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Synthesis of a Polyphenol with a Mesoionic 6‐Oxo‐1,6‐dihydropyrimidin‐3‐ium‐4‐olate as Pendant Group and Its Photochemical Behavior
Author(s) -
Tonami Hiroyuki,
Uyama Hiroshi,
Kobayashi Shiro,
Menges Bernhard,
Mittler Silvia,
Theis Alexander,
Ritter Helmut
Publication year - 2003
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200390076
Subject(s) - mesoionic , moiety , chemistry , photochemistry , irradiation , polymer , monomer , polymer chemistry , polymerization , spectroscopy , organic chemistry , physics , nuclear physics , quantum mechanics
This study deals with the synthesis of a polyphenol bearing photosensitive groups, and its photochemical behavior upon UV irradiation. Mesoionic 5‐(4‐hydroxybenzyl)‐6‐oxo‐1,2,3‐triphenyl‐1,6‐dihydropyrimidin‐3‐ium‐4‐olate was prepared by condensation of 4‐benzyloxybenzylmalonic acid with N , N ′‐diphenylbenzamidine using dicyclohexylcarbodiimide as condensing agent, followed by deprotection of the benzyl group. The monomer was polymerized by an iron‐salen complex to give a polymer with a mesoionic 6‐oxo‐1,6‐dihydropyrimidin‐3‐ium‐4‐olate moiety as the pendant group. Spin coated polymer films were prepared and characterized. It was shown by IR spectroscopy that irradiation with UV light converted the mesoionic structure to a bis( β ‐lactam) structure. Waveguide spectroscopy showed a large decrease in the film thickness without refractive index changes during irradiation.Time development of the refractive index and the film thickness measured with p‐polarized light.