Surface properties of diluted solutions of cyclohexanol and cyclopentanol in ethylene glycol

The surface tension, sigma, of dilute solutions of cyclohexanol and cyclopentanol in ethylene glycol was measured in the temperature range between 293.15 and 323.15 K by means of the ring detachment method. The surface entropies and enthalpies were calculated. The surface excess values were obtained using the Gibbs equation. The surface tension data were analyzed using the extended Langmuir (EL) model and the surface composition were obtained from this model. It was shown that clathrate-like solvates (hydrophobic-like solvation) are forming in the dilute solution of cyclohexanol in ethylene glycol.     

A novel one-pot,four component synthesis of some densely functionalized pyrroles

A new one-pot four component procedure for synthesis of densely functionalized pyrroles using commercially available ninhydrin with phosphorane intermediates produced in the reaction between triphenylphosphine, ammonium thiocyanate (or ammonium acetate) and various dialkyl acetylenedicarboxylates was developed.     

Der Einflu? des Partialdruckes auf die Geschwindigkeit der kathodischen Sauerstoff-Reduktion

Ohne Zusammenfassung     

One-Pot,Three-Component Synthesis of Pyrimido[4,5-b]quinoline-tetraone Derivatives in Water

Novel pyrimido[4,5-b]quinoline-tetraones were prepared by the three-component reaction of 2-hydroxynaphthalene-1,4-dione, 6-amino-uracils, and aromatic aldehydes in aqueous media and catalyzed by p-toluenesulfonic acid. This protocol provides a simple one-step procedure with the advantages of easy workup, good yield of products, and environmental friendliness.     

Tributylphosphine Catalyzed O -Vinylation of 3-Hydroxy-2-methyl-4 H -pyran-4-one

Protonation of the highly reactive 1:1 intermediates produced in the reaction between tributylphosphine and dimethyl acetylenedicarboxylate by 3-hydroxy-2-methyl-4 H -pyran-4-one leads to vinyltributylphosphonium salts, which undergo an addition-elimination reaction in CH 2 Cl 2 at room temperature to produce dimethyl 2-[(2-methyl-4-oxo-4 H -pyran-3-yl)oxy]-2-butenedioate (1:1 mixtures of E and Z isomers) in fairly good yields.     

Synthesis and characterization of some new organometallic complexes obtained by the reaction of bis(anilino)phosphine oxide with TiCl4 and Cp2ZrCl2

The bis(anilino)phosphine oxide (PhNH)₂P(O)H as a ligand reacts directly with zirconocene dichloride CP₂ZrCl₂ to afford H(PhNH)P[(NPh)OZr(Cp)₂Cl] (1), while in the presence of triethylamine as a base the ligand is deprotonated and H(O)P[(NPh)₂Zr(Cp)₂] (2) is isolated in a very good yield. When the ligand is treated with TiCl₄, however, the diligand complex Cl₃TiO(NPh)PH(NPh)PHO(Nph)TiCl₃ (3) is separated in high yield. These new compounds have been fully characterized by FT-IR, UV–Vis spectrophotometry and multi-nuclear (¹H, ³¹P) NMR spectroscopy and elemental analysis as well as XRF analysis of SEM images.     

Reactions of 6‐Aminouracils: The First Simple,Fast, and Highly Efficient Synthesis of bis(6‐Aminopyrimidonyl)methanes (BAPMs) Using Thermal or Microwave‐Assisted Solvent‐Free Methods

A detailed study on the condensation reaction of 6‐aminouracils and aldehydes has been investigated, and accordingly we established for the first time two green, fast, and highly efficient methods for the preparation of bis(6‐aminopyrimidonyl)methanes (BAPMs).     

(η5-Pentamethylcyclopentadienyl)trimethyltitanium as a precursor for the syndiospecific polymerization of styrene

An equimolar mixture of Cp*Ti(CH₃)₃ (2) and Ph₃C⁺[B(C₆F₅)₄]^? (1) forms a highly active and syndioselective catalyst for the polymerization of styrene, producing 96% syndiotactic polystyrene (PS) at an activity of 0.91 × 10⁷ g PS (mol Ti)^?1 (mol styrene)^?1 h^?1. Both activity and syndioselectivity can be increased using tri–isobutylaluminum (TIBA) to scavenge the system. ESR measurements indicate that the polymerization proceeds via titanium(IV) intermediates. Catalysts derived from 2/methylaluminoxane (MAO) as well as Cp*TiCl₃/MAO also function as syndioselective styrene polymerization catalysts, but are less active than the ‘cationic’; system derived from 1 and 2.     

Clean synthesis of novel spiro[indene-2, 2'-[1, 3, 5]-oxathiazine]-1, 3-diones in water

In this work, we have designed an efficient and convenient method for the synthesis of novel spiro[indene-2,2'-[1,3,5]oxathiazine]-1,3-diones by the one-pot, three component condensation of tetramethyl guanidine, ninhydrin, and isothiocyanates in water. Easy purification, green reaction conditions, easy performance and good yields are some advantages of this procedure.