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Synthesis, Characterization, and Application of Cationic Water‐Soluble Oligofluorenes in DNA‐Hybridization Detection
Author(s) -
Liu Bin,
Dishari Shudipto Konika
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200701906
Subject(s) - random hexamer , cationic polymerization , oligomer , quenching (fluorescence) , trimer , fluorescence , photochemistry , perylene , chemistry , förster resonance energy transfer , polymer chemistry , crystallography , dimer , molecule , organic chemistry , physics , quantum mechanics
A simple and efficient approach was developed for the synthesis of a series of cationic water‐soluble oligofluorenes up to a chain length of a heptamer. Bromoalkyl‐substituted fluorenyl boronic esters as the key intermediates were synthesized by using a modified Miyaura reaction. With an increasing number of repeat units (trimer to hexamer), the size‐specific oligomers have shown redshifts in both the absorption and emission maxima. The emission maximum reaches the limit for the hexamer in both water and buffer solution. The quantum yields of the oligomers decreased with increased oligomer size in water. Both fluorescence quenching of the oligomers by 9,10‐anthraquinone‐2,6‐disulfonate and the fluorescence resonance energy transfer experiments with the oligomers as the donor and fluorescein (Fl)‐labeled double‐stranded DNA (dsDNA‐Fl) as the acceptor revealed the chain‐length‐dependent behavior. The Stern–Volmer quenching constant increased with the molecular size, whereas the highest donor‐sensitized Fl emission was observed for the hexamer. These size‐specific oligomers also served as a model to study the structure–property relationships for cationic polyfluorenes.