Tomalia

The synthesis and study of dendrimers is a relatively new branch of macro-molecular chemistry. It began in 1985 with the publication of two landmark papers (D.A. Tomalia, H. Baker, J. Dewald, J.M. Hall, G. Kallos, R. Martin and J. Ryder, Polym. J., 1985,17,117-132 and G.R. Newkome, Z. Yao, G.R. Baker and V.K. Gupta, J. Org. Chem., 1985, 50, 2003-2004), and has grown to become a very vibrant research field. The word dendrimer comes from the Greek word dendra, meaning tree, and was applied to these compounds by Tomalia et al. in their very first paper. Newkome s team, by contrast, called their molecules arborols from the Latin word arbor, which also means a tree. The term cascade molecule has also been used, but the word dendrimer is the one that is used most widely throughout the literature, and is also used in the present chapter. 

Tomalia, D.A. et al. Dendritic macromolecules—Synthesis of starburst dendrimers, Macromolecules, 19, 2466-2468, 1986. 

JMJ Frechet, DA Tomalia (2001) Dendrimers and other Dendritic Polymers. Wiley, Chichester, UK. GR Newkome, CN Moorefield, F VBgtle (2001) Dendrimers and Dendrons. Wiley-VCH,Weinheim, Germany. 

J. M. J. Frechet and D. A. Tomalia, (Eds.) Dendrimers and Other Dendritic Polymers, Wiley, West Sussex, England, 2001. 

Tomalia, D.A. Genealogically Directed Synthesis Starbust/Cascade Dendrimers and Hyperbranched Structures. 165, (1993). 

With this method new dendrimers were prepared in the following years by Denkewalter et al. [22], Tomalia et al. [23], Newkome et al. [24], and ourselves [25]. Following a reaction pathway similar to the one used in 1978, Meijer et al. successfully synthesized a polynitrile dendrimer 14 up to the fifth generation on a large scale [26] (Fig. 8). 

Tomalia DA, Baker H, Dewald J, Hall M, Kallos G, Martin S, RoeckJ, Ryder J, Smith P (1985) PolymJ 17 117... 

The addition of ammonia to excess methyl acrylate (a linear monomer), followed by amidation with excess ethylenediamine afforded the resultant cascade molecule, and thus Tomalia [37] created the commercially available PAMAM starburst series of dendrimers (2, Fig. 2). Related core molecules such as ethylenediamine and aminoalcohols and other functionalizable groups such as thiol moieties were used to prepare similar dendrimers [38]. This methodology is applicable to most primary amines, resulting in a 1 —> 2 branching pattern. Recently, examples of related Si-, [39] P-, [40] and metallo systems [41], which follow this linear monomer protocol have been reported. 

Fig. 2a-c. Dendrimer synthesis using linear building blocks a Vogtle s original procedure b DSM s commercial process c Tomalia s synthesis of PAMAM dendrimers... 

Host-guest systems made from dendritic materials have potential in the areas of membrane transport and drug delivery [68, 84, 85]. In a recent report [136] Tomalia and coworkers investigated structural aspects of a series of PAM AM bolaamphiphiles (e.g., 50) with a hydrophobic diamino do decane core unit. Fluorescence emission of added dye (nile red) was significantly enhanced in an aqueous medium in the presence of 50 unlike the cases when 51 and 52 were added (Fig. 23). Addition of anion surfactants to this mixture generated supramolecular assemblies which enhanced their ability (ca.by 10-fold) to accommodate nile red (53). Further increase in emission was noted by decreasing the pH from the normal value of 11 for PAMAM dendrimers to 7. At lower pH values the... 

Tabakovic I, Miller LL, Duan RG,Tully DC, Tomalia DA (1997) Chem Mater 9 736... 

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