Premium
Intramolecular Excimer Formation of Poly(γ‐(1‐naphthylmethyl)‐ L ‐glutamate)
Author(s) -
Itagaki Hideyuki,
Sugiura Kouji,
Sato Hiyori
Publication year - 2001
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 - 10.1002/1521-3935(20010101)202:1<90::aid-macp90>3.0.co;2-h
Subject(s) - intramolecular force , chemistry , excimer , tetrahydrofuran , singlet state , circular dichroism , fluorescence , polymerization , photochemistry , polymer chemistry , polymer , crystallography , stereochemistry , organic chemistry , excited state , optics , physics , solvent , nuclear physics
Poly(γ(1‐naphthylmethyl)‐ L ‐glutamate) (PNLG) was synthesized and fractionated into samples with narrow molecular weight distributions. Absolute molecular weights of all the PNLGs used in this study were determined by time‐of‐flight matrix‐assisted laser desorption ionization mass spectrometry. The circular dichroism measurements of PNLG showed that all the PNLGs with a degree of polymerization larger than 7 had a right‐handed helical structure in tetrahydrofuran (THF) solution. The effects of molecular weight on the photostationary and transient fluorescence of PNLG were examined in order to obtain information on excimer formation and singlet energy migration. Because the structure of a PNLG is rigid and regular, a one‐dimensional random walk model can be used to describe singlet energy migration among side‐chain naphthyl groups of PNLG. Consequently, the singlet energy migration coefficient of PNLG in THF was found to be higher than 1.6×10 –5 cm 2 /s.