Professeur des Universités, Sorbonne Université
Responsable du pôle de Chimie Physique et Biologique de la Matière Vivante
PASTEUR, Département de chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS
24 rue Lhomond, 75005 Paris, France
Email: Ludovic.Jullien@ens.psl.eu or Ludovic.Jullien@sorbonne-universite.fr
Phone: +33 144323333
Office: E142c
Home page: https://ludovicjullien.org/
Publications
1996 |
Multichromophoric cyclodextrins. 3. Investigation of dynamics of energy hopping by frequency-domain fluorometry Article de journal M N Berberan-Santos; J Canceill; E Gratton; L Jullien; J -M Lehn; P So; J Sutin; B Valeur Journal of Physical Chemistry, 100 (1), p. 15–20, 1996. @article{Berberan-Santos:1996, title = {Multichromophoric cyclodextrins. 3. Investigation of dynamics of energy hopping by frequency-domain fluorometry}, author = {M N Berberan-Santos and J Canceill and E Gratton and L Jullien and J -M Lehn and P So and J Sutin and B Valeur}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0003019274&doi=10.1021%2fjp951598d&partnerID=40&md5=99ebe5d1e0d18c77b7580fe2784de54a}, doi = {10.1021/jp951598d}, year = {1996}, date = {1996-01-01}, journal = {Journal of Physical Chemistry}, volume = {100}, number = {1}, pages = {15--20}, abstract = {A β-cyclodextrin labeled with seven naphthoyloxy chromophores was studied by steady-state and time-resolved fluorescence spectroscopy in order to get information on the dynamics of energy hopping between chromophores. The steady-state fluorescence anisotropy was recorded as a function of excitation wavelength in a mixture of methanol and ethanol at 110 K (rigid glass). The fluorescence anisotropy decay was obtained under the same conditions by the multifrequency phase-modulation technique upon excitation at 290 nm. The data were analyzed and interpreted on the basis of a theoretical model involving a unique rate constant for energy hopping between nearest neighbors. In particular, this model predicts a long-time leveling-off of the emission anisotropy at 1/7th of the fundamental anisotropy, which is confirmed by both steady-state and time-resolved data and thus indicates that there is no preferred mutual orientation between the chromophores. As regards the rate of energy hopping, an average value of 2 × 109 s-1 can be deduced from the comparison between the theoretical and experimental decays. This value is shown to be consistent with a dipole-dipole mechanism of energy transfer. © 1996 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A β-cyclodextrin labeled with seven naphthoyloxy chromophores was studied by steady-state and time-resolved fluorescence spectroscopy in order to get information on the dynamics of energy hopping between chromophores. The steady-state fluorescence anisotropy was recorded as a function of excitation wavelength in a mixture of methanol and ethanol at 110 K (rigid glass). The fluorescence anisotropy decay was obtained under the same conditions by the multifrequency phase-modulation technique upon excitation at 290 nm. The data were analyzed and interpreted on the basis of a theoretical model involving a unique rate constant for energy hopping between nearest neighbors. In particular, this model predicts a long-time leveling-off of the emission anisotropy at 1/7th of the fundamental anisotropy, which is confirmed by both steady-state and time-resolved data and thus indicates that there is no preferred mutual orientation between the chromophores. As regards the rate of energy hopping, an average value of 2 × 109 s-1 can be deduced from the comparison between the theoretical and experimental decays. This value is shown to be consistent with a dipole-dipole mechanism of energy transfer. © 1996 American Chemical Society. |
Multichromophoric cyclodextrins. 4. Light conversion by antenna effect Article de journal L Jullien; J Canceill; B Valeur; E Bardez; J -P Lefèvre; J -M Lehn; V Marchi-Artzner; R Pansu Journal of the American Chemical Society, 118 (23), p. 5432–5442, 1996. @article{Jullien:1996, title = {Multichromophoric cyclodextrins. 4. Light conversion by antenna effect}, author = {L Jullien and J Canceill and B Valeur and E Bardez and J -P Lef\`{e}vre and J -M Lehn and V Marchi-Artzner and R Pansu}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029953291&doi=10.1021%2fja954332t&partnerID=40&md5=86be6c0094475ed11e09091268977ba1}, doi = {10.1021/ja954332t}, year = {1996}, date = {1996-01-01}, journal = {Journal of the American Chemical Society}, volume = {118}, number = {23}, pages = {5432--5442}, abstract = {A water soluble β-cyclodextrin (CD-NA) bearing seven naphthoyl chromophores forms very stable 1:1 complexes with a merocyanine laser dye DCM-OH (4-(dicyanomethylene)-2-methyl-6-(p-(bis(hydroxyethyl)amino)-styryl)-4 H-pyran). The antenna effect, i.e. energy transfer from the naphthoyl antenna chromophores to the encased dye, is shown to occur with 100% efficiency. The stability of the complexes is very high (K(s) textasciitilde 105) owing to the contribution of the naphthoate residues. The structural features of the complexes have been examined in detail: circular dichroism experiments confirm the expected axial orientation of DCM-OH in the cavity of CD-NA, and fluorescence anisotropy measurements together with 13C-NMR longitudinal relaxation time measurements show that the complex formed between CD-NA and DCM-OH is tight. The mechanisms of homotransfer (i.e., between naphthoate chromophores) and heterotransfer (i.e., from naphthoate chromophores to DCM-OH included in the cavity) are discussed in light of existing theories. In both cases, the major contribution arises more likely from Coulombic interaction than from short-range