TY - JOUR
T1 - Luminescence Spectroscopy of Rhodamine Homodimer Dications in Vacuo Reveals Strong Dye-Dye Interactions
AU - Kjaer, Christina
AU - Lissau, Henriette
AU - Gravesen Salinas, Nina Katharina
AU - Østergaard Madsen, Andreas
AU - Stockett, Mark H.
AU - Storm, Freja E.
AU - Holm Hansen, Thomas
AU - Andersen, Jens Ulrik
AU - Laursen, Bo W.
AU - Mikkelsen, Kurt V.
AU - Brøndsted Nielsen, Mogens
AU - Brøndsted Nielsen, Steen
PY - 2019/2/18
Y1 - 2019/2/18
N2 - Being alone or together makes a difference for the photophysics of dyes but for ionic dyes it is difficult to quantify the interactions due to solvent screening and nearby counter ions. Gas-phase luminescence experiments are desirable and now possible based on recent developments in mass spectrometry. Here we present results on tailor-made rhodamine homodimers where two dye cations are separated by methylene linkers, (CH 2 ) n . In solution the fluorescence is almost identical to that from the monomer whereas the emission from bare cation dimers redshifts with decreasing n. In the absence of screening, the electric field from the charge on one dye is strong enough to polarize the other dye, both in the ground state and in the excited state. An electrostatic model based on symmetric dye responses (equal induced-dipole moments in ground state) captures the underlying physics and demonstrates interaction even at large distances. Our results have possible implications for gas-phase Förster Resonance Energy Transfer.
AB - Being alone or together makes a difference for the photophysics of dyes but for ionic dyes it is difficult to quantify the interactions due to solvent screening and nearby counter ions. Gas-phase luminescence experiments are desirable and now possible based on recent developments in mass spectrometry. Here we present results on tailor-made rhodamine homodimers where two dye cations are separated by methylene linkers, (CH 2 ) n . In solution the fluorescence is almost identical to that from the monomer whereas the emission from bare cation dimers redshifts with decreasing n. In the absence of screening, the electric field from the charge on one dye is strong enough to polarize the other dye, both in the ground state and in the excited state. An electrostatic model based on symmetric dye responses (equal induced-dipole moments in ground state) captures the underlying physics and demonstrates interaction even at large distances. Our results have possible implications for gas-phase Förster Resonance Energy Transfer.
U2 - 10.1002/cphc.201800933
DO - 10.1002/cphc.201800933
M3 - Journal article
C2 - 30576051
SN - 1439-4235
VL - 20
SP - 533
EP - 537
JO - ChemPhysChem
JF - ChemPhysChem
IS - 4
ER -