The Convergent Route to Globular Dendritic Macromolecules: A Versatile Approach to Precisely Functionauzed Three-Dimensional Polymers and Novel Block Copolymers

Fréchet, Jean M. J.; Hawker, Craig J.; Wooley, Karen L.

doi:10.1080/10601329408545873

“…Many synthetic procedures have been presented for the synthesis of hyperbranched polymers, mostly by polycondensation reactions. , As a result of the high molecular and compositional heterogeneity, their structures could not be easily defined. In this Perspective, examples of several synthetic approaches will be demonstrated, mainly by anionic polymerization.…”

Section: Branched Polymersmentioning

confidence: 99%

50th Anniversary Perspective: Polymers with Complex Architectures

Polymeropoulos

¹

,

Ζάψας

²

,

Ντέτσικας

³

et al. 2017

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The scope of this Perspective is to highlight innovative contributions in the synthesis of well-defined complex macromolecular architectures and to emphasize the importance of these materials to polymer physical chemistry, physics, theory, and applications. In addition, this Perspective tries to enlighten the past and show possible pathways for the future. Among the plethora of polymerization methods, we briefly report the impact of the truly living and controlled/ living polymerization techniques focusing mainly on anionic polymerization, the mother of all living and controlled/living polymerizations. Through anionic polymerization well-defined model polymers with complex macromolecular architectures having the highest molecular weight, structural and compositional homogeneity can be achieved. The synthesized structures include star, comb/graft, cyclic, branched and hyberbranched, dendritic, and multiblock multicomponent polymers. In our opinion, in addition to the work needed on the synthesis, properties, and application of copolymers with more than three chemically different blocks and complex architecture, the polymer chemists in the future should follow closer the approaches Nature, the perfect chemist, uses to make functional complex macromolecular structures by noncovalent chemistry. Moreover, development of new analytical methods for the characterization/purification of polymers with complex macromolecular architectures is essential for the synthesis and properties study of this family of polymeric materials.

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“…Molecular catalysts, often in the form of metal ions complexed to a suitable ligand, can also be attached to dendrimer surfaces [3,9,10,93,94,96,148,149]. Such materials are generally structurally better defined than catalysts bounded to linear polymers, but like random-polymer catalysts they can be easily separated from reaction products.…”

Section: Dendrimer-encapsulated Metal Nanoclusters As Catalystsmentioning

confidence: 99%

Dendrimer-Encapsulated Metals and Semiconductors: Synthesis, Characterization, and Applications

Crooks

¹

,

Lemon

²

,

Sun

³

et al. 2000

Topics in Current Chemistry

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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, nonstructural exterior metal ions, and nonstructural 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 number of interior tertiary amines. These are able to complex a range of metal ions including Cu 2+ , Pd 2+ , and Pt 2+ . The maximum number of metal ions that can be sorbed within the dendrimer interior depends on the metal ion, the dendrimer type, and the dendrimer generation. For example, a generation six PAMAM dendrimer can contain up to 64 Cu 2+ ions. Nonstructural interior ions can be chemically reduced to yield dendrimer-encapsulated metal nanoparticles. Because each dendrimer contains a specific number of ions, the resulting metal nanoparticles are in many cases of nearly monodisperse size. Nanoparticles within dendrimers are stabilized by the dendrimer framework; that is, the dendrimer first acts as a molecular template to prepare the metal nanoparticles and then as a stabilizer to prevent agglomeration. These composites are useful for a range of catalytic applications including hydrogenations and Heck chemistry. The unique properties of the interior dendrimer microenvironment can result in formation of products not observed in the absence of the dendrimer. Moreover the exterior dendrimer branches act as a selective gate that controls access to the interior nanoparticle, which results in selective catalysis. In addition to single-metal nanoparticles, it is also possible to prepare bimetallic nanoclusters and dendrimer-encapsulated semiconductor nanoparticles, such as CdS, using this same general approach.

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“…The two main techniques for the synthesis of dendrimers with a unique combination of properties are the Starbust divergent method [4,5] and the convergent growth method [6], but a self-assembly method [7] has also been developed. In the divergent method, the dendrimer is started from the periphery (i.e.…”

Section: 2mentioning

confidence: 99%

Biocompatible Nanoparticulate Systems for Tumor Diagnosis and Therapy

Sadoqi

¹

,

Kumar

²

,

Lau‐Cam

³

et al. 2003

Nanotechnologies for the Life Sciences

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The sections in this article are Introduction Nanoscale Particulate Systems and their Building Blocks/Components Dendrimers Buckyballs and Buckytubes Quantum Dots Polymeric Micelles Liposomes Biodegradable Nanoparticles Preparation of Nanoparticles Biodegradable Optical Nanoparticles Optical Nanoparticles as a Potential Technology for Tumor Diagnosis Optical Nanoparticles as a Potential Technology for Tumor Treatment Optical Imaging and PDT Optical Imaging Fluorescence‐based Optical Imaging NIR Fluorescence Imaging NIR Dyes for Fluorescence Imaging PDT Basis of PDT Photosensitizers for PDT ICG : An Ideal Photoactive Agent for Tumor Diagnosis and Treatment Clinical Uses of ICG Structure and Physicochemical Properties of ICG Binding Properties of ICG Metabolism, Excretion and Pharmacokinetics of ICG Toxicity of ICG Tumor Imaging with ICG PDT with ICG Limitations of ICG for Tumor Diagnosis and Treatment Recent Approaches for Improving the Blood Circulation Time and Uptake of ICG by Tumors Recent Approaches for ICG Stabilization In Vitro PLGA ‐based Nanoparticulate Delivery System for ICG Rationale of Using a PLGA ‐based Nanoparticulate Delivery System for ICG In Vivo Pharmacokinetics of ICG Solutions and Nanoparticles Conclusions and Future Work

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The Convergent Route to Globular Dendritic Macromolecules: A Versatile Approach to Precisely Functionauzed Three-Dimensional Polymers and Novel Block Copolymers

Cited by 63 publications

References 48 publications

50th Anniversary Perspective: Polymers with Complex Architectures

50th Anniversary Perspective: Polymers with Complex Architectures

Dendrimer-Encapsulated Metals and Semiconductors: Synthesis, Characterization, and Applications

Biocompatible Nanoparticulate Systems for Tumor Diagnosis and Therapy

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