Premium
Effective Tuning of Ketocyanine Derivatives through Acceptor Substitution
Author(s) -
Poe Ambata,
Della Pelle Andrea,
Byrnes Sean,
Thayumanavan S.
Publication year - 2015
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.201406625
Subject(s) - acceptor , cyanine , moiety , chemistry , aromaticity , carbon 13 nmr , photochemistry , stereochemistry , crystallography , molecule , organic chemistry , physics , fluorescence , condensed matter physics , quantum mechanics
A series of ketocyanine derivatives possessing bis(diarylamino)fluorenyl donors and variable acceptors installed at the bridging carbon atom were synthesized to investigate how the electronic structure of the dye can be systemically tuned through stabilization of the cyanine‐like character of the donor by increasing the acceptor strength. Analysis of the 1 H NMR spectra indicates that the “charge‐separated” species dominates in these dyes, given that carbons possessing a positive or negative charge in the resonance structures of this state purposefully shift downfield or upfield, respectively, depending on the strength of the acceptor moiety. In DAA‐Fl‐PI, the acceptor strength and the gain of acceptor aromaticity indicates a predisposition of the separated state, indicated by asymmetry in the 1 H NMR spectrum, as well as uneven distribution of the HOMO on the fluorenyl donor.