNH₄X zeolites of various degree of exchange. NH₃ TPD peaks could be explained by interaction of NH₃ with different Brönsted and Lewis acidic centers. Moreover a water peak at high temperatures allowed interpretations of the dehydroxylation, and by reason of the characteristic desorption temperatures a particular state of the Co²⁺ ions in the CoNH₄X zeolites is postulated.

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- () NH₃ H₂O NH₄X CoNH₄X . NH₃ NH₃ =qs . . Co²⁺ CoNH₄X.

     

Autocatalysis in the formose reaction

It has been found that carbohydrates naturally present in ppm quantities in paraformaldehyde are the cause of the autocatalysis in the formose reaction of paraformaldehyde solutions. Paraformaldehyde sublimed into Ca(OH)₂ suspension was not transformed to sugars by formose reaction, only to methanol and formate by Cannizzaro reaction. A minute trace of glycolaldehyde — 3 ppm — was sufficient to initiate conventional autocatalysis. A formose reaction scheme in which formaldehyde reacts only with sugars by aldol condensation but not with itself is proposed.

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, , .. . , Ca(OH)₂, , , . — 3 .. — . , , .

     

On theC v toC p conversion for solid linear macromolecules

TheC _v toC _p conversion for solid linear macromolecules via the Nernst-Lindemann equationC _p -C _v =A ₀,C _p ² T/T_m is discussed on hand of data for 10 crystals and seven glasses. An average value ofA ₀=(5.11±2.41) · 10^–3 mol K J^–1 was calculated if the mole is assumed to refer to heavy atoms only. ThisA ₀ is numerically equal to the original Nernst—Lindemann constant.

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Zusammenfassung An Hand von sich auf 10 Kristalle und 7 Gläser beziehenden Daten wird die Umrechnung vonC _v -inC _p -Werte für feste lineare Makromoleküle mittels der Nernst-Lindemann-GleichungC _p -C _v =A ₀ C _p ² T/T _m diskutiert. Ein Durchschnittswert vonA ₀=(5.11±2.41) · 10^–3 mol K J^–1 wurde unter der Annahme berechnet, daß sich das Mol nur auf schwere Atome bezieht. DieserA ₀-Wert ist numerisch gleich der ursprünglichen Nerns-Lindemann-Konstanten.

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10 , - C _v C _p , —C _p –C _v = _{0 p} ² / . , , ₀ (5.11±2.41) · 10^–3 · ^–1. ₀ — .

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Support by the National Science Foundation, Polymers Program (Grant No. DMR 83-17097) is gratefully acknowledged.     

Alkaloids ofRhinopetalum stenantherum. II. The structure of stenanthine and stenanthidine

From a methanolic extract of the epigeal part ofRhinopetalum stenantherum have been isolated -chaconine (I) and the new glucoalkaloids stenanthine with mp 262–264°C []_D 46.5°, C₄₅H₇₃NO₁₅ (II), and stenanthidine with mp 269–271°C, []_D –47.5°, C₃₉H₆₃NO₁₁ (III). On the basis of the facts that partial hydrolysis of the trioside (II) formed the biosides (I) and (III), and that on the hydrolysis of the latter the monoside -chaconine was found, it may be assumed that stenanthine has the structure of solanidine 3-0-{[0--D-glucosyl-(1 6)]-[0--L-rhamnosyl-(1 4)]-D-glucoside}, and stenanthidine that of solanidine 3-0-[0--D-glucosyl-(1 6)-D-glucoside].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 349–356, May–June, 1981.     

“Blue silver”: transformation of clusters and metal coagulation

The formation and transformations of blue silver ( _max 700 nm) during -irradiation of a weakly alkaline (pH 9) aqueous solution containing AgClO₄, polyacrylic acid (PAA), and isopropanol were studied. We believe that blue silver is a linear silver cluster stabilized on a polymeric molecule. During radiation-chemical reduction the cluster is transformed into new clusters ( _max = 365 and 460 nm). When all of the Ag⁺ ions present in the solution have been reduced, clusters coalesce and a new phase,i.e., colloidal silver particles, forms. The mechanism of the radiation-chemical transformations is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 35–37, January, 1995.     

Rate constants for photochemically induced hydrogen abstraction calculated from spin trapping rates

ESR spin trapping method has been applied to calculate the rate constant for -hydrogen abstraction from ethylbenzene by triplet anthraquinone: k₁=1.1×10⁷ M^–1 s^–1 (error of estimation 25%).

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( ) -CH : k₁=1.1×10⁷ M^–1–1 ( 25%)

     

Optisch aktive aromatische Spirane, 18. Mitt.: Darstellung von optisch aktiven 4,4′-disubstituierten 2,2′-Spirobi-s-hydrindacenen

Summary All optically active title compounds were obtained from the 4,4-diacetyl-spiro compound2; (+)- and (–)-2 were accessible by chromatography on triacetyl cellulose in ethanol. The enantiomeric purities were established from chromatographic data. The chirality (–)-(2R) was deduced for all new compounds on the basis of the CD spectra of (–)-2 and (–)-2,2-spirobi-(5,6,7,8-tetrahydrobenzo[f]indane). From the molar rotations of these 4,4-disubstituted 2,2-spirobiindanes (empirical) ligand parameters were determined (using the so-called shortened approach). Generally, the values of in these compounds are higher than those of the analogous tetrahydrobenzoindane derivatives.

Herrn Prof. Dr.F. Sauter mit besten Wünschen zum 65. Geburtstag gewidmet     

Simultaneous determination of yohimbine and boldine by first-derivative synchronous spectrofluorimetry

A method for the simultaneous determination of yohimbine and boldine in mixtures by first-derivative synchronous spectrofluorimetry has been developed. The method is based on their native fluorescence in 0.1N sulphuric acid medium. The constant wavelength difference chosen to optimize the determination was =_em -_em=82 nm. Yohimbine was measured at _ex//_em= 285/367 nm, and boldine at _ex/_em=272/354 nm. The range of application is 10–500 g/l for yohimbine and 1–50 g/l for boldine. The method was applied to the determination of yohimbine and boldine in synthetic mixtures and pharmaceuticals, with errors generally 2%. Relative standard deviations were about 2%.Dedicated to Professor Fermin Capitán on his 72th birthday