interactions. Such multichromophoric cyclodextrins are good models for mimicry of the antenna function in photosynthesis and show great promise as photochemical microreactors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A water soluble β-cyclodextrin (CD-NA) bearing seven naphthoyl chromophores forms very stable 1:1 complexes with a merocyanine laser dye DCM-OH (4-(dicyanomethylene)-2-methyl-6-(p-(bis(hydroxyethyl)amino)-styryl)-4 H-pyran). The antenna effect, i.e. energy transfer from the naphthoyl antenna chromophores to the encased dye, is shown to occur with 100% efficiency. The stability of the complexes is very high (K(s) textasciitilde 105) owing to the contribution of the naphthoate residues. The structural features of the complexes have been examined in detail: circular dichroism experiments confirm the expected axial orientation of DCM-OH in the cavity of CD-NA, and fluorescence anisotropy measurements together with 13C-NMR longitudinal relaxation time measurements show that the complex formed between CD-NA and DCM-OH is tight. The mechanisms of homotransfer (i.e., between naphthoate chromophores) and heterotransfer (i.e., from naphthoate chromophores to DCM-OH included in the cavity) are discussed in light of existing theories. In both cases, the major contribution arises more likely from Coulombic interaction than from short-range interactions. Such multichromophoric cyclodextrins are good models for mimicry of the antenna function in photosynthesis and show great promise as photochemical microreactors. |
1995 |
Drug delivery: Piercing vesicles by their adsorption onto a porous medium Article de journal M -A Guedeau-Boudeville; L Jullien; J -M Di Meglio Proceedings of the National Academy of Sciences of the United States of America, 92 (21), p. 9590–9592, 1995. @article{Guedeau-Boudeville:1995, title = {Drug delivery: Piercing vesicles by their adsorption onto a porous medium}, author = {M -A Guedeau-Boudeville and L Jullien and J -M Di Meglio}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028820145&doi=10.1073%2fpnas.92.21.9590&partnerID=40&md5=251b948d8859e06857263108f1f5e581}, doi = {10.1073/pnas.92.21.9590}, year = {1995}, date = {1995-01-01}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {92}, number = {21}, pages = {9590--9592}, abstract = {Experimental evidence is presented that supports the possibility of building a 'molecular drill.' By the adsorption of a vesicle onto a porous substrate (specifically, a lycopode grain), it was possible to increase the permeability of the vesicle by locally stretching its membrane. Molecules contained within the vesicle, which could not cross the membrane, were delivered to the porous substrate upon adsorption. This general process could provide another method for drug delivery and targeting.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Experimental evidence is presented that supports the possibility of building a 'molecular drill.' By the adsorption of a vesicle onto a porous substrate (specifically, a lycopode grain), it was possible to increase the permeability of the vesicle by locally stretching its membrane. Molecules contained within the vesicle, which could not cross the membrane, were delivered to the porous substrate upon adsorption. This general process could provide another method for drug delivery and targeting. |
Formation of highly stable heterodimers in aqueous solution between β-cyclodextrin derivatives bearing multiple opposite charges Article de journal B Hamelin; L Jullien; F Guillo; J -M Lehn; A Jardy; L De Robertis; H Driguez Journal of Physical Chemistry, 99 (51), p. 17877–17885, 1995. @article{Hamelin:1995, title = {Formation of highly stable heterodimers in aqueous solution between β-cyclodextrin derivatives bearing multiple opposite charges}, author = {B Hamelin and L Jullien and F Guillo and J -M Lehn and A Jardy and L De Robertis and H Driguez}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0000285072&partnerID=40&md5=34255c509ef04ce2b93b4a7f1cf9684a}, year = {1995}, date = {1995-01-01}, journal = {Journal of Physical Chemistry}, volume = {99}, number = {51}, pages = {17877--17885}, abstract = {Two water-soluble perfunctionalized β-cyclodextrins bearing amino or carboxyl groups were used to examine the possibility of obtaining stable heterodimers in water. The acidobasic properties of both compounds may be accounted for on the basis of a theoretical interpretation of the potentiometric titration of polyelectrolytes. The association constants between positively and negatively charged β-cyclodextrins were determined by potentiometric titrations. The Gibbs energies of association between cyclodextrins are shown to depend on the product of elementary charges borne by each interacting species. The results obtained are significant for evaluation of electrostatic contributions to molecular recognition. © 1995 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two water-soluble perfunctionalized β-cyclodextrins bearing amino or carboxyl groups were used to examine the possibility of obtaining stable heterodimers in water. The acidobasic properties of both compounds may be accounted for on the basis of a theoretical interpretation of the potentiometric titration of polyelectrolytes. The association constants between positively and negatively charged β-cyclodextrins were determined by potentiometric titrations. The Gibbs energies of association between cyclodextrins are shown to depend on the product of elementary charges borne by each interacting species. The results obtained are significant for evaluation of electrostatic contributions to molecular recognition. © 1995 American Chemical Society. |