Dendrimer as building blocks

Figure 12.8 Procedure for using dendrimers as building blocks for multilayer films [28]...

Schenning APHJ, Elissen-Roman C, Weener J-W, Baars MWPL, Van der Gaast SJ, Meijer EW. Amphiphilic dendrimers as building blocks in supramolecular assemblies. J Am Chem Soc 1998 120 8199-8208. 

Watanabe S, Regen SL. 1994. Dendrimers as building blocks for multilayer construction. 

S. Watanabe, S.L. Regen, Dendrimers as Building Blocks for Multilayer Construction, Journal of the American Chemical Society 116, 8855. 

Some attention has arisen to consider dendrimers as building blocks for the construction of nanoarchitectures possessing higher complexity and dimensions beyond the dendrimer. In an early paper, Tomalia et al referred to their starburst polymers as a class of macromolecules obtained from the chemical bridging of starburst dendrimers. These macromolecules have been termed megamers, which have been defined as architectures derived from the combination of two or more dendritic macromolecules or poly(dendrimers). Many examples of randomly assembled as well as structure-controlled megamers have been reported, such as oligomeric covalent assemblies of dendrimers (i.e., dimers, trimers) referred... 

Watanabe, S. and Regen, S.L., Dendrimers as building-blocks for multilayer construction. J Amer Chem Soc, 1994. 116(19) p. 8855-8856. 

A dendrimer-based approach for the design of globular protein mimics using glutamic (Glu) and aspartic (Asp) acids as building blocks has been developed [151]. The preassembled Glu/Asp dendrones were attached to a 1,3-bifunctional adamantyl based on a convergent dendrimer synthesis strategy (see Fig. 28). 

Its design versatility, as generic dendrons may be prepared to be used later as building blocks in conjunction with other reactive molecules, or coupled to a multifunctional core to afford functional dendrimers, dendritic-linear hybrids, dendronized polymers, etc. This may be a particularly significant advantage if the coupled reactive or core molecule is itself sensitive to the reaction conditions used in the multiple steps of the iterative synthesis of a dendrimer. 

Due to the inherent stiffness of 1,4-phenylene based polymers and based on molecular modeUng calculations (see below), the question arises whether the shape of the dendrimer can be predetermined by choosing an appropriate core. This should be important for the use of dendrimers in single molecule appHca-tions, as carriers for dyes for single molecule optical spectroscopy or as building blocks for two- and three-dimensional assemblies. There are two possibiHties variation of the core and variation of the building unit. Therefore, we synthesized dendrimers based on cores with different symmetries presented in Scheme 4. 

An even more challenging approach covers polymeric X-ray contrast agents derived either from linear or from branched backbones, e.g. dendrimers. An overview on this field of research has been published recently [8]. Additionally, the reader is referred to the chapter in this book by Idee et al. covering novel dendrimers with triiodobenzenes as building blocks. 

By substituting either the metal (Os(II), Co(II)) or the ligand, (e.g., terpyridine tpy), a variety of metal complexes have been obtained and used as building blocks of dendrimers. As in the case of [Ru(bpy)3]2 +, the first oxidation process is metal centered and reductions are ligand centered. Metal complexes can be placed at the... 

An important field where the cyclopropanation reaction finds growing application is the construction of dendrimers possessing fullerenes either as functional cores [26-33] or branches [34-38]. Dendrimers can serve as building blocks for the construction of organized materials with nanosize precision due to the well-defined three-dimensional structure they possess. An issue of great importance is to incorporate photoactive and/or redox-active units at the center of the dendrimer in order to establish these types of materials as molecular devices. An example of an organofullerene material that has the potential to serve as a core building block for the construction of dendrimeric compounds... 

Newkome-type dendrons were attached to the carbon scaffold of SWCNTs and MWCNTs by defect group functionalization [108], First- and second-generation amine dendrons such as those depicted in Fig. 1.5 were condensed with the carboxyl groups of purified and opened SWCNTs and MWCNTs according to the car-bodiimide technique [108], These CNTderivatives can be expected to combine the characteristics of carbon nanotubes with those of dendrimers, potential building blocks for supramolecular, self-assembling and interphase systems. 

Tam, J. P. and Spetzler, J. C. (1995) Chemoselective approaches to the preparation of peptide dendrimers and branched artificial proteins using unprotected peptides as building blocks. Biomedical Peptides, Proteins Nucleic Acids 1, 123-132. 

Zhang LS, Tam JP (1997) Synthesis and application of unprotected cyclic peptides as building blocks for peptide dendrimers. J Am Chem Soc 119 2363-2370... 

Design and synthesis of hybrid polymers and of dendrimers for special applications and as building blocks for carbosilanes, polysilanes catalysis and highly crosslinked coatings. 

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