Studies of the antenna effect in polymer molecules. 8. Photophysics of water-soluble copolymers of 1-naphthylmethyl methacrylate and acrylic acid

Guillet, J. E.; Rendall, W. A.

doi:10.1021/ma00155a035

Cited by 55 publications

(37 citation statements)

References 15 publications

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“…In an aqueous solution it is also likely the hydrophobic poly(acenaphthylene) block will collapse, further reducing interchromophore separations and thus enhancing the energy transfer efficiency. 6 The maximum of the coumarin emission in the pH 11 aqueous solution is red-shifted to 455 nm compared to 435 nm in dichloromethane, indicating a change in environment for the chromophore.…”

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confidence: 98%

Synthesis of Functionalized RAFT Agents for Light Harvesting Macromolecules

et al. 2004

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With the rapid development of nanotechnology, methodologies that will enable the cost-effective, controlled assembly of nanostructures in a routine manner are in high demand. Photoactive polymers are promising candidates to fulfill the materials requirements for energy storage and conversion devices, molecular sensors, and photonic materials. 1 Of particular interest is the utilization of efficient energy transfer processes in a polymer chain containing sequences of donor chromophores that absorb the incident light and the subsequent trapping of the energy in suitably placed acceptor species. 2 Such "antenna" polymers simulate the efficient light harvesting process of pigment arrays in the photosynthetic apparatus of green plants and can act to effectively increase the light absorption cross section of components in photomolecular devices.The synthesis of photoactive polymers with welldefined architectures has long been of great interest to photochemists but is difficult to achieve by conventional free radical polymerization methods. Living radical polymerization has made great progress in recent years and emerged as one of the most effective synthetic routes to make well-defined polymers. 3 Among them, reversible addition-fragmentation chain transfer (RAFT) polymerization appears particularly useful and, in principle, could be applied to all classical radical polymerization systems.The RAFT process involves performing a conventional free radical polymerization in the presence of certain thiocarbonylthio compounds SdC(Z)-SR that act as highly efficient reversible addition-fragmentation chain transfer agents and provide the polymerization with living characteristics. Following RAFT polymerization, nearly all polymer chains will have the thiocarbonylthio and R as end groups. RAFT polymerization thus provides a means of introducing specifically placed photoactive moieties into polymer chains using appropriately functionalized RAFT agents.We have previously incorporated chromophores into RAFT agents by the coupling reaction of 4-cyano-4-((thiobenzoyl)sulfanyl)pentanoic acid (RAFT-acid) with the required hydroxy-functionalized chromophores. 4 However, the stability of the resulting ester linkage can limit the applications in a number of circumstances, such as in the presence of acid or base. Although the ester linkage could be replaced by a more stable amide linkage, this general method is limited by the low yield of the coupling reaction between RAFT-acid and aminefunctionalized chromophores due to the competing aminolysis reaction of the thiocarbonylthio group by the amine.We describe here a novel alternative method to introduce suitable chromophores into a RAFT agent. The overall process and mechanism are outlined in Scheme 1. This procedure involves performing a RAFTlike polymerization reaction, except the molar ratio of monomer to RAFT agent is kept at unity. A small amount (1-2% molar equivalent) of free radical initiator is used to initiate the reaction. In our work 2-cyanoprop-2-yl dithiobenzoate 5 and 2,2′-az...

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confidence: 98%

Synthesis of Functionalized RAFT Agents for Light Harvesting Macromolecules

et al. 2004

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“…For example azo dyes were used as labels taking advantage of their trans-cis photoisomerization [203,217,260]. More frequently fluorescent labels have been fixed such as dansyl [174,175,177,287], naphthyl [211,259], anthracenyl [183,189] or pyrenyl groups [204,259]. For ESR studies, e.g.…”

Section: Functional Polysoapsmentioning

confidence: 99%

Molecular concepts, self-organisation and properties of polysoaps

Laschewsky

Polysoaps/Stabilizers/Nitrogen-15 NMR

223

126

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The article reviews water-soluble polymers characterized by surfactant side chains, and related amphiphilic polymers. Various synthetic approaches are presented, and rules for useful molecular architectures are given. Models for the self-organization of such polymers in water are presented comparing them with the micellization of low molecular weight surfactants. Highlighting key properties of aqueous polysoap solutions such as viscosity, surface tension and solubilization power, some structure-property relationships are established. Further, the formation of mesophases and of superstructures in bulk is addressed. Finally, the functionalization of polysoaps, and potential applications are discussed.

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“…Similar variations in both x and T~ were observed when determined from the A(R1IR2) and A(RzdR2,)." (See (9)(10)(11) in the preceding paper. )…”

Section: Introductionmentioning

confidence: 99%

Water-Soluble Copolymers. 53. Sodium-23 NMR Studies of Hydrophobically-Modified Polyacids: Copolymers of 2-(1-Naphthylacetamido)ethylacrylamide with Acrylic Acid and Methacrylic Acid

Newman¹,

McCormick²

1994

Macromolecules

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23Na NMR measurements of the longitudinal (R1) and transverse (R2) relaxation rates of copolymers of 1 % and 10 7% 2-(l-naphthylacetamido)ethylacrylamide (NAEAM) with acrylic acid (NAA-1 and NAA-10) and methacrylic acid (NMA-1 and NMA-10) have been performed as a function of the degree of ionization. The transverse relaxation was sufficiently biexponential at low a to extract R a and R z for NAA-10, NMA-1, and NMA-10. The correlations times, rC, and values of &x2, the product of the fraction of bound ions and the quadrapolar constant, were determined and indicate conformational transitions in NAA-10, NMA-1, and NMA-10. The incorporation of increasing concentration of hydrophobic NAEAM into the polyacids increases x at low degrees of ionization. The results of the relaxation studies are shown to be consistent with previous viscosity and fluorescence studies on the same systems.

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Studies of the antenna effect in polymer molecules. 8. Photophysics of water-soluble copolymers of 1-naphthylmethyl methacrylate and acrylic acid

Cited by 55 publications

References 15 publications

Synthesis of Functionalized RAFT Agents for Light Harvesting Macromolecules

Synthesis of Functionalized RAFT Agents for Light Harvesting Macromolecules

Molecular concepts, self-organisation and properties of polysoaps

Water-Soluble Copolymers. 53. Sodium-23 NMR Studies of Hydrophobically-Modified Polyacids: Copolymers of 2-(1-Naphthylacetamido)ethylacrylamide with Acrylic Acid and Methacrylic Acid

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