Ethylenediamine core poly dendrimer

Table I Selected Molecular Characteristics of Ethylenediamine Core Poly(amidoamine) (PAMAM) Dendrimers...

Table 2. Size measurements on poly(amidoamine)PAMAM dendrimers (ethylenediamine core) from computer analysis of TEM images...

Three representative dendrimers, with different numbers of generations, are shown in Fig. 3.7-7. They are a poly(amidoamine) dendrimer (PAMAM) synthesized by D.A. Tomalia, which incorporates an ethylenediamine core and terminal amino groups (Fig. 3.7-7a), a poly(propyleneamine) product (POPAM) reported by... 

Fig. 11 Dendritic branching mathematics for predicting the number of dendrimer surface groups, number of branch cells, and molecular weight. Calculated values are for [ethylenediamine core] lieniiri-poly(amidoamine) series with nanoscale diameters...

Poly(amidoamine) dendrimers such as 91, which differ only in the presence of an ethylenediamine (instead of ammonia) core, were used to host the electron transfer reaetion between photoexcited polycyelic aromatic hydrocarbons (PAHs) and ni-tromethane [169]. Quenching studies in aqueous solution indicate that the PAHs associate with the dendrimer, residing in the interior region, far from the charged surface. It was also found that within the dendrimer structure, nitromethane quenches alternant PAHs, while nonalternant PAHs are not quenched. This selective behavior of nitromethane parallels that commonly observed in solution, while in the presence of traditional micelles both classes of PAHs are quenched by nitromethane. 

The poly(imine) dendrimers form a special type of polymer. The dendrimers have different physical properties from linear polymers, and some have been used for biomedical applications. Dendrimers typically start with a core molecule. Ammonia can be used for this purpose. In the presence of methanol, ammonia reacts with methyl acrylate forming N(CH2CH2COOCH3)3. The resulting molecule can react further with ethylenediamine or other diamines forming N(CH2CH2CONHCH2CH2NH2)3- At the end of each branch is a free amino group that can react with two methyl acrylate monomers and further with two ethylenediamine molecules. The continuation of the process leads to a dendrimer (polyamidoamine or PAMAM) [2]. A different dendrimer is poly(propylene imine), which has butylenediamine as a core molecule. 

Among the many different architectmes used for dendrimer construction, poly(amidoamine) (PAMAM) dendrimers are the most extensively used and characterized family [6]. PAMAM dendrimers are synthesized by the divergent approach. Starting from a multi-amine core such as ethylenediamine... 

Tomalia presented the synthesis of dendrimers as Starburst polymers, which consisted of poly(amide-amine)s as shown in Scheme 1 [2]. The core molecule in this case was ammonia, and the building block was methylacrylate. First, ammonia reacted with methylacrylate by a Michael-type addition. The obtained ester-terminated molecule was treated with a large excess amount of ethylene-diamine to form amino groups at the terminal positions (generation 0, GO). In this reaction, the methylester is the protected form of the amine, and the treatment with ethylenediamine (ester-amide transformation) corresponds to the deprotection of the ester function. Treatment of this amine-terminated molecule again with methylacrylate results in the formation of another terminal methyl-ester group. The molecule can be extended by repeating these operations. 

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