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Surprising Properties of a Furo‐Furanone
Author(s) -
Calzaferri Gion,
Brühwiler Dominik,
Meng Tao,
Dieu LeQuyenh,
Malinovskii Vladimir L.,
Häner Robert
Publication year - 2010
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.201000728
Subject(s) - molecule , dipole , absorption (acoustics) , intermolecular force , excitation , chemistry , spectral line , absorption spectroscopy , fluorescence , aggregate (composite) , transition dipole moment , anisotropy , monomer , j aggregate , chemical physics , crystallography , photochemistry , materials science , nanotechnology , polymer , organic chemistry , physics , composite material , optics , quantum mechanics , astronomy
The electronic absorption, fluorescence, and excitation spectra of furo[3,4‐ c ]furanone ( 1 ) have been measured in different solvents at different concentrations. We observed a complex dependence of absorption and excitation spectra as a function of the concentration in CH 2 Cl 2 and THF due to aggregate formation. Interestingly, the fluorescence spectra were not affected. Resolving the puzzle was made possible by the fact that 1 fits perfectly into the channels of zeolite L (ZL) microcrystals to form 1 –ZL guest–host composites. The geometry of the ZL channel system ensures a well‐defined orientation of the embedded dye molecules, thereby leading to a preferred orientation of their electronic transition dipole moment (ETDM) and thus to objects with pronounced optical anisotropy properties. This enabled us to understand that in solution the monomers that are present at low concentration form an aggregate in which the molecules sit on top of each other and arrange into a J‐type aggregate configuration at higher concentrations. The signature of the latter is observed in the 1 –ZL composites. This seems to be the first example in which the insertion of molecules into a nanochannel microcrystal has helped in understanding the weak intermolecular interactions that take place in solution.