Anchoring groups

The first case concerns particles with polymer chains attached to their surfaces. This can be done using chemically (end-)grafted chains, as is often done in the study of model colloids. Alternatively, a block copolymer can be used, of which one of the blocks (the anchor group) adsorbs strongly to the particles. The polymer chains may vary from short alkane chains to high molecular weight polymers (see also section C2.6.2). The interactions between such... 

Fig. 8. General structures of polymeric dispersants (a) liomopolymer, (b) random copolymer, (c) diblock copolymer, and (d) comb polymer, where A = anchor group, B = soluble repeat unit, and C = repeat unit with solubility different from B. The repeat units may occur in sequences hundreds of...

Polymerization of methyl methacrylate in supercritical carbon dioxide with PDMS based stabilizers A study on the effect of stabilizer anchor groups... 

Simple monodentate NHCs are somewhat susceptible to dissociation when coordinated to early transition metals [6], so in most cases multidentate chelating hgands are employed in which the carbene is tethered to a strongly coordinating anchoring group. This is not universally the case however, and simple monodentate NHC complexes of Zr 1 (Fig. 4.1) have been studied [7]. The complexes were activated with MAO and tested for ethylene polymerisation, leading to moderate activities between 7 and 75 kg mol bar h for linear polyethylene. 

Chen et al. [201] investigated the single-molecule conductance of alkanes terminated with either dicarboxylic-acid, diamine, or dithiol anchoring groups. The contact resistance was again found to be dependent on the anchoring group, which varies in the order Au—S>Au—NH2>Au—COOH. 

Chen, F., Li, X., Hihath, J., Huang, Z. and Tao, N. (2006) Effect of Anchoring Groups on Single-Molecule Conductance Comparative Study of Thiol-, Amine-, and Carboxylic-Acid-Terminated Molecules. Journal of the American Chemical Society, 128, 15874-15881. 

Peukert S, Giese B. The pivaloyglycol anchor group A new platform for a photolabile linker in solid-phase synthesis. J Org Chem 1998 63 ... 

Breipohl G, Knolle J, Stuber W. Synthesis and application of acid labile anchor groups for the synthesis of peptide amides by Fmoc-solid-phase peptide synthesis. Int J Peptide Protein Res 1989 34 262-267. 

Seiber P. A new acid-labile anchor groups for the solid phase synthesis of C-terminal peptide amides by the Fmoc method. Tetrahedron Lett 1987 28 2107-2110. 

In principle, different surface sites can serve as anchoring sites but the surface OH groups are the most common anchoring groups on the oxide surfaces.225 These OH groups can take part in different reactions. For example, inorganic salts can react with the surface OH groups (Scheme 7.7).226... 

Scheme 7. The lengths of repeat units in dendrimers 22 a (8.25 A) and 23 (2.5 A) to qualitatively assess in which of them the average distance between anchor groups is smaller...

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