Hetarylcyanamides. (Review)

The nomenclature and the synthesis of hetarylcyanamides and their reactions that take place at the cyanoamino group are discussed.     

Inorganic coordination polymers. XII. Chromium(III) tris(phosphinates)

Cohesive films of a series of chromium(III) tris(phosphinates)[Cr(OPRR′O)(OPR″-R?O)(OPR^*R^**O)]_y in which the side groups on the phosphorus are alkyl, phenyl, and/or hydrogen groups have been prepared by reaction casting or by hot pressing. The preparative reaction appears to involve conversion of an aquahydroxo or hydroxo chromium(III) bis(phosphinate) to an intermediate hydroxo bis(phosphinate) containing coordinated phosphinic acid followed by an intrachain reaction leading to the tris(phosphinate). Tensile strengths of the chromium(III) tris(phosphinates) range from 100 to 5600 psi, elongations from less than 1 to 100%. Thermogravimetric data indicate that major decomposition occurs at temperatures from 200 to 435°C in air and from 410 to 510°C in nitrogen. Infrared spectra and physical properties are interpreted to support a structure for the chromium(III) tris(phosphinates) which is based on linear, triple-bridged chains. The presence of octyl or other long alkyl side groups on the phosphorus improves the physical properties, presumably by internal plasticization, but leads to decreased thermal stability.     

Pyrylocyanines. 16. Tetraphenyl-substituted (2-pyrylo) (4-pyrylo) cyanines

Unsymmetrical tetraphenyl-substituted (2-pyrylo) (4-pyrylo) monomethylidyne-, carbo-, and dicarbocyanines and their thiopyrylium and pyridinium analogs were synthesized. The absorption spectra of these dyes were studied. The spectral characteristics of their long-wave absorption bands have values that are intermediate between the analogous characteristics of the corresponding symmetrical isomers of the and series.See [1] for communication 15.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1178–1183, September, 1982.     

Organosilane polymers. II. Poly(ethylmethyl-co-dimethylsilylene) and poly(methylpropyl-co-dimethylsilylene)

Polydimethylsilylene is a largely crystalline, high-melting polymer that is soluble only above 200°C and does not thermoform below its decomposition temperature. Introduction of ethyl and propyl substituents into the linear silylene system by random copolymerization of dimethylsilylene with ethylmethyl- and methylpropylsilylenes leads to tractable polymers that are soluble in common solvents at normal ambient temperatures.     

Heterocalixarenes. (Review)

Heterocalixarenes, i.e. heterocycle-based calixarenes, are interesting as receptors of a variety of molecules and ions. These compounds are described with regard to their syntheses, reactivity, and inclusion properties. In the presentation of benzoxazine-based calixarenes attention is paid to their chirality.     

Pyrroloquinolines. (Review)

Methods for the synthesis of six types of pyrroloquinolines with various types of ring fusion and their chemical properties are reviewed.     

Diazapyrenes. (Review)

Published data on methods for the synthesis of isomeric diazapyrenes and their properties are reviewed.     

Cavitands. (Review)

The syntheses, reactivity and complexing properties of cavitands are reviewed.     

Acyl- und Alkylidenphosphane. XVI. (Dimethylaminomethyliden)- und (Diphenylmethyliden)phosphane

Acyl- and Alkylidenephosphines. XVI. (Dimethylaminomethylidene)- and (Diphenylmethylidene) phosphines Alkyl- or arylbis(trimethylsilyl)phosphines 1 (R = mesityl, C₉H₁₁ a ; (CH₃)₃C b ; C₆H₅ c ; CH₃ d ) react only very slowly with dimethylformamide 2 and benzophenone 4. After repeated addition of small amounts of solid sodium hydroxide, however, the reaction-time is shortened from several months to a few days. The reactions between 1 a or 1 b and 2 yield the (dimethylaminomethylidene)phosphines 3 a and 3 b ; from 1 a and 4 mesityl-(diphenylmethylidene)phosphine 5 a is obtained. The formation of the thermally labile phosphines 3 d and 5 c is proved by NMR spectroscopy; these compounds dimerize very fast to give 2,4-bis(dimethylamino)-1,3-dimethyl- 10 d and 1,2,2,3,4, 4-hexaphenyl-1,3-diphosphetane 15 c. Similarly the lithium trimethylsilylphosphides 6 a , 6 c and 6 e (R = (CH₃)₃Si) react with 2 or 4 to form 3 a and 5 c as well as (diphenylmethylidene)-trimethyl-silylphosphine 5 e .