Preparation and characterization of dealuminated metakaolin and its use in the transformation of waste plastics to aromatic hydrocarbons

Acid activated metakaolins (AAMKs) have been prepared by calcination of the natural clay at 600 degrees C to provide a metakolin which was then leached at 80 degrees C for 3 h using 1M, 2M, 3M, and 6M HCl. These materials were characterized and their ability to transform the off gases from HDPE decomposition into useful aromatic species was evaluated. The amount of adsorbed water and the number of acid sites increased with the severity of acid treatment. Variable temperature DRIFTS spectroscopy of pyridine treated samples revealed that both Br?nsted and Lewis acid centers were present until 425 degrees C. Pyridine bonded to the Lewis acid centers was more thermally stable. The AAMKs were all selective to the production of toluene with respectable, but lesser, amounts of xylenes and trimethylbenzenes. This selectivity contrasts with that of acid leached and pillared smectites which are selective toward trimethylbenzene.     

Structure of the products of the cyclization in acetic anhydride of β-(2-carboxy-5-chlorophenylamino) propionic acid and its nitrile

-(2-Carboxy-5-chlorophenylamino)propionic acid cyclizes in acetic anhydride to form 4-chloro-2-(2,4-dioxopiperidino)benzoic acid, which subsequently undergoes conversion into its lactone. Under the same conditions, -[acetyl(2-carboxy-5-chlorophenyl)amino]-propionitrile forms 7-chloro-1--cyanoethyl-1,2,3,4-tetrahydroquinoline-2,4-dione. The structures of the compounds obtained were confirmed by their IR, UV, and PMR spectra. An evaluation of the stability of the ketonic and enolic forms of the compounds obtained on the basis of calculations by Hückel's method has been made.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 7, pp. 879–884, July, 1970.     

Application of a nickel hexacyanoferrate(II) composite ion exchanger to fast separation of Ra from Fr and Ba from Cs

Sorption studies of Ra, Ba, Fr and Cs on nickel hexacyanoferrate(II) composite ion exchanger from hydrochloric acid and EDTA solutions are presented.     

Synthesis and pyrolysis of (cyclobutylmethyl)trimethylsilane

Russian Chemical Bulletin -     

MO-LCAO Calculations of Polymethines

Idealized polymethines are defined as conjugated chain molecules with complete bond equilization and charge alternation. A constant π-bond order along the chain with N atoms has been derived for three types of polymethines which differ by the nature of the heteroatomic end groups. Corresponding to the number of π-electrons they are termined (N + 1)π-, Nπ- or (N ? 1)π-polymethines. This classification embraces closed shell as well as open shell systems. The relations for the energy eigenvalues, coefficients and derived quantities have been obtained in closed form. The results for the different classes of polymethines are strongly related. Their molecular properties should be similar.