Synthesis of pyrene end‐capped A6 dendrimer and star polymer with phosphazene core via “click chemistry”

Abstract

Novel hexa‐armed and pyrene (Pyr) end‐capped phosphazene dendrimer [N3P3‐(Pyr)6] and star polymer with poly(ε‐caprolactone) (PCL) arms [N3P3‐(PCL‐Pyr)6] were prepared via two series of reactions. In these series, core‐first approach was used starting from a hexa‐hydroxy functional phosphazene derivative (N3P3‐(OH)6). It was used as an initiator in the ring‐opening polymerization of ε‐caprolactone to prepare a hexa‐armed PCL star polymer (N3P3‐(PCL‐OH)6). Hydroxyl functionalities of N3P3‐(OH)6 and N3P3‐(PCL‐OH)6 were then successfully converted into bromide and azide, in turn. Further end‐group modifications of azide functional dendrimer precursor (N3P3‐(N3)6) and star polymer (N3P3‐(PCL‐N3)6) were achieved quantitatively via the Cu(I) catalyzed click reaction between azide functional groups and 1‐ethynyl pyrene in the final step. Moreover, the pyrene end‐capped phosphazene dendrimer and star polymer were used in noncovalent functionalization of multiwalled carbon nanotubes. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Synthesis, characterization, and Pb2+ ion sensing application of hexa‐armed dansyl end‐capped poly(ε‐caprolactone) star polymer with phosphazene core

“…29 He and coworkers reported that dansyl-functional aminoquinoline derivative can be employed in ratiometric detection of Zn(II) cation. 32,33 They have less entanglement in the solid state, high solubility in various organic solvents, as well as lower solution and bulk viscosities compared to linear ones having similar molecular weights. 31 Star-shaped polymers having multiple arms joined at the central core have attracted the attention of scientists due to their unique shape and possible processing advantages resulting from their compact structure.…”

Synthesis, Characterization, and Ion Sensing Application of Pyrene‐Containing Chemical Probes

“…Click chemistry method was selected due to its versatility, reliability, and specificity even in heterogeneous reaction systems . Moreover, it hardly requires protection of functional groups, gives high reaction yields, and has exclusive selectivity for the 1,4‐triazole formation …”

“…Pyrene‐containing macromolecular structures have attracted a great deal of attention to be employed in fluorescent probes due to their long fluorescence lifetime and a well‐defined fluorescence spectrum, which is sensitive to the polarity of the environment . There are numerous studies in the literature on the fluorescence sensor applications of pyrene‐containing molecular compounds and high‐molecular polymers toward various analytes, including nitroaromatic compounds, metal ions, anions, and glucose …”

Novel Coumarin Substituted Water Soluble Cyclophosphazenes as “Turn-Off” Type Fluorescence Chemosensors for Detection of Fe3+ ions in Aqueous Media

“…When BR^is the halogen, it can be replaced with ease by alkoxy, aryloxy or amino groups via nucleophilic substitution reactions [1][2][3][4][5][6]. Hexachlorocyclotriphosphazene, trimer, N 3 P 3 Cl 6 , (1) or octachlorocyclotetraphosphazene, tetramer, N 4 P 4 Cl 8 (2) namely cyclophosphazenes are a kind of phosphazene compounds that they show many special characteristics.…”