Photoregulation of Fluorescence in a Porphyrinic Dithienylethene Photochrome was written by Norsten, Tyler B.;Branda, Neil R.. And the article was included in Journal of the American Chemical Society in 2001.Reference of 57412-08-5 The following contents are mentioned in the article:
Synthesis and optical characterization was reported of a photochromic hybrid (I), where porphyrin macrocycles are attached to the ends of the 1,2-bis(3-thienyl)cyclopentene backbone. The relationship between the luminescence intensity of the porphyrins and the state of the photoswitch (open or closed) was clearly illustrated. The absorption spectrum of bis(porphyrin) I in the UV-vis region was essentially equivalent to the sum of the absorption spectra of the mol.’s components indicating that there was little change in the ground state of either chromophore upon covalent linking. Irradiation of I at 313 nm resulted in an immediate increase in the absorption intensity in the visible spectral region (500-625 nm) due to the appearance of the absorption bands of its closed isomer. After 4 min of continuous irradiation (2 x 10-4 M, toluene-d8), the photostationary state was reached and was identified by 1H NMR spectroscopy as consisting of 69% of the closed isomer. The ease at which this photochem. ring closure occurs was impressive in the light of the fact that porphyrins have been reported, on occasion, to inhibit photochromic processes. Irradiation of the closed isomer at ¦Ë >480 nm resulted in the rapid ring-opening photoreaction and e regeneration of the original absorption spectrum corresponding to I. Luminescence of the porphyrin macrocycles in I and its closed isomer greatly depended on the state of the 1,2-(dithienyl)cyclopentene photoswitch. In the open form it displayed significant fluorescence intensity at 655 nm when excited at 430 nm. When the photocyclization reaction was carried out by irradiating at 313 nm, the nonfluorescent closed form was produced. Back irradiation at ¦Ë >480 nm regenerated closed isomer I and restored the original emission spectrum. The intensity of the porphyrins fluorescence was conveniently regulated by toggling between open and closed isomers by alternate irradiation at 313 nm and >480 nm clearly demonstrating that I can act as a system for reversible data processing using fluorescence as the detection method. This study involved multiple reactions and reactants, such as 4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5Reference of 57412-08-5).
4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5) belongs to catalyst ligands. Attachment of the ligand to the metal may be through a single atom, in which case it is called a monodentate ligand, or through two or more atoms, in which case it is called a didentate or polydentate ligand. The ability of ligands to engender a variety of useful properties of organometallic complexes is the major enabling force for the discovery of new catalytic reactions, activation of small molecules, dramatically enhanced reactivity.Reference of 57412-08-5
Referemce:
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI