Reactions of sodium pentaphosphacyclopentadienide with half-sandwich iron complexes

Reactions of sodium pentaphosphacyclopentadienide NaP₅ with half-sandwich iron phosphine complexes gave pentaphosphaferrocenes or ferrocenes, depending on the nature and number of substituents in the cyclopentadienyl ring.     

Beiträge zur Chemie des Phosphors. 233. Li3P7O3 und Li2HP7O2 – die ersten Oxido-heptaphosphane(3)

Contributions to the Chemistry of Phosphorus. 233. Li₃P₇O₃ and Li₂HP₇O₂ – the First Oxido Heptaphosphanes(3) The novel oxido heptaphosphanes(3) Li₃P₇O₃ ( 1 ) and Li₂HP₇O₂ ( 2 ) have been obtained by the reaction of trilithium heptaphosphide with cumene hydroperoxide. The compounds 1 and 2 are also formed from lithium pentaphosphacyclopentadienide and cumene hydroperoxide. They are sensitive to oxidation and are pale yellow solids whose structures have been elucidated by means of NMR and IR spectroscopic investigations. In each case, the oxygen atoms are bonded as lithiumoxido groups exocyclically to the heptaphosphanortricyclene skeleton.     

Pyrochlore‐type tin niobate

A single crystal of Sn_1.59Nb_1.84O_6.35 was grown at 1273 K from a mixture of sodium niobate and tin(II) chloride. The structure is of pyrochlore type A₂B₂O₇. The tin is partially oxidized to tin(IV) and competes with niobium for the occupation of site B. The stereoactivity of the Sn²⁺ lone pair induces displacement of tin towards the O atoms of the tunnel.     

The pure rotational spectrum of NaCH3 ( )

The pure rotational spectrum of NaCH₃ and NaCD₃ in their states has been recorded using millimeter/sub-mm direct absorption techniques in the 300–510 GHz range. This work is the first gas-phase detection of sodium monomethyl, which was created by the reaction of sodium vapor with tetramethyl tin. Ten rotational transitions were measured for NaCH₃ for the K=0 through K=5 components and, in select cases, up to K=10, and four transitions (K=0–7) for NaCD₃. Rotational constants have been accurately determined for both isotopomers, suggesting a sodium–carbon bond length of 2.30 Å and an H–C–H bond angle of 107.3°.     

Beiträge zur Chemie des Phosphors. 172. Existenz und Charakterisierung des Pentaphosphacyclopentadienid-Anions,P5−, des Tetraphosphacyclopentadienid-Ions,P4CH−, und des Triphosphacyclobutenid-Ions,P3CH2−

Contributions to the Chemistry of Phosphorus. 172. Existence and Characterization of the Pentaphosphacyclopentadienide Anion, P₅^?, the Tetraphosphacyclopentadienide Ion, P₄CH^?, and the Triphosphacyclobutenide Ion, P₃CH₂^? The pentaphosphacyclopentadienide anion, P₅^? ( 1 ), the tetraphosphacyclopentadienide ion, P₄CH^?( 2 ), and the triphosphacyclobutenide ion, P₃CH₂^?( 3 ), are formed besides other polyphosphides by the nucleophilic cleavage of white phosphorus with sodium in diglyme. 1 also results from the reaction of lithium dihydrogenphosphide with white phosphorus and can be obtained pure in the form of a LiP₅ solution after separating the other products. The common structural feature of 1, 2 , and 3 are rings with unsubstituted P atoms of coordination number 2 that are stabilized by mesomerism.     

The surface adsorption and micelle formation of the mixed aqueous solutions of fluorocarbon and hydrocarbon surfactants: II. Sodium perfluorooctanoate-sodium decylsulfate system

The adsorption and micellar behavior of the mixed solutions of sodium perfluorooctanoate (7CFNa) and sodium decylsulfate (C₁₀SNa) have been studied at constant ion strength of 0.1m. The adsorption was calculated from the surface (and interfacial) tension-concentration curves by applying Gibbs equation. It was found that the cmc's of 7CFNa and C₁₀SNa are of nearly the same value (1.66 × 10⁻²m and 1.45 × 10⁻²m, respectively), but γ_cmc of 7CFNa solution is ∼23 mNm⁻¹, which is much lower than that of C₁₀SNa solution. This implies that 7CFNa would have a much higher surface activity than C₁₀SNa and be adsorbed preferentially; for instance, 7CFNa has a surface mole fraction of about 0.8 in the saturated adsorption layer of the 1:1 mixed solution. The mole fractions of 7CFNa at the surface are always greater than those in the bulk solutions. The adsorption at the n- heptane-aqueous solution interface is quite different from that at the air-solution surface. Here C₁₀SNa is preferentially adsorbed owing to “Mutual phobicity” between the HC-chain of n-heptane and the FC-chain of 7CFNa at the interface. All the cmc's obtained from the γ-log m relations of 7CFNa (or C₁₀SNa) in the mixed solutions have nearly the same value and the cmc-x curves show a positive deviation from the ideal case. This further indicates that in the mixed solutions of fluorocarbon and hydrocarbon surfactants no completely miscible micelle but essentially the individual micelle of each surfactant exist due to the “Mutual phobicity” between FC- and HC-chain in the micellization process.     

Synthesis and characterization of functional cyclopentasilanes

Cleavage of the exocyclic Si-Si-bond of phenyldimethysilylnonamethylcyclopentasilane 3 by sodium ethoxide followed by chlorination with acetyl chloride leads to the monofunctional chlorononamethylcyclopentasilane 5 . Subsequent hydration gives hydrononamethylcyclopentasilane 6 , which can be easily converted to the corresponding bromo and iodo derivatives 7 , 8 . Fluorononamethylcyclopentasilane can be prepared upon treatment of 7 with ZnF₂. A different but convenient synthetic pathway to the halononamethylcyclopentasilanes has also been achieved employing the corresponding trifluoromethanesulfonic acid ester 11 . The halogen derivatives—as expected—show a strong influence on the physical properties of the compounds. These functionalized cyclopentasilanes may serve as useful synthetic tools in building larger oligosilane ring systems.     

Ions with a strong symmetric H-bond in solutions of sodium acetate in acetic acid

The multiple attenuated total reflection IR spectra of solutions of sodium acetate in acetic acid have been recorded in the range from 9000 to 4000 cm^–1. The CH₃COO^– anion and an acid molecule form be complex (CH₃COO...H...OOCCH₃) with a strong symmetric H-bond.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp, 1854–1857, July, 1996.     

Syntheses in the 4,5-dihydro-1,2,4-triazin-6-one-series

A study was carried out of alkylation, acylation and aminomethylation reactions were studied in the 5-alkyl-4,5-dihydro-1,2,4-triazin-4-one series. Alkylation by alkyl halides proceeds in the presence of sodium methylate at the N ₍₁₎ and N ₍₄₎ atoms with the formation of a mixture of alkylated compounds of three types: derivatives of 4,5-dihydrotriazine, unsaturated triazine, and their dimers. Acylation with isocyanates leads to the formation of heterocyclic ureas — derivatives at the N ₍₄₎ atom. Mono- and bisaminals were obtained by the reaction of triazines with ethoxymethyldiethylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 963–970, July, 1991.     

Na3B3O3F6: Synthesis,Crystal Structure,and Ionic Conductivity

Crystalline Na₃B₃O₃F₆ was synthesized from H₃BO₃ and NaBF₄ at 623 K, alternatively NaBO₂ can be reacted with NaBF₄ at 673 K. The title compound (C2/c, a = 11.866(7), b = 6.901(4), c = 9.367(6) Å, β = 113.724(9)°) contains the cyclo‐fluorooxotriborate anion B₃O₃F₆^3–, which displays a planar B₃O₃ ring. Within the margins of experimental error, its point group symmetry is D_3h. Layers of fluorinated boroxine rings and sodium atoms are stacked in an alternating manner in parallel to the ab plane. The novel sodium fluorooxoborate is a poor sodium ion conductor with conductivities of 8.7 × 10^–5 and 3.6 × 10^–3 S · cm^–1 at 523 and 623 K, respectively.     

Determination of benzhexol hydrochloride by capillary zone electrophoresis with an end-column electrochemiluminescence detection

A capillary zone electrophoresis with end-column electrochemiluminescence (ECL) detector was described for the determination of benzhexol hydrochloride. The detection was based on the tris(2,2′-bypyridine)ruthenium(II) [Ru(bpy)₃²⁺] ECL reaction with the analyte. Electrophoresis was performed using a 25 μm i.d. uncoated capillary. 10 mM sodium phosphate buffer (pH=8.0) was used as the running buffer. The solution in the detection cell was 80 mM sodium phosphate (pH=8.0) and 5 mM Ru(bpy)₃²⁺. A linear calibration curve of three-orders of magnitude was obtained (with a correlation coefficient of >0.999) from 1.0×10⁻⁸ to 1.0×10⁻⁵ M and the limit of detection was 6.7×10⁻⁹ M (S/N=3). This just provides an easy and sensitive method to determine the active ingredient in pharmaceutical formulations.     

Étude générale sur la nature des tungstates formés à haute température au cours de diverses réactions à l'état solide

Résumé L'étude de la décomposition du paratungstate de sodium par la chaleur met en évidence la formation de tétratungstate Na₂W₄O₁₃ et de bitungstate Na₂W₂O₇. Ce dernier tungstate, existant seulement à l'état solide, présente un spectre d'absorption caractéristique. On peut l'obtenir pur en faisant agir l'anhydride tungstique sur le tungstate de sodium Na₂WO₄.

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Summary The study of the thermal decomposition of sodium paratungstate reveals the formation of sodium tetratungstate Na₂W₄O₁₃ and the bitungstate Na₂W₂O₇. The latter tungstate exists only in the solid state and gives a characteristic absorption spectrum. It may be obtained pure by causing tungstic anhydride to react with sodium tungstate Na₂WO₄.

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Zusammenfassung Das Studium der thermischen Zersetzung von Natriumparawolframat erwies die Bildung von Tetrawolframat Na₂W₄O₁₃ und von Biwolframat Na₂W₂O₇. Letzteres besteht nur in festem Zustand und bietet ein charakteristisches Spektrum. Man erhält es in reinem Zustand durch Einwirkung von Wolframtrioxyd auf Natriumwolframat Na₂WO₄.

     

Anionic oligomerization of methacrylonitrile

The anionic oligomerization of methacrylonitrile by alcoholic solutions of sodium alkoxide in dimethyl sulfoxide, methanol and ethanol was studied. The DP of the oligomers was directly proportional to the monomer concentration and inversely proportional to the alcohol concentration, in accordance with the equation DP = K[MAN]/[ROH], K being equal to K_p/K_tr. The value of K in DMSO (with sodium methoxidemethanol) was 2.9 ± 0.2, in methanol was 1.5 ± 0.1, and in ethanol (with sodium ethoxide as initiator) was 1.9 ± 0.1. The physical properties of the oligomers are given.     

The correct space group of NaPF6·H2O

The structure of sodium hexa­fluoro­phos­phate monohydrate, NaPF₆·H₂O, has been inadvertently redetermined, revealing that the previously reported space group, Imma, was assigned incorrectly, with the a and b axes interchanged. The correct space group is Pnna. The program PLATON [Spek (2003). J. Appl. Cryst. 36 , 7–13] suggested both Imma and Pmma as possible space groups, but only Pnna is consistent with the systematic absences. The inter‐ionic and hydrogen‐bonding interactions in the lattice form a three‐dimensional network.     

A Sodium Manganese Oxide Cathode by Facile Reduction for Sodium Batteries

A nonstoichiometric sodium manganese oxide (Na_xMnO_2+δ) cathode useful for sodium batteries was synthesized by an ambient‐temperature strategy that involved facile reduction of aqueous sodium permanganate in sodium iodide and subsequent heat treatment at 600 °C. Combined powder X‐ray diffraction and synchrotron X‐ray diffraction analyses confirmed the annealed sample to belong to a Na_xMnO₂ phase with a P2‐hexagonal structure. The ICP‐AES results confirmed the stoichiometry of the sample to be Na_0.53MnO_2+δ. Electron microscopy studies revealed the particle size of the electrode to be in the range of a few hundred nanometers. The Na_0.53MnO_2+δ cathode delivered an average discharge capacity of 170 mA h g^?1 with a stable plateau at 2.1 V for the initial 25 cycles versus sodium. Ex situ XANES studies confirmed the reversible intercalation of sodium into Na_0.53MnO_2+δ and suggested the accommodation of over‐stoichiometric Mn⁴⁺ ions to contribute towards the performance of the electrode.     

The New High‐Pressure Sodium Tetraborate HP‐Na2B4O7

The new polymorph of sodium tetraborate HP‐Na₂B₄O₇ was synthesized under high‐pressure / high‐temperature conditions of 6 GPa and 1000 °C in a multianvil apparatus with a Walker‐type module. HP‐Na₂B₄O₇ crystallizes with nine formula units per cell in the trigonal chiral space groups P3₂21 or P3₁21. The parameters are a = 765.5(2), c = 2142.3(4) pm, V = 1.0872(3) nm³, R₁ = 0.0581, and wR₂ = 0.0809 (all data). The crystal structure of HP‐Na₂B₄O₇ is built up from interconnected “sechser” rings of alternating corner‐sharing BO₃ and BO₄ groups.     

