Linking groups hexyl

Scheme 15.4. Silica structure incorporating hexyl links and vinyl groups for reinforcement with polystyrene. Reprinted from [18], Copyright 2009 American Chemical Society.

Figure 15.5. Repeat compression cycles of A. a styrene-reinforced aerogel monolith without flexible linking groups and (density = 0.122g/cm, surface area = 366 mVg) B. a st5rrcne-rcinforced monolith with 49 mol% Si derived fnrni hexyl-linked BTMSH (density = 0.232 g/cm, surface area =158 mVg tmd C. the monolith from B. before and after two compressirms. Reprinted from [18], Copyright 2009 American Chemical Society.

Currently available BAS include cholestyramine, colestipol and colesevelam hydrochloride (colestimide). Cholestyramine comprises a long-chain polymer of styrene with divinylbenzene trimethylbenzylammonium groups, whereas colestipol is a long-chain polymer of l-chloro-2,3-epoxypropane with diethylenetriamine. Colesevelam HCl is poly(allylamine hydrochloride) cross-linked with epichlorohydrin and alkylated with 1-bromodecane and 6-bromo-hexyl-trimethylammonium bromide. Bile-acid binding is enhanced and stabilised in the latter compound by long hydrophobic sidechains, increased density of primary amines, and quaternary amine sidechains. For this reason, colesevelam HCl exhibits increased affinity, specificity and capacity to bind bile acids compared with the other BAS. Colesevelam HCl also binds dihydroxy and trihydroxy bile acids with equal affinity, contrasting with cholestyramine and colestipol that preferentially bind dihydroxy bile acids (CDCA and deoxycholic acid). The latter BAS can lead to an imbalance towards trihydroxy bile acids and a more hydrophilic bile-acid pool. 

Photodecomposition of azo compounds can be brought about by single electron transfer. Thus sensitization of (14) (Scheme 6) by 9,10-dicyanoanthra-cene (DCA) results in the formation of the trityl cation and a phenyl radical. Photocleavable surfactants have several potential applications, e.g. in water-based paints and coatings and in advanced drug-delivery systems. The azo group can be used to provide a photocleavable link between the tail and headgroup of a surfactant molecule, and a number of such surfactants, based on the azosulfonate functionality, have been synthesized (15, R = hexyl, octyl, decyl and dodecyl). When aqueous solutions of these surfactants are photolysed, N2 and the sulfite... 

The effect of the nature of the terminal group and the position of the imine link has also been investigated. Thus, when hexyl chains are substituted at each end of a rhenium complex with the same motif as 12, a nematic phase was observed (Cr 129N 167 1). Moreover, when one of the two hexyl chains were replaced by one (Figure 28) or two perfluorinated chains, the mesophase was changed to SmA phase, and occurred at higher temperatures, with decomposition taking place in the mesophase. ... 

In a PHIC chain, the backbone, covered by a corona of hexyl groups, consists of a Unear sequence of imide units. Their counterparts in the PS-PCEMA nanofiber are the cross-linked PCEMA cylindrical core and the PS chains as the corona. Other than the size difference, the PHIC molecule and the PS-PCEMA nanofiber bear a remarkable structural resemblance. If the PCEMA crosslinking density is high, the PtBA chains in a PS-PCEMA-PtBA nanofiber and the PAA chains in a PS-PCEMA-PAA nanotube become trapped inside the cores even if the solvent is good for both PtBA and PAA. Thus, the triblock copolymer nanofibers and nanotubes can be viewed as giant polymer chains as well [18]. 

R)- and (S)-l,l -bi-naphthyl-2,2 -di-[pflrfl-(frflMS-4-M-pentylcyclohexyl)phenoxy-l-hexyl]ether were synthesized through the Williamson etherification reactions of chiroptical ( )-(+)- and (S)-(—)-l,l -bi-2-naphthols, respectively, with phenylcyclohexyl (PCH) derivatives. The products will hereafter be abbreviated as R)- and (S)-PCH506-Binol (Scheme 3.1). The suhstituent is composed of PCH moiety, M-pentyl group (the number of carbon of 5), and hexamethylene chain linked with an ether-type oxygen atom, [-(CH2)sO-, 06], hence abbreviated as PCH506. 

P-Amylase has been reversibly immobilized, with retention of activity, by hydrophobic attachment to hexyl-substituted, epichlorohydrin-cross-linked agarose and to octyl-substituted, epichlorohydrin-cross-linked agarose containing mercapto-groups in the side-chains. 

Agarose cross-linked with epichlorohydrin reacted with 1-bromohexane to give a derivative that adsorbed p-amylase in an active form. " Hexyl- and octyl-substituted, epichlorohydrin-cross-linked agaroses containing mercapto-groups on the side-chains have been used for the reversible immobilization of P-amylase and glucoamylase. ... 

The reaction has been extended to internal alkynes as substrates (Scheme 1.44) [12]. Under slightly milder conditions, almost full conversion was noted. Most of the a,P-unsaturated aldehydes formed were obtained in good to excellent yields. Interestingly, with the terminal alkyne 1-octyne, a-hexyl acrolein was obtained only in 17% yield. In unsymmetrically substituted alkyl-aryl-alkynes, the formyl group was predominantly linked to the neighboring aryl substituent. Bulky alkyl groups forced the C-C bond formation reaction in the P position. 

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