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  • Inorganic Chemistry  (5)
  • Atomic, Molecular, and Optical Physics
  • Chaperone
  • 1995-1999  (3)
  • 1990-1994  (3)
  • 1
    ISSN: 1432-2048
    Keywords: Chaperone ; Chloroplasts ; Chromoplasts ; Heat-shock protein ; Secale
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A partial cDNA which codes for the β-subunit of a plastidic chaperonin 60 (cpn60-β) from rye (Secale cereale L.) leaves was identified and sequenced, except for 46 amino acids of the N-terminus of the mature protein and the transit sequence. This is the first cpn60-β sequence determined for a monocotyledonous plant. Specific antibodies against cpn60-β were affinity-purified from an antiserum raised against the total soluble protein fraction of ribosome-deficient plastids. The localization of cpn60-β in chloroplasts or non-green plastids was confirmed by immunodetection in Percoll gradient-purified organelles. The expression and occurrence of cpn60-β was analysed by immunoblotting with the specific antibodies and Northern hybridization. The cpn60-β protein was constitutively expressed in various green and non-green tissues. It was evenly distributed along the major part of a rye leaf, while highest transcript levels occurred in the youngest and oldest leaf sections. The expression of the cpn60-β protein was not enhanced by a heat-shock treatment at 42 °C. The cpn60-β transcript and protein were more strongly expressed in various non-green, for instance etiolated, 70S-ribosome-deficient 32 °C-grown, or herbicide-bleached tissues, than in green leaves of rye. A rapid increase in the cpn60-β transcript level was also observed when green leaves were transferred from light to darkness while the protein level was not affected. The dark-induced increase in the cpn60-β transcript was totally suppressed in the presence of 2% sucrose. Inhibitor treatments suggested that the change in cpn60-β transcript level was not related to changes of the ATP supply of the tissue. While the large subunit of the photosynthetic protein ribulose-1,5-bisphosphate carboxylase was largely degraded during ripening of tomato fruits, high levels of cpn60-β were detected in tomato chromoplasts and in the yellow flower petals of Narcissus. Low levels of cpn60-β were detected in root tissue.
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  • 2
    ISSN: 0044-2313
    Keywords: 1,2-Diphospha-3,4-diboretanes ; 1,3-diphospha-2,4,5-triborolane derivative ; preparation ; molecular structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,2-Diphospha-3,4-diboretanes and 1,3-Diphospha-2,4,5-triborolane: Synthesis and Structure as well as Calculations on the Molecular Structure On the Effect of Substituents on the Structure of 1,2-Diphospha-3,4-diboretane[2 + 2]-Cyclocondensation reactions led to the synthesis of the 1,2-diphospha-3,4-diboretanes [(t-BuP)2B2(NMe2)2], 1 a, and [(t-BuP)2B(NMe2)B(NiPr2)], 1 b. Their molecular structures have been determined by X-ray methods, and these are compared with the structure of [(t-Bu)P—BN(iPr2)]2, 2 a. Compounds 1 show a folded B2P2 four membered ring having tert.-butyl groups in anti-positions. Ab initio calculations on 1,2-diphospha-3,4-diboretanes demonstrate that two conformers with anti-orientation of the substituents at the phosphorus atoms can be expected. These differ by the relative orientation of the almost planar P2BR groups to the BP2 plane. The influence of substituents (H and NH2 at the B atoms, and H and Me at the P atoms) on the ring conformation has been studied. Finally, the first derivative of a 1,3-diphospha-2,4,5-triborolane, 3 a, is reported.
