TY - JOUR
T1 - Electronic interactions between π-stacked chromophores in nonsymmetric tertiary naphthyl Di- And polyarylureas
AU - Santos, Grace B.Delos
AU - Lewis, Frederick D.
PY - 2005/9/15
Y1 - 2005/9/15
N2 - The synthesis, structure, and spectroscopy of a family of tertiary di- and polyarylureas possessing a naphthyl and several different arene end groups separated by a variable number of internal phenylenediamine linking groups are reported. Molecular modeling and 1H NMR chemical shift data are consistent with the formation of compact, folded structures in which the arene groups adopt a splayed face-to-face geometry. The structure and solvent dependence of the electronic absorption and emission spectra have been determined and are interpreted with the aid of ZINDO calculations. The electronic absorption spectra are relatively insensitive to the choice of arene end group, the number of linking groups, and the solvent polarity. In contrast, the solution fluorescence is highly dependent upon the structure and solvent polarity. These observations are attributed to a small change in polarity upon excitation of the ground state to a naphthalene-localized Franck-Condon singlet state, which can undergo relaxation to a highly polar emissive state with extensive charge-transfer character.
AB - The synthesis, structure, and spectroscopy of a family of tertiary di- and polyarylureas possessing a naphthyl and several different arene end groups separated by a variable number of internal phenylenediamine linking groups are reported. Molecular modeling and 1H NMR chemical shift data are consistent with the formation of compact, folded structures in which the arene groups adopt a splayed face-to-face geometry. The structure and solvent dependence of the electronic absorption and emission spectra have been determined and are interpreted with the aid of ZINDO calculations. The electronic absorption spectra are relatively insensitive to the choice of arene end group, the number of linking groups, and the solvent polarity. In contrast, the solution fluorescence is highly dependent upon the structure and solvent polarity. These observations are attributed to a small change in polarity upon excitation of the ground state to a naphthalene-localized Franck-Condon singlet state, which can undergo relaxation to a highly polar emissive state with extensive charge-transfer character.
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U2 - 10.1021/jp052406+
DO - 10.1021/jp052406+
M3 - Article
C2 - 16834196
AN - SCOPUS:25444511402
SN - 1089-5639
VL - 109
SP - 8106
EP - 8112
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 36
ER -