Steady-state and time-resolved spectroscopic studies of photodynamic sensitizers: Porphyrins and phthalocyanines

1988 ◽  
Vol 10 (3) ◽  
pp. 241-268 ◽  
Author(s):  
Elena Reddi ◽  
Giulio Jori
Keyword(s):  
Steady State ◽  
Spectroscopic Studies ◽  
Time Resolved

Organic Triplet Excited States of Gold(I) Complexes with Oligo(o- orm-phenyleneethynylene) Ligands: Conjunction of Steady-State and Time-Resolved Spectroscopic Studies on Exciton Delocalization and Emission Pathways

2011 ◽  
Vol 133 (35) ◽  
pp. 14120-14135 ◽  
Author(s):  
Wei Lu ◽  
Wai-Ming Kwok ◽  
Chensheng Ma ◽  
Chris Tsz-Leung Chan ◽  
Ming-Xin Zhu ◽  
...  
Keyword(s):  
Steady State ◽  
Excited States ◽  
Spectroscopic Studies ◽  
Time Resolved ◽  
Triplet Excited States

Dramatic luminescence signal from a Co(ii)-based metal–organic compound due to the construction of charge-transfer bands with Al3+ and Fe3+ ions in water: steady-state and time-resolved spectroscopic studies

2020 ◽  
Vol 44 (11) ◽  
pp. 4376-4385 ◽  
Author(s):  
Pooja Daga ◽  
Prakash Majee ◽  
Debal Kanti Singha ◽  
Priyanka Manna ◽  
Sayani Hui ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Steady State ◽  
Organic Compound ◽  
Spectroscopic Studies ◽  
Charge Transfer Complexes ◽  
Time Resolved ◽  
Luminescence Signal ◽  
Turn On ◽  
Metal Organic

A Co(ii)-based metal–organic compound exhibits luminescence turn-on by Al3+ and quenching by Fe3+ due to the formation of charge-transfer complexes/adducts.

Time-resolved and Steady-state Fluorescence Spectroscopic Studies of the Human Lens with Comparison to Argpyrimidine, Pentosidine and 3-OH-kynurenine¶

2007 ◽  
Vol 76 (5) ◽  
pp. 549-554 ◽  
Author(s):  
Line Kessel ◽  
Stanislav Kalinin ◽  
Ram H. Nagaraj ◽  
Michael Larsen ◽  
Lennart B.-Å. Johansson
Keyword(s):  
Steady State ◽  
Spectroscopic Studies ◽  
Human Lens ◽  
Time Resolved ◽  
Steady State Fluorescence

Time-resolved spectroscopic studies of the photochemistry of some diphenylgermylene (Ph2Ge:) precursors

2005 ◽  
Vol 83 (9) ◽  
pp. 1324-1338 ◽  
Author(s):  
Cameron R Harrington ◽  
William J Leigh ◽  
Bryan K Chan ◽  
Peter P Gaspar ◽  
Dong Zhou
Keyword(s):  
Steady State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Spectral Characteristics ◽  
Complex Mixture ◽  
Laser Flash ◽  
Spectroscopic Studies ◽  
Major Product ◽  
High Yield ◽  
Time Resolved

The photochemistry of diphenylbis(trimethylsilyl)germane (2a) and 1,4-dihydro-5-methyl-1,2,3,4,9,9-hexaphenyl-1,4-germanonaphthalene (11) has been studied in solution by steady-state and laser flash photolysis methods with a view to detecting the transient germylene derivative diphenylgermylene (Ph2Ge), which has previously been shown to be the major product of photolysis of 2a and a closely related derivative of 11. Steady-state trapping experiments confirm the formation of Ph2Ge as the major germanium containing primary product in both cases; with 2a, the results indicate that other transient species are also formed in minor yields, including phenyl(trimethylsilyl)germylene (Ph(TMS)Ge, ca. 6%) and diphenyl(trimethylsilyl)germyl radicals (Ph2(TMS)Ge, ≥15%). Laser flash photolysis of 2a in deoxy genated hexane solution yields a complex mixture of overlapping transient absorptions, which is shown to be comprised of Ph2Ge, tetraphenyldigermene (15) and its oligomerization products, and another species with spectral characteristics similar to the Ph2(TMS)Ge radical. The latter has been independently generated by hydrogen abstraction from diphenyl(trimethylsilyl)germane by tert-butoxyl radicals. Compound 11 extrudes Ph2Ge more cleanly and efficiently upon photolysis in solution, yet laser flash photolysis affords excited triplet and triplet-derived species as the only detectable transient products; interpretation of the results for this compound is made difficult by its slow thermal decomposition to 5-methyl-1,2,3,4-tetraphenylnaphthalene. It is concluded that in spite of the fact that both 2a and 11 afford Ph2Ge in high yield upon photolysis, they are poor precursors for study of the species in solution by time-resolved UV–vis methods, owing to the formation of other, more strongly absorbing transient products than Ph2Ge, whose lowest energy absorption is characteristically weak.Key words: germylene, germyl radical, flash photolysis, disilylgermane, photochemistry.

Steady-state and Time-resolved Spectroscopic Studies of Benzanilides

1999 ◽  
Vol 54 (8-9) ◽  
pp. 495-502 ◽  
Author(s):  
Józef Heldt ◽  
Janina R. Heldt ◽  
Jerzy Kamiński
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Steady State ◽  
Proton Transfer ◽  
Room Temperature ◽  
Spectroscopic Studies ◽  
Fluorescence Band ◽  
Polar Solvents ◽  
Time Resolved ◽  
Decay Times

Steady-state and time-resolved spectroscopic studies of benzanilide (I) and jV-methylbenzanilide (II)were performed at 298 and 77 K in various solvents. The results indicate that benzanilide fluorescencein non-polar solvents at room temperature involves three independent modes of emission: F1 (LE) normalfluorescence from the initially excited state S1 (LE) with λmax = 320 nm, F2´(PT) fluorescence from the proton transfer tautomer with λmax = 468 nm, F2″CT) fluorescence from the species where intramolecular charge transfer appears, with λmax = 510 nm. At 77 K in MCH a new fluorescence band, Fag, appears at λmax=415 nm instead of the F2(PT) and F2″CT) fluorescence. This new emission originates from benzanilide dipolar aggregates or cis-imidol dimers. The decay times of these emission modes aredifferent.N-methylbenzanilide, dissolved in nonpopular and weakly polar solvents at room temperature and at77 K, shows only two fluorescence modes, i.e., the normal and the charge-transfer emissions at 320 nmand 520 nm, respectively. The fluorescence is deactivated with two decay times, 30 ps and 2.05 ns, inMCH solution.

Steady-State and Time-Resolved Fluorescence Spectroscopic Studies on Interaction of the N-terminal Region with the Hairpin Loop of the Phytocystain Scb

2008 ◽  
Vol 19 (4) ◽  
pp. 631-639 ◽  
Author(s):  
Keiko Doi-Kawano ◽  
Etsuko Nishimoto ◽  
Yoshiaki Kouzuma ◽  
Daisuke Takahashi ◽  
Shoji Yamashita ◽  
...  
Keyword(s):  
Steady State ◽  
Spectroscopic Studies ◽  
Terminal Region ◽  
Hairpin Loop ◽  
Time Resolved Fluorescence ◽  
Time Resolved
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