Chelation-Induced Quenching of Two-Photon Absorption of Azacrown Ether Substituted Distyryl Benzene for Metal Ion Sensing
2014 (English)In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 10, no 2, 778-788 p.Article in journal (Refereed) Published
Imaging of metal ion concentration, distribution, and dynamics can pave the way to diagnose a number of diseases and to identify the normal functioning of the human body. Recently, two-photon microscopy-based imaging of metal ions has become popular due to several favorable factors as compared to fluorescence-based imaging. However, much has to be investigated in order to design probes with large two-photon absorption cross sections and yet with selective binding affinity toward metal ions. In particular, it is crucial to recognize the mechanisms of metal ion-induced changes of the two-photon absorption intensity. The present paper contributes to this effort and reports on the results of extensive studies carried out to define a reliable computational protocol that can account for sampling, solvent, and finite temperature,effects for one- and two-photon properties of metal probes, using azacrown ether substituted distyrylbenzene embedded in solvents as a testbed. We employ a selection of theoretical approaches to model the structure of the probe alone and in the presence of Mg2+ ion in acetonitrile solvent, including static quantum-chemical calculations, rigid- and flexible-body molecular dynamics, and hybrid QM/MM molecular dynamics. For a set of solute-solvent configurations, the one- and the two-photon properties are computed using the recently developed polarizable embedding response approach. It is found that the hybrid QM/MM molecular dynamics based approach is the most successful one among other employed computational strategies, viz, reproduction of the metal ion-induced blue shift in the absorption wavelength and decrease in the two-photon absorption cross section, which actually is in excellent agreement with experimental data. The mechanism for such metal ion-induced changes in the optical properties is put forward using a few-state model. Possible design principles to tune the two-photon absorption properties of probes are also discussed.
Place, publisher, year, edition, pages
2014. Vol. 10, no 2, 778-788 p.
Molecular-Dynamics Simulations, Bond-Length Alternation, Cross-Sections, Charge-Transfer, Excited-State, Density, Systems, Chromophores, Transition, Alignment
Other Chemistry Topics
IdentifiersURN: urn:nbn:se:kth:diva-143450DOI: 10.1021/ct400924uISI: 000331342400030ScopusID: 2-s2.0-84894167925OAI: oai:DiVA.org:kth-143450DiVA: diva2:707589
QC 201403252014-03-252014-03-212014-03-25Bibliographically approved