Effect of the Composition of Raw Materials and Nucleating Agents. Crystallization behavior of nepheline-pyroxenic glass

Different combination of raw materials and nucleating agents were incorporated in the batch of nepheline-pyroxene glass to demonstrate their effect on the crystallization process. The effect of TiO₂, Cr₂O₃ and LiF with respect to crystallization of base glass was studied by differential thermal analysis (DTA).These materials improved the crystallization of glass between 50 to 150°C of heat treatment. When LiF+TiO₂ and TiO₂+Cr₂O₃ were put together in the glass batches, the rate of crystallization of glass was increased in the same manner. The presence of TiO₂+LiF+Cr₂O₃ improved the crystallization of the glass by decreasing the heat temperature by about 60°C. CaO/MgO and CaO/Na₂O ratios played an important role in the rate of crystal growth. The increase in the CaO/MgO ratio lowers the crystallization temperature by values ranging between 37 and 46°C. This revised version was published online in August 2006 with corrections to the Cover Date.     

Natural product chemistry,part 100: The structure of carissone,C15H24O2

Summary C₁₅H₂₄O₂,M=236.2, monoclinic, P 2₁,a=7.229(7),b=14.925 (9),c=6.235 (9) Å, =92.40 (9)°,V=672.1 ų,T=–133 °C,Z=2,D _x=1.17 g cm^–3. The X-ray diffraction analysis of this sesquiterpenoid fromCarissa opaca confirmed the previously proposed constitution of the isolate and, furthermore, allowed precise NMR assignment.

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Naturstoffchemie, 100. Mitt.: Die Struktur des Carissons, C₁₅H₂₄O₂

Zusammenfassung C₁₅H₂₄O₂,M=236.2, monoklin, P 2₁,a=7.229 (7),b=14.925 (9),c=6.235 (9) Å, =92.40 (9)°,V=672.1 ų,T=–133 °C,Z=2,D _x=1.17 g cm^–3. Die Röntgenstrukturanalyse dieses Sesquiterpenoids ausCarissa opaca bestätigte die bereits vorgeschlagene Struktur und erlaubte ferner eine genaue NMR-Zuordnung.

     

The First Cyclopentadienylalkylphosphane Nickel Chelates: Synthesis,Structures, and Reactions

The first cyclopentadienylalkylphosphane nickel chelate complexes are reported. The anionic ligand obtained by reaction of spiro[2.4]hepta‐4,6‐diene with lithium di‐tert‐butylphosphide was treated with NiCl₂ to yield [η⁵:κ¹‐(di‐tert‐butylphosphanylethyl)cyclopentadienyl]chloronickel(II). From this complex, some acetonitrile‐stabilized cationic complexes were obtained by reaction with the respective silver salts in acetonitrile. Methyl‐ and alkynylnickel chelates were prepared by reaction of the chloronickel complex with methyllithium and by copper‐mediated coupling with terminal alkynes, respectively. Some of the complexes prepared were investigated by X‐ray crystallography or cyclic voltammetry. The alkynylnickel chelates undergo cycloaddition reactions with ethoxycarbonylisothiocyanate or tetracyanoethylene, and the cyclobutenes obtained undergo ring opening to the corresponding dienes. The study includes an NMR spectroscopic investigation of the two conformers of one of these dienes.     

Polyoxoanions functionalized by diorganotin groups: the tetrameric, chiral tungstoarsenate(III), [{Sn(CH3)2(H2O)}2{Sn(CH3)2}As3(alpha-AsW9O33)4]21-

The tetrameric, hybrid organic-inorganic tungstoarsenate(III) [{Sn(CH3)2(H2O)}2{Sn(CH3)2}As3(alpha-AsW9O33)4]21- is composed of four (B-alpha-AsW9O33) fragments that are linked by three dimethyltin groups and three As(III) atoms resulting in an unprecedented, chiral polyoxoanion assembly with C1 symmetry.     

A study on combustion behaviour of carbon-sulphur-sodium nitrate mixtures

The effect of substitution of KNO₃ by NaNO₃ in black powder has been studied by DSC, TG/DTG and FTIR emission spectroscopy. Unlike KNO₃, there is no visible exothermic reaction between S and NaNO₃, immediately after the melting of NaNO₃. Instead a minor exothermic reaction is observed at higher temperature between melted NaNO₃ and adsorbed S on carbon. However, there is an increase in such reaction, when carbon black instead of charcoal is used. Infrared spectra show that CO₂ and Na₂SO₄ are major gaseous and solid products respectively. This shows that the combustion of ternary mixtures in air is different from that in N₂, with slower heating rate, in DSC or TG apparatus.

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Zusammenfassung Mittels DSC, TG/DTG und FTIR Emissionsspektroskopie wurde der Effekt des Ersatzes von KNO₃ gegen NaNO₃ in Sprengpulver untersucht. Im Gegensatz zu KNO₃ gibt es unmittelbar nach dem Schmelzen von NaNO₃ keine wahrnehmbare exotherme Reaktion zwischen S und NaNO₃. Dafür wurde bei höheren Temperaturen eine geringe exotherme Reaktion zwischen geschmolzenem NaNO₃ und an C adsorbiertem S beobachtet. Unabhängig davon werden Reaktionen begünstigt, in denen man anstelle von Holzkohle Ruß verwendet. IR-Spektren zeigen, daß die hauptsächlichen gasförmigen und festen Produkte CO₂ bzw. Na₂SO₄ sind. Dies zeigt, daß sich die Verbrennung ternärer Gemische in Luft von der in Stickstoff unterscheidet.

