Poly(Phenylene-pyridyl) Dendrimers:  Synthesis and Templating of Metal Nanoparticles

Abstract

A new family of poly(phenylene-pyridyl) dendrimers (up to the fourth generation) with different periphery was synthesized via a divergent route by using a cascade of Diels-Alder cycloadditions. Tetra(4-ethynylphen-1-yl)methane served as a core. A new A 2B cyclopentadienone building block, namely, pyridine-containing cyclopentadienone with protected dienophile functions was prepared. By varying the building blocks at the last step of dendrimer construction, one could design molecules possessing either a phenyl-or a pyridyl-decorated outershell. The products were characterized by NMR spectroscopy, MALDI-TOF mass spectrometry, elemental analysis, atomic force microscopy, thermogravimetric analysis, DSC, and dynamic light scattering methods. These stiff polyphenylene dendrimers with pyridine embeds were then used as a matrix for encapsulation of Pd nanoparticles. The fourth-generation poly(phenylenepyridyl) dendrimer with a phenyl-decorated periphery and pyridine-containing interior was found to serve as a powerful template for metal nanoparticle formation, resulting in excellent nanoparticle stability (no precipitation was observed for more than 6 months).

Dendrimer/inorganic nanomaterial composites: Tailoring preparation, properties, functions, and applications of inorganic nanomaterials with dendritic architectures

“…In addition to PAMAM, dendrimers based on propyleneimine [28], ethyleneimine [29], diaminobutane [30] phosphorus-containing [31], and phenylene-pyridyl units [32] have been used to prepare dendrimer/noble metal nanoparticle composites. More recently, Astruc and coworkers developed an interesting family of dendrimers ( Figure 5) synthesized by click reaction and applied them as templates and hosting agents for Pd NPs [33,34].…”

Thermodynamic properties of pyridine-containing polyphenylene dendrimers of the first-fourth generations

“…15, 16 The structures of the studied samples were confirmed by the data of NMR spectroscopy, MALDI TOF mass spectrometer, and elemental analysis data. 15 The structures of dendrimers G1 8Py, G2 24Py, G3 42Py, and G4 90Py are presented above and below.…”

“…15 A BKT 3 completely automated adiabatic vacuum calorim eter designed and produced at the Termis joint stock closed com pany (Mendeleevo, Mosocow Region) was used for the study of the temperature dependence of heat capacity С p° = f(T) of the samples at 6-300 K. Liquid helium and nitrogen were used as cooling agent. Ampules with substances were filled with dry he lium (as a heat exchange gas) to a pressure of 4 kPa at room temperature.…”

Achievements in polycondensation and condensation polymers

“…matic dendrimers and their complexation with metals, DNA, drugs, and other compounds were investigated at length [247][248][249][250][251][252][253][254][255][256][257][258][259]. It was found that these com pounds show promise for many fields, for example, for the delivery of genes, the encapsulation of nanoparti cles by dendrimers, and the manufacture of dual action preparations.…”