Propylene imine

Nonetheless, it was a fairly short step from octopus compounds to dendrimers, and the step was taken by Vogtle in the late 1970s when he attempted to use a cascade reaction to prepare a molecule of the dendrimer type that would now be considered a dendron rather than a fully developed dendrimer. It began with the addition of acrylonitrile to an anfine, followed by reduction of the nitrile to amine. This was followed by a further reaction with acrylonitrile, and the process was repeated several times to yield highly branched macromolecules. There were initially problems with the reduction step but these were overcome, and the preparation of these poly(propylene imine) dendrimers was later commercialized. 

Propylene dichluride Propylerte glycol dinilrate Propylene glycol monomethyl ether Propylene imine ... 

The molar ellipticity of these dendrimers was found to increase proportional to the number of chiral end groups. This is to be expected, in the absence of interactions between the terminal tryptophane moieties. No higher-generation dendrimers of this type have been reported. Other amino-acid-containing chiral dendrimers have been described by Meijer et al. who attached various amino acid derivatives to the periphery of poly(propylene imine) dendrimers (see Sect. 3) and more recently by Liskamp et al. (modification of polyamide dendra) [22] and Ritter et al. (synthesis of grafted polymerizable dendrimers containing L-aspartic acid components) [23]. 

Fig. 15. Optical activities of poly(propylene imine) dendrimers, functionalized at the periphery with protected phenylalanine or f-butoxy methoxy benzyl acetate groups, depend on the number of end groups [2]...

E. M. M. de Brabander-van den Berg and E. W. Meijer, Poly(propylene imine) dendrimers Large-scale synthesis by hetereogeneously catalyzed hydrogenations, Angew. Chem. Int. Ed. Engl., 32 (1993) 1308-1311. 

Figure 16.5 Reversible switching of amphiphilic azobenzene modified poly(propylene imine) dendrimer on quartz, and at the air-water interface (inset) [74]...

Figure 16.6 Schematic representation of the energy transfer process between OPV-poly(propylene imine) dendrimer and a dye guest molecule [84]...

Figure 16.7 TEM picture (uranyl acetate staining) of vesicles reported by Schenning etal. [44] (A) schematic representation of the bilayer, (B) palmitoyl-and (C) azobenzene-modified poly(propylene imine) dendrimers used in the construction of the aggregates...

Synthesis and Characterization of Poly(Propylene imine) Dendrimers... 

Dendrimers, or arborols, or cascade, or cauliflower, or starburst polymers, were first synthesized in the early 1980s [3,4]. In 1985 Tomalia et al. [5] and Newkome et al. [6] presented the first papers dealing with dendrimers. A multitude of dendrimers have been presented in the literature ranging from polyami-doamine [7,8],poly(propylene imine) [9,10], aromatic polyethers [11-13] and polyesters [14, 15], aUphatic polyethers [16] and polyesters [17], polyalkane [18-19], polyphenylene [20], polysilane [21] to phosphorus [22] dendrimers. Combinations of different monomers as well as architectural modifications have also been presented. For example, chirality has been incorporated in dendrimers [23,24]. Copolymers of linear blocks with dendrimer segments (dendrons) [25-27] and block-copolymers of different dendrons have been described [28]. 

Earlier we found that the addition of alkyl-modified poly(propylene imine) dendrimers to polypropylene leads to fibers which can be dyed in conventional acid or disperse dyeing processes [3]. The alkyl chains make the additive compatible with the polypropylene matrix, while the polar core of the dendrimer can act as a receptor for the dye molecules. This host-guest behavior is analogous to the principle of the dendritic box as described by Meijer et al. [30] and elaborated by Baars et al. for dye extraction processes [31]. 

This chapter describes composite materials composed of dendrimers and metals or semiconductors. Three types of dendrimer/metal-ion composites are discussed dendrimers containing structural metal ions, nonstructimal exterior metal ions, and nonstructiu al interior metal ions. Nonstructural interior metal ions can be reduced to yield dendrimer-encapsulated metal and semiconductor nanoparticles. These materials are the principal focus of this chapter. Poly(amidoamine) (PAMAM) and poly(propylene imine) dendrimers, which are the two commercially available families of dendrimers, are in many cases monodisperse in size. Accordingly, they have a generation-dependent munber of interior tertiary amines. These are able to complex a range of metal ions including Pd +, and Pt +. The maximmn munber... 

Fig. 24. Synthetic scheme for the introduction of metallic nanoparticles into perfluorinated polyether chain derivatized poly (propylene imine) PPI dendrimers. Reprinted with permission from Ref. 100 Copyright 2000 WUey-VCH...

Ulland B, et al Carcinogenicity of the industrial chemicals propylene imine and propane sultone. Nature 230 460-461, 1971... 

Reetz and Giebel 62) anchored sulfonylated poly(propylene imine) dendrimers by a cross-linking reaction with Sc(OTf)3, resulting in a non-porous material... 

Similarly, a poly( propylene imine) (PPl) dendrimer fitted with triethyleneoxy methyl ether and octyl groups at every terminal position was soluble in both organic and aqueous solvents, indicating sufficient structural flexibUity to present either the hydrophilic or hydrophobic termini toward the solvent (Fig. 11.8 Pan and Ford 1999, 2000). 

Figure 11.15 (a) The structure of an amphiphilic poly (propylene imine) dendrimer. (b)... 

Figure 11.19 (a) Structure of a hydrophilic fifth-generation poly(propylene imine) dendron containing a focal hydrophobic polystyrene block, (b) Structure of a fourth-generation r-buty-loxycarbonyl (Boc)-protected polylysine dendron having a focal poly(ethylene glycol) chain. 

Figure 11.39 Structures of poly(amido amine) (PAMAM) and poly (propylene imine) (PPI) dendrimers with peripheral aliphatic chains.

Figure 11.44 (Left) Structures of photoresponsive poly(propylene imine) dendrimers. (Right) The isomerization behavior of pahnitoyl-functionalized amphiphilic dendrimers at the water surface.

Su A, Tan S, Thapa P, Flanders BN, Ford WT. Highly ordered Langmuir-Blodgett films of amphiphilic poly(propylene imine) dendrimers. J Phys Chem C 2007 111 4695 -4701. 

Tsuda K, Dol GC, Gensch T, Hofkens J, Latterini L, Weener JW, MeijerEW, De SchryverEC. Fluorescence from azobenzene functionalized poly(propylene imine) dendrimers in self-assembled supramolecular structures. J Am Chem Soc 2000 122 3445-3452. 

Figure 13.6 The structure of the G(3)-poly(propylene imine) dendrimers.

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