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We thank the Procurement Executive, Ministry of Defence for the support of this research.     

Newbouldiaquinone and newbouldiamide: a new naphthoquinone-anthraquinone coupled pigment and a new ceramide from Newbouldia laevis

Newbouldiaquinone (1), a new naphthoquinone-anthraquinone coupled pigment and a new ceramide named newbouldiamide (2), have been isolated from Newbouldia laevis, besides the known compounds lapachol (3), canthic acid, oleanolic acid, 2-methyl-9,10-anthracenedione, 2-acetylfuro-1,4-naphthoquinone, 2,3-dimethoxy-1,4-benzoquinone, 2-(4-hydroxyphenyl)ethyl triacontanoate, beta-sitosterol and beta-sitosterol glucopyranoside. The structure elucidations of the isolated new compounds were performed on the basis of spectroscopic and chemical evidence. Preliminary studies showed that 1 is moderately antibacterial against Gram-positive Bacillus megaterium and that 3 has moderate herbicidal and antibacterial activities.     

A novel isopolytungstate functionalized by ruthenium: [HW(9)O(33)Ru(II)(2)(dmso)(6)](7-)

The ruthenium-supported isopolyanion [HW(9)O(33)Ru(II)(2)(dmso)(6)](7-) (1) is composed of a nonatungstate wheel stabilized by two Ru(dmso)(3) groups, representing the first structurally characterized Ru-coordinated polyoxotungstate and a novel class of isopolyanions supporting photochromic moieties.     

Reactions with α-substituted cinnamonitriles. A novel synthesis of hexa-substituted pyridines

Whereas acetoacetanilide (II) reacted with α-cyano- and α-benzoylcinnamonitrile derivatives Ia-e to give hexa-substituted pyridines III and V, it reacted with α-carboxamido- and α-thiocarboxamidocinnammonitrile derivatives If-h to afford penta-substituted pyridines VI. One mole of acetonedicarboxylic acid dianilide (VII) reacted with two moles of each of α-cyano- and α-thiocarboxamidocinnamonitriles Ia,b,f,g to yield the dipyridyl ketones VIII and IX, respectively. On the other hand, α-benzoyl- and α-ethoxycarbonylcinnamonitriles Ic,d,i,j reacted with VII in equimolecular ratio to give the pyran derivaties X and XI, respectively. Several schemes were proposed to illustrate reactions steps. The structures of the synthesized compounds were proved by chemical and spectral methods.     

Thermal and related studies of some basic zirconium salts

Studies of basic zirconium carbonate, oxalate, nitrate and sulphate using TG, DTA and DTG methods, combined with isothermal gaseous product analyses, IR spectroscopy and X-ray diffraction techniques, have shown that the ease of ligand removal from such salts follows the sequence: loosely bound H₂O>CO ₃ ^2– C₂O ₄ ^2– >NO ₃ ^– >OH^– (or tightly bound H₂O)>SO ₄ ^2– .With the exception of the basic sulphate where the high temperature necessary for complete removal of the sulphato groups resulted in direct formation of crystalline monoclinic zirconia, such ligand removal generally led to generation of the cubic crystalline variety.

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Zusammenfassung Auf Grund von TG-, DTA- und DTG-Untersuchungen, verbunden mit einer isothermen Gasprodukteanalyse, sowie IR-spektsoskopischen und Röntgendiffraktionsuntersuchungen von basischen Zirkoniumkarbonaten, -oxalaten, -nitraten und -sulfaten wurde festgestellt, dass die relative Abspaltbarkeit eines Liganden solcher Salze der folgenden Reihenfolge entspricht: locker gebundenes H₂O>CO ₃ ^2– >C₂O ₄ ^2– >NO ₃ ^– >OH^– (bzw. stark gebundenes H₂O)>SO ₄ ^2– . Mit Ausnahme des basischen Sulfates, bei dem zur vollständigen Abspaltung der Sulfatogruppen eioe hohe Temperatur notwendig ist und sich die direkte Bildung von kristallinem, monoklinem Zirkoniumdioxid abspielt, führen solche Ligandenabspaltungen im allgemeinen zu einer kubischen Kristallmodifikation.

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, , , , , , , , : ₂> ₃ ^2– C₂Ol ₄ ^2– > N ₃ ^– > ^– — H₂O>SO ₄ ^2– . , , .

     

The alkaloidal profile of cocculus pendulus

(+)-Kohatine (5), (+)-kun-amine (7), (+)-norpenduline (11), and (+)-cheratamine (12), are four new bisbenzylisoquinolines obtained from Cocculus pendulus (Forsk) Diels (Menispermaceae). Ten known bisbenzylisoquinolines are also present. All fourteen alkaloids possess the S chirality at C-1'. The biogenetic sequence involves initial condensation of two coclaurine-type units to form a dinner such as 16. Species 16 may in turn lead to dimers 17 or 18 with two diaryl ether linkages. Only dimer 17 may undergo further oxidative coupling to bisbenzylisoquinolines with three diaryl ether bridges.