    Notes: Durch [2 + 2]-Cyclokondensationen wurden die 1,2-Diphospha-3,4-diboretane [(t-BuP)2B2(NMe2)2], 1 a, und [(t-BuP)2B(NMe2)B(NiPr2)], 1 b, dargestellt, ihre Molekülstrukturen mit Röntgenbeugungsmethoden bestimmt und mit der Struktur von [(t-Bu)P—B(NiPr2)]2, 2 a, verglichen. In den Verbindungen 1 liegen gefaltete B2P2-Vierringe vor mit anti-ständigen tert.-Butylgruppen, während das Ringsystem in 2 a planar gebaut ist, die tert.-Butylgruppen aber ebenfalls anti-Stellung einnehmen. Ab initio-Rechnungen an 1,2-Diphospha-3,4-diboretanen belegen, daß zwei unterschiedliche Konformere mit anti-Orientierung der Substituenten an den P-Atomen stabil sind, die sich durch die relative Orientierung der annähernd trigonal-planaren P2BR-Baugruppen zur BP2-Ebene voneinander unterscheiden. Der Einfluß von Substituenten (H und NH2 am B-Atom, H und CH3 am P-Atom) wird ermittelt. Beschrieben wird ferner das erste Derivat eines 1,3-Diphospha-2,4,5-triborolans, 3 a.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 608 (1992), S. 33-42 
    ISSN: 0044-2313
    Keywords: Diacylphosphines ; Di-cyclohexoylposphine ; Diadamant-1-oylphosphine ; keto-enol tautomerism ; NMR-parameters, thermodynamic data ; X-ray structure determination ; very short O‥H‥O bridge ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Acyl- and Alkylidenephosphines. XXXII. Di-cyclohexoyl- and Diadamant-1-oylphosphine - Keto-Enol Tautomerism and StructureLithium dihydrogenphosphide · DME (1) [12] and cyclo-hexoyl or adamant-1-oyl chloride react in a molar ratio of 3:2 to give lithium di-cyclo-hexoylphosphide · DME and the corresponding diadamant-1-oylphosphide.2THF (1) resp. Treatment of these two compounds with 85% tetrafluoroboric acid. diethylether adduct yields di-cyclo-hexoyl- (1b) and diadamant-1-oylphosphine (1c). In nmr spectroscopic studies 1b over a range of 203 to 343 K, a strong temperature dependence of the keto-enol equilibrium is found; thermodynamic data characteristic for the formation of the enol tautomer (ΔH0 = -4.3 kJ. mol-1; ΔS0 = -9.2 J. mol-1. K (-1) are compared of 1,3-diketones.The enol tautomer of diadamant-1-oylphosphine (E-1c) as obtained from a benzene solution in thin colourless plates, crystallizes in the monoclinic space group P21/c {a = 722.2(2); b = 1085.5(4); c = 2434.8(5) pm; ß = 96.43(2)° at -100 ± 3°C; Z = 4}. An X- ray structure analysis (Rw = 0.033) shows bond lengths and angles to be almost identical within the enolic system (P—C 179/180; C—O 130/129; C—C(adamant-1-yl) 152/153 pm; C—P—C 99°; P—C—O 124°/124°; P—C—C 120°/120°; C—C—O 116°/116°. The geometry of the very strong, but probably asymmetric O‥H‥O bridge is discussed (O—H 120/130, O‥O 245 pm).
    Notes: Aus Lithium-dihydrogenphosphid · DME (1) [12] und cyclo-Hexoyl- bzw. Adamant-1-oyl-chlorid im Molverhältnis 3:2 zugängliches Lithium-di-cyclo-hexoylphosphid · DME und -diadamant-1-oylphosphid · 2THF 1) reagieren mit 85proz. Tetrafluoroborsäure · Diethylether-Addukt zu Di-cyclo-hexoyl- 1b) und Diadamant-1-oylphosphan (1 c). Die Lage des Keto-Enol-Gleichgewichts zwischen 203 und 343 K sowie thermodynamische Daten zur Bildung des Enol-Isomers ΔH0= -4,3kJ.Mol-1; ΔS0;=-9,2 J · mol-1 · K-1 () wurden NMR-spektroskopisch an einer 2 M Lösung des bei +20°C flüssigen Di-cyclo-Hexoyl-Derivates 1b in d8-Toluol ermittelt und mit Werten von 1,3-Diketonen verglichen.Das farblose, sich aus Benzol in dünnen Plättchen abscheidende Enol-Tautomer des Diadamant-1-oylphosphans (E-1 c) kristallisiert monoklin in der Raumgruppe P21/c {a = 722,2(2) b = 1085,5(4); c = 2434,8(5) pm; ß = 96,43(2)° bei - 100 ± 3°C; Z = 4}. Nach den Ergebnissen der Röntgenstrukturanalyse (Rw=0,033) weist das Molekül in beiden des Hälften des Enolrings nahezu identische Bindungslängen und -winkel auf P—C 179/180; C—O 130/129; C—C(Adamant-1-yl) 152/153 pm; C—P—C 99°; P—C—O 124°/124°; P—C—C 120°/120°; C—C—O 116°/116°. Die Geometrie der sehr starken, aber vermutlich asymmetrischen O‥H‥O-Brücke wird diskutiert (O—H 120/130; O‥O 245 pm).
