Dendritic molecule dendron

Additional support for this disassembly mechanism was obtained by monitoring the release of the pyrene tail units by fluorescence spectroscopy. The confined proximity of the pyrene units in the dendritic molecule results in formation of excimers. The excimer fluorescence generates a broad band at a wavelength of 470 nm in the emission spectrum of dendron 31 (Fig. 5.25). Upon the release of the pyrene units from the dendritic platform, the 470 nm band disappeared from... 

Dendritic molecules 33 and 34 were then incubated with PGA in PBS (pH 7.4) at 37 °C. Control solutions were composed of buffer without the enzyme. The sequential fragmentation illustrated in Fig. 5.31 was monitored by observing the disappearance of dendrons 33 or 34 and the release of 4-nitroaniline by RP-HPLC. As expected, dendron 33 could not be activated by PGA and remained intact for 72 h (data not shown). However, dendron 34 showed clear activation upon incubation with PGA and its corresponding peak completely disappeared from the HPLC chromatogram as 4-nitroaniline appeared (Fig. 5.32). No 4-nitroaniline was observed in the control experiment when dendron 34 was incubated in the buffer without PGA. 

Dendritic molecules, forming predominately hexagonal columnar and micellar cubic phases, have been introduced and intensively investigated by Percec et al. and this field has recently been reviewed [143], The mesophases of these dendrons can also be stabilized and modified by replacing alkyl chains by fluorinated chains selected examples will be discussed in the next sections. 

Rule 3 If a molecule contains one dendritic structure part or only different ones, the dendritic structures (=dendrons) are treated as substituents and are assigned the suffix -cascadyl. If at least two dendrons in a molecule are of the same kind, then the name is given the suffix -cascadane (Fig. 1.22). 

Dendritic molecules may possibly be of use in nanoscale impellers or valves . For this purpose azobenzene dendrons [80] with terminal hydroxyl groups (Fig. 8.27) were covalently fixed in the interior of well-defined silicon dioxide nanotubes. In the sol/gel process, the hydroxyl groups lead to incorporation of azobenzene groups into the Si02 nanotubes being formed (Fig. 8.26) [81]. 

Dendronized polymers are a class of polymers produced by the combination of linear polymers and dendritic molecules as side chain pendant moieties [67-69],... 

Two series of triazine-based dendrons were efficiently prepared by a convergent method and their properties studied <06OL1541>. A practical syntheis of [l,3,5]triazine dendritic molecules on solid supports has been described <06MI2248>. 

Dendronized polymers, a type of dendritic molecule, exhibit properties not only from the dendron they possess - high functionality and regularity - but also from the polymer segments that are connected to dendrons or used to coimect several dendrons. Many different architectures of dendronized polymers can be prepared, depending on the t5q)e of polymer used, where the dendrons are attached, and how many are introduced. These architectures include, among others, dendron-coil, dendron-rod, dendron-rod-coil, and dendron-coil-dendron. The dendron-mediated assembly of dendronized polymers has been reviewed by Rosen et al7 ... 

Hirsch and Bbttcher synthesized a notable example of amphiphilic dendritic molecules 48 (Figure 15) selfassembling to form micelles. The dendron contained a central calixarine with two amine-terminated dendrons on the... 

Dendron A structural component of a dendritic molecule or a monofunctionalized dendritic molecule. 

Fig. 1.5 Schematic illustration of the self-assembly of dendritic building blocks, (a) Untemplated assembly of dendrons. (b) Templated assembly of dendrons. (c) Nanoparticles with assembled dendritic surface groups, (d) One-dimensional, fibrous, gel-phase assemblies of dendritic molecules, (e) Liquid crystaUine assemblies of dendritic molecules.(Reprinted from Smith et al. [50], with permission from Elsevier)...

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