Hollow Silicon Carbide Nanostructures

Hollow silicon carbide nanostructures with length up to 1 m have been produced for the first time along with threadlike structures. The preparation of SiC nanostructures from silicon and carbon at 1000-1100 °C was carried out without prior gasification of these elements. The growth of SiC nanostructures involves a step featuring atomization of silicon and carbon at such low temperatures. The growth of SiC nanotubes upon the reduction of carbon by SiO₂ in the initial period of the preparation proceeds with their predominant formation as bundles. Silicon carbide may correspond to the highly textured -modification.     

Synthesis of derivatives of α-phenyldinicotinic acid and 2-phenyl-3,5-bis(5-phenyl-2-oxazolyl)-pyridine

The dichloride, diethylamide, and amide were obtained from -phenyldinicotinic acid. 2-Phenyl-3,5-diamino- and 3,5-dicyanopyridine were synthesized from the amide. 2-Phenyl-3,5-bis(5-phenyl-2-oxazolyl)pyridine and 2-phenyl-3-carboxy-5-(5-phenyl-2-oxazolyl)pyridine were obtained. The luminescence properties of the synthesized compounds were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 405–411, March, 1990.The authors thank A. A. Ustenko and E. N. Smirnova for their assistance in calculation of the spectral data.     

Di- and trimethyl-substituted 2-azafluorenes and dibasic acids of 2-azafluorenone

Dehydrocyclization of the corresponding 2,5-dimethyl-4-arylpyridines gave 3,5- and 3,8-dimethyl- and 3,5,7- and 3,5,8-trimethyl-2-azafluorenones. Dibasic acids of 2-azafluorenone were obtained from -carboxyarylcinchomeronic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1664–1667, December, 1972.     

Molecular structure of 1,2′,3′,4-tetramethyl-1′,2,3,4′-tetra(p-chlorophenyl)cyclotetrasiloxane

Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 4, pp. 161–163, July–August, 1990.     

Effect of organometallic catalysts on the synthesis process and properties of molded polyurethane

Application of organotin catalysts adversely affects the strength of polyurethane. Use of small amounts of metal acetylacetonates hardly affects the physicomechanical properties of the material, whereas their increased amounts improve the strength. It is shown that, in contrast to other catalysts, tin octoate does not accelerate the hydrolysis of the oligoester.     

Driving matrix liquid crystal displays

Liquid crystal displays had a humble beginning with wrist watches in the seventies. Continued research and development in this multi-disciplinary field have resulted in displays with increased size and complexity. After three decades of growth in performance, LCDs now offer a formidable challenge to the cathode ray tubes (CRT). A major contribution to the growth of LCD technology has come from the developments in addressing techniques used for driving matrix LCDs. There are several approaches like passive matrix addressing, active matrix addressing and plasma addressing to drive a matrix display. Passive matrix LCD has a simple construction and uses the intrinsic non-linear characteristic of the LCD for driving. Departure from conventional line by line addressing of a passive matrix has resulted in improved performance of the display. Orthogonal functions have played a crucial role in the development of passive matrix addressing. Simple orthogonal functions that are useful for driving a matrix LCD are introduced. The basics of driving several rows simultaneously (multi-line addressing) are discussed by drawing analogies from multiplexing in communication. The impact of multi-line addressing techniques on the performance of the passive matrix LCDs in comparison with the conventional technique will be discussed.     

Preparative synthesis of β-amino alcohols from α-amino dicarboxylic acid derivatives

A low-expensive preparative procedure has been developed for the synthesis of protected β-amino alcohols from α-amino dicarboxylic acid derivatives.     

Porphyrins. 25. Use of the nuclear overhauser effect for establishment of the structure of isomeric meso-substituted metalloporphyrins

Nickel complexes of the dimethyl esters of meso-dimethylaminomethyl derivatives of mesoporphyrin-II and mesoporphyrin-IX are synthesized. The structure of the prepared isomeric compounds is determined by analysis of their chromatographic properties, visible spectra, as well as of their PMR spectra using the nuclear Overhauser effect.See [1] for Communication 24.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1378–1384, October, 1989.