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  • 4
    ISSN: 0044-2313
    Keywords: Lithium bis(2,2-dimethylpropionl)arsenide · DME ; tetrakis(2,2-dimethylpropionyl)diarsine ; X-ray structure determination ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Acyl- and Alkylidenearsines VII Synthesis and Structure of Tetrakis(2,2-dimethylpropionyl)diarsineLithium dihydrogenarsenide and 2,2-dimethylpropionyl chloride in a molar ratio of 3:2 react at -40 to -50°C in tetrahydrofuran or 1,2-dimethoxyethane to give the corresponding etherate of lithium bis(2,2-dimethylpropionyl)arsenide (2a). Treatment of these solutions with stoichiometric amounts of 85% tetrafluoroboric acid · diethylether adduct yields yelloworange tetrakis(2,2-dimethylpropionyl)diarsine (5) in 64 or 62% yield resp., but not the expected bis (2,2-dimethylpropionyl)arsine (4a). The very air-sensitive compound crystallizes in the monoclinic space group P21/n {-100 ± 3° C; a = 1224.6(3); b = 1419.7(3); c = 1333.1(3) pm; β = 96.22(2)°; Z = 4}. According to the X-ray structure analysis (Rw = 0.036) the molecule shows synclinal conformation; the two diacylarsyl-subunits are twisted against one another by an angle of 86°. As in another acylarsine [1] the As—C distances (203 to 205 pm) were found to be significantly longer then the standard value of 196 pm. Further characteristic bond lengths and angles are: As- 242; C—O 120 to 121 pm; As—As—C 88 to 107°; As—C—O 118 to 122°
    Notes: Wird das jeweilige, aus Lithiumdihydrogenarsenid und 2,2-Dimethylpropionylchlorid im Molverhältnis 3:2 bei -40 bis -50°C in TetrahydrofuranTetrahydrofuran (THF); 1,2-Dimethoxyethan (DME); Bis( 1,2-dimethylamino)ethan (TMEDA); Tetramethylsilan (TMS). oder 1,2-Dimethoxyethan gebildete, aber nicht isolierte Etherat des Lithium-bis(2,2-dimethypropionyl)arsenids (2a) mit 85proz. Tetrafluorborsäure · Diethylether-Addukt weiter umgesetzt, so erhält man nach der üblichen Aufarbeitung des Ansatzes nicht Bis(2,2-dimethylpropionyl)arsan (4a), sondern mit 64- bzw. 62proz.Ausbeute Tetrakis(2,2-dimethylpropionyl)diarsan (5). Die äußerst oxydationsempfindliche gelborange Verbindung kristallisiert monoklin in der Raumgruppe P21/n {-100 ± 3° C; a = 1224,6(3); b = 1419,7(3); c = 1333,1(3)pm; β = 96,22(2)°; Z = 4}. Nach den Ergebnissen der Röntgenstrukturanalyse (Rw = 0,036) weist das Molekül mit zwei um 86° gegeneinander verdrehten Hälften die synclinale Konformation auf; die As—C-Abstände liegen mit 203 bis 205 pm wie in einem anderen Acylarsan [1] deutlich über dem Standard von 196 pm. Weitere Charakteristische Bindungslängen und -winkel sind: As—As242; C—O 120 bis 121 pm; As—As—C 88 bis 107°; As—C—O 118 bis 122°.
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  • 5
    ISSN: 0044-2313
    Keywords: Dicopper trihydroxide nitrite ; crystal structure ; i.r., Raman spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Lattice Vibration Spectra. LXXVI. On Basic Copper Salts  -  Crystal Structure, IR and Raman Spectra of Cu2(OH)3NO2Single-crystal X-ray as well as IR and Raman data of Cu2(OH)3NO2 are presented and discussed with respect to an order-disorder (OD) phase transition and the strength of hydrogen bonds. Cu2(OH)3NO2 crystallizes pseudosymmetrically in the monoclinic space group P21/m (Z = 2, a = 562.22(4), b = 605.94(5), c = 663.55(4) pm and β = 95.415(5)°) forming a layered structure of edge-connected, elongated CuO6 octahedra (final R value 2.5% for 1047 symmetry averaged reflections with I ≥ 2.5 μ1). The NO2- ions are on a split position with dynamic disordering at ambient temperature. On temperature lowering the disorder is frozen out with a symmetry decrease to space group P21. The disorder of the NO2- ions causes four different arrangements of OH(2)- with different strengths of the H…O hydrogen bonds present OD stretching modes in the spectra of isotopically dilute samples 2628, 2535, 2435, and 2343 cm-1 at 90 K. The OH(1)- ions form weak H…N H-bonds to the lone-pair of the nitrogen atoms of the NO2- ions (vOD 2563 cm-1).
