Alkylethylenes

Houk, K.N., Williams Jr., J.C., Mitchell, P.A. and Yamaguchi, K. (1981). Conformational control of reactivity and regioselectivity in singlet oxygen ene reactions Relationship to the rotational barriers of acyclic alkylethylenes. J. Am. Chem. Soc. 103, 949-951... 

Stabilization energies (S) of the ground and ionized states of alkylethylenes referred to ethylene. derived from observed changes in ionization potential (in e.v.)... 

It is interesting to note that with l,l-dimethyl-2-alkylethylenes (where the aklyl group has the general formula — CH2R see 36,39,42, 45,48,51 on p. 46) the ratio of tertiary/secondary hydroperoxides is practically 60 40, independent of the nature of R. Also, the experimental j8 values found for the compounds are 0.16-0.18 mole/liter,... 

These are compds of the general formula R-N(N02)-CH2.CH2-N(N02)-CH2.CH2-N(N02)-CH2, CH2"N(N02) -R. They were patented by Blomquist and Fiedorek (Ref 3) for use in propellants as explosive, practically non-volatile,plasticizers for NC. The dialkyl triethylenetetranitramines are obtained, together with compds of general formula R-N(N02)-CH2-N=N( 0)-0-CH2.CH2-N(N02)-CH2-CH2-N(N02)-R, when N-alkylethylene-dinitramines are treated with ethylene dibromide as described by Franchimont Klobbie (Ref 2)... 

What are the most important factors influencing the type of microemulsion Here again we have to distinguish between nonionic and ionic surfactants. For nonionic surfactants, often alkylethylene glycols, temperature is the dominating parameter for the structure of a microemulsion. For ionic surfactants, mostly SDS or CTAB, the salt concentration dominates... 

We distinguish four types of surfactant. Anionic (e.g. SDS), cationic (e.g. CTAB), nonionic (e.g. alkylethylene glycols), and zwitterionic (e.g. phosphatidyl choline). Beside conventional surfactants, Gemini, bolafarm, oligomeric and polymeric surfactants become more and more important. 

Micellization is driven by the hydrophobic effect. Estimate from measured CMCs of alkylethylene glycols, the change in the Gibbs free energy for bringing one methylene group ( CH2 ) from an aqueous medium into the interior of a micelle. 

Table 4. Rates of cycloadditions to benzonitrile oxides to alkylethylenes in CCI4 (1/mol-sec x 103)70)...

In general, dienophiles produce the ortho product in addition to small amounts of the para product. Maleic anhydride gives the 1 2 adduct 73 (Gilbert, 1980). Maleimides undergo analogous reactions. Both classes of compounds form CT complexes with benzene and its derivatives, and the reaction can be initiated by irradiation into the CT band (Bryce-Smith, 1973). Alkylethylenes, on the other hand, produce the meta adducts. 

Aziridine synthesis. Gloss and Brois devised a new synthesis in which a tetra-alkylethylene is converted into the blue monomeric chloronitroso derivative this is reduced with stannous chloride in hydrochloric acid, and the chloroamine without... 

Reaction Wave function Alkene, photocycloaddition, 366. 420-23 addition to benzene. 420 substituted, 432 Alkyl amines, tertiary. 466 Alkyl aryl ketones, 399, 402 Alkylethylenes, 420 Alkylidenecyclopropene. 57-58 N-Alkylimine, 375 Alkyl iodide, 471 Alkyl methyl ketones. 383-84 Alkyl radical, 380 Allene. 416 Ally radical. 102, 460 Allyl resonance, 461... 

S Additional information <1> (<1> not alkylethylene glycols, only trace activity with l-thio-hexadecyl-2,3-propanediol [1,2] <1> not S-alkyl-al-kylglycerols, 2-hexadecylglycerol, 3-hexadecyl-sn-glycerol, 1-hexadecyl-ethylene glycol [1] <1> not 3-alkyl-sn-glycerols [2]) [1, 2]... 

A compromise between LDPE and HDPE has been achieved in the commercial development of linear low density polyethylenes (LLDPEs), which are a series of polymers in which ethylene is copolymerised with a small proportion of other alkylethylenes. This gives controlled branching without sacrificing or toughness. 

The preparation of functional polymers by chemical modification has been extensively used to modify the properties of polymers for various technological applications [53-58]. Chemical modification affords new classes of polymers which cannot be prepared by direct polymerization of monomers owing to their instability or nonreactivity. Also it is possible to modify the structure and physical properties of commercial polymers making them more suitable for specific applications [3]. For example, attempts to prepare linear poly(A-alkylethylenimine)s directly by ringopening polymerization of A-alkylethylene imines were unsuccessful but these... 

Abe et ah have studied the conformational characteristics of a series of poly[oxy(-l-alkylethylenes)]. In the first paper a comparison of the statistical weights of various conformations in poly(propylene oxide), deduced from the solution properties of isotactic and atactic chains, were compared with conformational weights derived from a potential-energy surface, and an anomeric effect identified with a discrepancy between the two. Flexible side-chains influence the main chain in a manner which is expressible in the statistical weight matrices. The dimensions of these chains are strongly influenced by their tacticity. Polymer chains containing both sulphur and oxygen heteroatoms have received the attention of... 

Typical chain polymerizations are those of monomers containing the carbon-carbon double bond, e.g., ethylene, isobutylene, isoprene, styrene and acrylonitrile. Polymerization is initiated by radical, cationic, anionic or Ziegler-Natta (coordination) initiators. All monomers except 1-alkylethylenes, 1,1-dialkylethylenes and vinyl ethers undergo radical polymerization. Ionic chain polymerizations are much more selective than radical polymerizations. Cationic initiation is limited to monomers containing electron-donating substituents, e.g., alkoxy, 1,1-dialkyl, phenyl and vinyl. Anionic initiation is limited to monomers with electron-withdrawing substituents, e.g., CN, COOR, phenyl and vinyl. 1-Alkylethylenes such as propylene are polymerized only by... 

Et3B-initiated radical addition of various alkyl iodides to TMSA occurs with high regioselectivity, giving (Z)-l-iodo-l-trimethylsilyl-2-alkylethylenes stereospecifically (eq 13). ... 

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