Synthesis of a water-soluble block copolymer of 2-isopropenylnaphthalene and methacrylic acid bearing a pyrene group1
Introduction
There have been a number of studies utilizing fluorescence techniques to investigate electronic energy transfer or migration in polymer chains1, 2, 3, 4. One particular type of experiments requires that each polymer molecule should contain complementary fluorescent and fluorescence-quenching groups in its opposing terminal ends.
Guillet and coworkers5, 6, 7, however, have reported the possibility of using energy transfer in man-made polymers to mimic similar effects in natural chloroplasts and photosynthesis in plants. Hence, it seems appropriate to investigate water-soluble polymers which are useful as analogues that can assist in developing and understanding the behavior of biological macromolecules, and may provide a practical profitable approach to this concept.
In previous work[8]we described the synthesis of water-soluble polymers, in particular poly(methacrylic-acid) containing naphthyl and pyrenyl groups at opposite ends of the chain. The main object of the work reported here is the preparation and characterization of a water-soluble block copolymer of 2-IPN-MAA bearing a pyrene group at one end of the polymer chains; such a structure is represented below.
Section snippets
Experimental
All experiments were carried out in glass reaction vessels which had been flamed out under high vacuum before use. Ultra-violet absorption spectra were recorded on a Cary 14 spectrometer. NMR spectra were recorded on Perkin Elmer 360 MHZ instrument, using 10% w/v solutions. Steady-state fluorescence spectra of very dilute polymer solutions in water (10−6 M) were recorded on a Jacso J-0077 spectrophotometer. An excitation wavelength of 290 nm was used to excite naphthalene chromophores.
Results and discussion
2-IPN is known to polymerize anionically10, 11; accordingly, we use this character to synthesis a block copolymer of 2-IPN and MAA (polymer I), which we anticipate to contain a short segment of 2-IPN. This was achieved anionically by means of an indirect method using the pre-reacted mixture of Sec-butyllithium and 2-IPN in the (mol/mol) ratio 1:10 for trimethylsilyl methacrylate polymerization and subsequently terminating the living polyanions with 1-bromomethylpyrene. Methanolysis of the
Conclusion
A block copolymer of 2-isopropenylnaphthalene and methacrylic acid bearing a pyrene group has been synthesized. Spectroscopic and fluorescence studies demonstrate the presence of the naphthalene units and pyrene group. Evidence of energy-transfer between these groups has been obtained.
More photophysical investigations are required to assess the importance of this copolymer in relation to man-made or biological macromolecules.
References (15)
- et al.
Polymer
(1984) - et al.
Macromolecules
(1990) - et al.
Macromolecules
(1982) - et al.
Macromolecules
(1992) - et al.
Macromolecules
(1982) - et al.
Macromolecules
(1985) - et al.
Macromolecules
(1986)
Cited by (3)
Pyrene florescence to study polymeric systems
2005, Molecular Interfacial Phenomena of Polymers and BiopolymersIsopropylnaphthalenes - A potential feedstock for oxidation processes
2003, Przemysl ChemicznyAnionic polymerization of 2-vinylnaphthalene
2000, American Chemical Society, Polymer Preprints, Division of Polymer Chemistry
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This work is dedicated to Professor A. D. Jenkins and Dr D. R. M. Walton as gratitude for their supervision during my study at Sussex University, England.