Dynamics of ion-regulated photoinduced electron transfer in BODIPY-BAPTA conjugates.
نویسندگان
چکیده
Efficient Ca(2+)-switched fluorescent sensors, where fluorescence output is governed by a light-activated ion-gated electron transfer pathway, can be obtained on combining BODIPY chromophores with a readily oxidized biocompatible and selective BAPTA receptor. Herein we report the synthesis and studies of two such conjugates, which vary in the nature of the spacer separating the two electroactive components, namely none (1) or phenyl (2). Single crystal X-ray crystallography and molecular modelling structures and calculations give information on molecular and electronic structure, while steady-state fluorescence experiments show high Ca(2+)-induced fluorescence enhancement factors of 122 and 23 and K(d) values of 0.50 μM and 0.13 μM for 1 and 2, respectively. Notably, studies of the ultrafast photoinduced processes (through transient absorption spectroscopy) give access to electron transfer dynamics in pseudo-physiological media as well as in a polar non-protic solvent and information about the fate of the excited molecules in the presence and absence of calcium. In water, electron transfer rates as high as 3.3 × 10(12) s(−1) and 8.3 × 10(11) s(−1) are measured for the ion-free, directly connected conjugate and the variant incorporating a phenyl spacer, respectively. This electron transfer pathway is efficiently blocked by the presence of an ion, restoring fluorescence.
منابع مشابه
Photoinduced electron transfer of zinc porphyrin electrostatically bound to DNA
Cationic zinc porphyrin, ZnTMAP4+, externally binds to calf thymus DNA or polynucleotides through electrostatic interactions in a self-stacked (for DNA or [poly(dA-dT)]2) or unstacked (for [poly(dG-dC)]2) form at low [porphyrin]/[base-pair] ratios. When ZnTMAP4+ in these conjugates was excited in the presence of a cationic electron acceptor, electron transfer (ET) occurred to produce the radica...
متن کاملChemically regulating Rh(I)-Bodipy photoredox switches.
The ability of Rh(I) centers to undergo photoinduced electron transfer from discrete metal orbitals to Bodipy fluorophores is mediated through reversible coordination chemistry.
متن کاملFast responding and selective near-IR Bodipy dye for hydrogen sulfide sensing.
A Bodipy based, highly selective probe for hydrogen sulfide has been designed, synthesized and demonstrated to detect H2S in living cells. In this design, the reduction of two arylazido groups change the charge transfer characteristics of the 3,5-distyryl substituents on the Bodipy core, producing a 20 nm bathochromic spectral shift in the absorption band, and quenching of the emission by 85% c...
متن کاملPhenothiazine-BODIPY-fullerene triads as photosynthetic reaction center models: substitution and solvent polarity effects on photoinduced charge separation and recombination.
Novel photosynthetic reaction center model compounds of the type donor2 -donor1 -acceptor, composed of phenothiazine, BF2 -chelated dipyrromethene (BODIPY), and fullerene, respectively, have been newly synthesized using multistep synthetic methods. X-ray structures of three of the phenothiazine-BODIPY intermediate compounds have been solved to visualize the substitution effect caused by the phe...
متن کاملDynamics of Bimolecular Photoinduced Electron-Transfer Reactions
From the accumulated results of several research groups over the last 25 years, it is clear that photoinduced electron-transfer reactions have significantly broadened the scope of organic photochemistry.1 The fundamental mechanistic principle is that when quenching of an excited state via electron transfer is sufficiently exothermic, the reaction occurs at or close to the diffusion-controlled l...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology
دوره 11 11 شماره
صفحات -
تاریخ انتشار 2012