    Notes: Die Kristallstruktur sowie die IR- und Raman-Spektren von Cu2(OH)3NO2 werden mitgeteilt und im Hinblick auf eine Ordnungs-Unordnungs(OD)-Phasenumwandlung sowie die Stärke der vorhandenen Wasserstoffbrücken diskutiert. Das basische Nitrit kristallisiert pseudosymmetrisch in der monoklinen Raumgruppe P21/m (Z = 2, R = 2,5%, 1047 symmetriegemittelte Reflexe mit 1 〉 2,5 μ1). Cu2(OH)3NO2 bildet eine Schichtenstruktur kantenverknüpfter, gestreckter CuO6-Oktaeder. Die Nitritionen befinden sich auf einer Splitlage mit dynamischer Fehlordnung bei Raumtemperatur. Bei niedrigeren Temperaturen friert die Fehlordnung unter Bildung von NO2--Zick-Zack-Ketten und Symmetrieerniedrigung zu P21 aus. Aufgrund der Fehlordnung der NO2--Ionen ergeben sich für die OH(2)--Ionen vier verschiedene Anordnungen mit entsprechend unterschiedlich starken H-Brücken (H…O). Die OH(1)--Ionen bilden H…N-Wasserstoffbrücken zum freien Elektronenpaar des N-Atoms der NO2--Ionen.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 623 (1997), S. 1945-1953 
    ISSN: 0044-2313
    Keywords: Bismutoxideiodides ; totale pressure measurements ; mass spectrometry ; thermodynamic data ; melting diagram ; barogram ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on the System Bi2O3/BiI3The temperature functions of decomposition pressures of the ternary compounds on the quasibinary line Bi2O3/BiI3 were determined by total pressure measurements and mass spectrometry. The barogram of the system was constructed and the melting diagram precised. The enthalpies of formation and the standard entropies of the solid phases were derived from the decomposition functions: (Values see Inhaltsübersicht).
    Notes: Die Temperaturabhängigkeit der Zersetzungsdrücke der auf dem quasibinären Schnitt Bi2O3/BiI3 existierenden ternären Verbindungen wurde durch Gesamtdruckmessungen mit dem Membrannullmanometer und dem Massenspektrometer ermittelt. Das Zustandsbarogramm für das System wurde aufgestellt und das Zustandsdiagramm präzisiert. Unter Zugrundelegung der Zersetzungsgleichungen wurden die Standardbildungsenthalpien und Standardentropien der festen ternären Phasen hergeleitet: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} \Delta {\rm H}_{\rm B}^{\rm o} \,({\rm BiOI, f, 298) = - 268,1} \pm {\rm 6,3}\,{\rm kJ}\,{\rm mol}^{{\rm - 1}} \\ {\rm S}^ \circ \,({\rm BiOI, f, 298) = 116,9} \pm {\rm 7,1}\,{\rm J}\,{\rm mol}^{{\rm - 1}} \,{\rm K}^{{\rm - 1}} \\ \Delta {\rm H}_{\rm B}^{\rm o} \,({\rm Bi}_{\rm 4} {\rm O}_{\rm 5} {\rm I}_{\rm 2} {\rm, f, 298) = - 1148,8} \pm 20{\rm,9}\,{\rm kJ}\,{\rm mol}^{{\rm - 1}} \\ {\rm S}^ \circ \,({\rm Bi}_{\rm 4} {\rm O}_{\rm 5} {\rm I}_{\rm 2} {\rm, f, 298) = 367,1} \pm 25{\rm,1}\,{\rm J}\,{\rm mol}^{{\rm - 1}} \,{\rm K}^{{\rm - 1}} \\ \Delta {\rm H}_{\rm B}^{\rm o} \,({\rm Bi}_{\rm 7} {\rm O}_{\rm 9} {\rm I}_{\rm 3} {\rm, f, 298) = - 2022,5} \pm 34{\rm,3}\,{\rm kJ}\,{\rm mol}^{{\rm - 1}} \\ {\rm S}^ \circ \,({\rm Bi}_{\rm 7} {\rm O}_{\rm 9} {\rm I}_{\rm 3} {\rm, f, 298) = 619,8} \pm 41{\rm,0}\,\,{\rm J}\,{\rm mol}^{{\rm - 1}} \,{\rm K}^{{\rm - 1}} \\ \Delta {\rm H}_{\rm B}^{\rm o} \,({\rm Bi}_{\rm 5} {\rm O}_{\rm 7} {\rm I, f, 298) = - 1471,2} \pm 20{\rm,1}\,{\rm kJ}\,{\rm mol}^{{\rm - 1}} \\ {\rm S}^ \circ \,({\rm Bi}_{\rm 5} {\rm O}_{\rm 7} {\rm I, f, 298) = 385,3} \pm 24{\rm,3}\,{\rm J}\,{\rm mol}^{{\rm - 1}} \,{\rm K}^{{\rm - 1}} \\ \end{array} $$\end{document}.
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