Terminal moieties alkyl chains

Liquid crystals based on aliphatic isocyanides and aromatic alkynyls (compounds 16) show enantiotropic nematic phases between 110 and 160 °C. Important reductions in the transition temperatures, mainly in clearing points (<100 °C), areobtained when a branched octyl isocyanide is used. The nematic phase stability is also reduced and the complexes are thermally more stable than derivatives of aliphatic alkynes. Other structural variations such as the introduction of a lateral chlorine atom on one ring of the phenyl benzoate moiety or the use of a branched terminal alkyl chain produce a decrease of the transition temperatures enhancing the formation of enantiotropic nematic phases without decomposition. 

Terminal crown ethers with taper-shaped substituents often possess columnar phases. Sometimes, the columnar order is only observed after the complexation of specific salts. The uptake of salts often results in the crown ethers assembling side by side forming supramolecular cylinders with the crown moieties on the inside and the alkyl chains on the outside leading to possible ion-conducting arrangements within an insulating jacket. Indeed, it was shown that matrix-fixed tubular arrangements are ion conductors. 

The steric demand of the zirconocene moiety leads to rearrangements in the case of hydrozirconation of internal double bonds. Regardless of position or configuration of the double bond in the substrate, zirconium migrates to the terminal position of the alkyl chain via insertion and /TH-elimination steps. Such isomerization does not occur upon hydrozirconization of internal alkynes. 

Starburst PAMAM dendrimers (Fig. 1), a specific class of commercially available dendrimers that have repeating amine/amide branching units, have drawn considerable interest in recent years due to their potential applications in medicine, nanotechnology, and catalysis [3-7]. These dendrimers are readily functionalized to terminate in diverse moieties such as primary amines, carboxylates, hydroxyls, or hydrophobic alkyl chains. Because dendrimer size and end groups can be varied, they are typically named by their generation (Gl, G2, etc.) and exterior functionality (- NH2, - OH). 

Diols have been rarely observed in insect cuticular lipids (Buckner, 1993). Odd-carbon-number diols (C23-C29) were the major lipid class (55%) of the larval cuticular lipids from the flour beetle, Tenebrio molitor (Bursell and Clements, 1967). The major diol constituent was 8, 9-pentacosanediol. For the cuticular lipids of M. sexta larvae, very small amounts (<1%) of 7,8- and 8,9-C27 diols and 8,9- and 9,10-C29 diols were identified (Espelie and Bernays, 1989). Hydroxy n-alkanols are diols with a hydroxyl functional group on the C, position (terminal) of the alkyl chain, but are technically not alcohol derivatives of hydrocarbons. There are a few reports of the occurrence of insect hydroxy -alkanols (Buckner, 1993 Nelson and Blomquist, 1995 Buckner et al., 1996). In a structure analysis study of beeswax, the major alcohol moieties of the diester fraction were identified as 1,23-tetracosanediol (42.2%), 1,27-octacosanediol (26.0%) and 1,25-hexacosanediol (20.2%) (Tulloch, 1971). The hydroxy n-alkanols comprised 16% of the cuticular lipids of FI. zea pupae and were identified as C30-C36 even-chain n-alcohols with hydroxyl groups on carbon numbers 11, 12, 13, 14, or 15 (Buckner et al., 1996). Mass spectral analysis indicated the presence of unsaturation in the alkyl chain of the major diol components. 

Polysiloxane photoinitiators containing terminal and side-chain alkyl phenyl ketone moieties (PSCPKl, PSCPK2 and PSAPK) have also been prepared and used for promoting the polymerization of MMA under UV irradiation [86] ... 

Interestingly, neither adamantyl nor imidazole is necessary for binding Ru-wires terminating in either an alkyl chain or a perfluorobiphenyl bind to the enzyme. This observation suggests that interactions of the protein with the Ru-diimine and linker moieties provide the bulk of the binding energy. 

Non-covalent coating of cahx[4]arene-based glycocluster amphiphiles was used to bio functionalize CdSe QDs capped by TOPO. The alkyl chains of the glycocluster amphiphiles were inserted into the TOPO-coated QDs, and the terminal saccharide moieties (a- and P-glucoside, P-galactoside, and a-maltohexaoside) were exposed to bulk water to ensure solubility in aqueous buffers. Subsequently, gum arable and TOPO-QDs (CdSe/CdS) were used to produce non-toxic and biocompatible QD nanocolloids by non specific physical interactions. These glyco-QDs showed good photochemical stabilities and quantum yields. 

Replacing the terminal diamino groups of diaminoalkanes by quaternary ammonium moieties gave rise to more efficient separations [57]. Although a similar resolution was achieved with both types of additives, lower concentrations of quaternary ammonium salts were necessary and shorter migration times were obtained, an indication of effectiveness of these bis-quaternary ammonium compounds. Quaternary ammonium salts such as hexamethonium chloride and bromide and decamethonium bromide (DcBr), having alkyl chains of 6 and 10 carbon atoms, respectively, have been used for the separation of the isoforms of OVA and hCG [57], and Tf [55]. For quaternary ammonium salts, the longer alkyl chains were shown to be more effective and chloride salts led to shorter analysis time than bromide ones. 

Gold NPs with azobenzene terminated alkane thiol chains chemisorbed on the surface and complexed with a-CD gave a photoresponsive suspension in water, in which the azobenzene photosomerization was as efficient as that of the free molecule. Preferential complexation of the allgrl chain in both trans- and ds-azobenzene configurations favoured the water solubility of the alkyl-aromatic moiety and the chemisorption process and reduced the interaction between the azobenzene units on the particle surface with positive effects on the efficiency of the photoisomerization. 

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