The sodium salt of 2‐hydroxy‐5‐nitrobenzylsulfonic acid

The structural data for sodium 2‐hydroxy‐5‐nitro­benzyl­sulfonate monohydrate, Na⁺·C₇H₆NO₆S^?·H₂O, which mimics an artificial substrate for human aryl­sulfatase A, viz. p‐­nitrocatechol sulfate, reveal that the geometric parameters of the substrate and its analogue are very similar. Two water mol­ecules, the phenolic O atom and three sulfonate O atoms form the coordination sphere of the Na⁺ ion, which is a distorted octahedron. The Na⁺ cations and the O atoms join to form a chain polymer.     

Generation of gas‐phase sodiated arenes such as [(Na3(C6H4)+] from benzene dicarboxylate salts

Upon collision‐induced activation, gaseous sodium adducts generated by electrospray ionization of disodium salts of 1,2‐ 1,3‐, and 1,4‐benzene dicarboxylic acids (m/z 233) undergo an unprecedented expulsion of CO₂ by a rearrangement process to produce an ion of m/z 189 in which all three sodium atoms are retained. When isolated in a collision cell of a tandem‐in‐space mass spectrometer, and subjected to collision‐induced dissociation (CID), only the m/z 189 ions derived from the meta and para isomers underwent a further CO₂ loss to produce a peak at m/z 145 for a sodiated arene of formula (Na₃C₆H₄)⁺. This previously unreported m/z 145 ion, which is useful to differentiate meta and para benzene dicarboxylates from their ortho isomer, is in fact the sodium adduct of phenelenedisodium. Moreover, the m/z 189 ion from all three isomers readily expelled a sodium radical to produce a peak at m/z 166 for a radical cation [(^?C₆H₄CO₂Na₂)⁺], which then eliminated CO₂ to produce a peak at m/z 122 for the distonic cation (^?C₆H₄Na₂)⁺. Copyright © 2009 John Wiley & Sons, Ltd.     

The effect of electrolyte on the micellar properties of an anionic-nonionic detergent in aqueous solution

Summary The effect of sodium chloride on the micellar properties of an anionic-nonionic detergent C₁₆H₃₃(OCH₂·CH₂)₇OSO₃Na has been investigated and the results have been compared with previous measurements on the nonionic analogue C₁₆H₃₃(OCH₂·CH₂)₇OH. Light scattering and viscosity measurements showed that, over the electrolyte concentration range studied (0–1.0M NaCl), the micelles were very much smaller (m.m.w.=74,800 in 0.1M NaCl) than those of the nonionie analogue and exhibited no similar variation of size, shape or hydration with temperature, indicating that addition of electrolyte caused insufficient shielding of the micellar charge to induce nonionic behaviour. Viscosity results suggested a reduction in the micellar hydration with increase in electrolyte concentration to a limiting value of 0.28 g H₂O/g of detergent for salt concentrations greater than 0.01M. A possible explanation of this effect is proposed. The effect of electrolyte on the c.m.c. was determined from surface tension measurements and was described by the equation, log c.m.c.=−6.4−0.54 log (c.m.c.+salt conc.) Comparison with data reported for sodium hexadecylpolyoxyethylene sulphates with shorter ethylene oxide chain lengths indicated a decrease in the c.m.c. in salt-free systems with increase in the chain length, the data obeying the equation, log c.m.c.=−3.5−0.20n wheren is the number of ethylene oxide groups in the chain.     

Facile Synthesis and in Vitro Cytotoxic Evaluation of Novel Thiadiazole,Pyrazole, and Dithiole-Androstane Derivatives

In the aim of identifying new steroidal cytotoxic agents with potential antiproliferative activity against hepatoma cell lines (Hep-G₂), we synthesized modified steroids containing the thiadiazole, pyrazole, or dithiole moiety. Epiandrosterone 1 reacted with carbon disulfide and sodium hydride to furnish α-oxoketene dithio-disodium salt 2. Treatment of 2 with the hydrazonoyl halides 5a–d produced the thiadiazole anellated androstanone 7a–d, respectively. The reaction of 1 with hydrazine hydrate produced the hydrazide adduct 8, which cyclized upon reflux in acetic acid to form the condensed pyrazoloandrostanone derivative 9. Interaction of 8 with carbon disulfide and sodium hydride formed the disodium salt 10, which reacted with ethylchloroacetate to furnish the final adduct, dithioloandrostane derivative, 13. Compounds 7a, 7d, 9, and 13 were examined for their cytotoxicity against a panel of hepatoma cell lines (Hep-G₂) using MTT assay. The results provide that, at incubation time 72 h, in DMSO, compound 7d (50 μ mol/mL) showed the most significant cytotoxic effect at P < 0.05. The higher dose (100 μ mol/mL) of compound 7d, at 48 h incubation, reversed the effect causing resistance and the growth rate return to the control level.

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