scholarly journals Femtosecond excited state dynamics of stilbene–viologen complexes with a weakly pronounced charge transfer

2020 ◽  
Vol 19 (9) ◽  
pp. 1189-1200
Author(s):  
Mikhail V. Rusalov ◽  
Valery V. Volchkov ◽  
Vladimir L. Ivanov ◽  
Mikhail Ya. Melnikov ◽  
Fedor E. Gostev ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
Photoinduced Electron Transfer ◽  
Charge Transfer Complexes ◽  
Excited State Dynamics

Charge transfer complexes between bis(18-crown-6)stilbene and viologen analogues. A femtosecond study of photoinduced electron transfer.

scholarly journals Femtosecond excited state dynamics of a stilbene–viologen charge transfer complex assembled via host–guest interaction

2017 ◽  
Vol 16 (12) ◽  
pp. 1801-1811 ◽  
Author(s):  
Mikhail V. Rusalov ◽  
Valery V. Volchkov ◽  
Vladimir L. Ivanov ◽  
Mikhail Ya. Melnikov ◽  
Ivan V. Shelaev ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
Photoinduced Electron Transfer ◽  
Charge Transfer Complex ◽  
Excited State Dynamics

The ultrafast photoinduced electron transfer in a supramolecular charge transfer complex was studied.

Control of reaction course of the excited state of charge-transfer complexes by the free energy of backward electron transfer

1998 ◽  
pp. 2093-2094 ◽  
Author(s):  
Naoki Haga ◽  
Hiroaki Takayanagi ◽  
Katsumi Tokumaru
Keyword(s):  
Electron Transfer ◽  
Free Energy ◽  
Excited State ◽  
Charge Transfer ◽  
State Of Charge ◽  
Charge Transfer Complexes

1,3,5-Triarylpyrazolines — pH-driven off-on-off molecular logic devices based on a “receptor1-fluorophore-spacer-receptor2” format with internal charge transfer (ICT) and photoinduced electron transfer (PET) mechanisms

2015 ◽  
Vol 93 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Ramon Zammit ◽  
Maria Pappova ◽  
Esther Zammit ◽  
John Gabarretta ◽  
David C. Magri
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
Photoinduced Electron Transfer ◽  
Photophysical Properties ◽  
Molecular Probes ◽  
Quantum Yields ◽  
Ph Sensing ◽  
Internal Charge Transfer ◽  
Internal Charge

The excited state photophysical properties of the 1,3,5-triarylpyrazolines 1–4 were studied in methanol and 1:1 (v/v) methanol–water, as well as 1:4 (v/v) methanol–water and water by fluorescence spectroscopy. The molecules 2–4 incorporate a “receptor1-fluorophore-spacer-receptor2” format while 1 is a reference compound based on a “fluorophore-receptor1” design. The molecular probes operate according to photoinduced electron transfer (PET) and internal charge transfer (ICT) processes. At basic and neutral pHs, 2–4 are essentially nonfluorescent due to PET from the electron-donating dimethylamino moiety appended on the 5-phenyl ring to the excited state of the 1,3,5-triarylpyrazoline fluorophore. At proton concentrations of 10−3 mol/L, the dimethylamino unit is protonated resulting in a strong blue fluorescence about 460 nm with significant quantum yields up to 0.54. At acid concentrations above 10−2 mol/L, fluorescence quenching is observed by an ICT mechanism due to protonation of the pyrazoline chromophore. Symmetrical off-on-off fluorescence–pH profiles are observed, spanning six log units with a narrow on window within three pH units. Hence, 2–4 are novel examples of ternary photonic pH sensing molecular devices.

Charge-transfer complexes of metal dithiolenes. IX. Photoinduced electron transfer within metal dithiolene-viologen ion pairs studied by flash photolysis

1992 ◽  
Vol 96 (25) ◽  
pp. 10323-10326 ◽  
Author(s):  
Horst Kisch ◽  
Walter Duemler ◽  
Claudio Chiorboli ◽  
Franco Scandola ◽  
Josef Salbeck ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Photoinduced Electron Transfer ◽  
Flash Photolysis ◽  
Ion Pairs ◽  
Charge Transfer Complexes ◽  
Metal Dithiolenes

Charge transfer emissive singlet excited states and photoinduced electron transfer properties in the diarylideneacetone compounds (RCHCH)2CO; R = phenyl, 1- and 2-naphthyl, 3-(N-ethylcarbazoyl), and 4-(C5H5)Fe(C5H4C6H4CHCH(CO)CHCHC6H5)

1990 ◽  
Vol 68 (12) ◽  
pp. 2278-2288 ◽  
Author(s):  
Pierre D. Harvey ◽  
Liangbing Gan ◽  
Christiane Aubry
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
Excited States ◽  
Photoinduced Electron Transfer ◽  
Flash Photolysis ◽  
Reduction Process ◽  
Transfer Reactions ◽  
Electron Transfer Reactions ◽  
Electron Reduction

Four diarylideneacetone compounds ((RCHCH)2CO, where the aryl groups are phenyl (dba), 1-naphthyl (1-dNapha), 2-naphthyl (2-dNapha), and 3-(N-ethylcarbazoyl) (dNECa)), and 4-(C5H5)Fe(C5H4C6H4CHCH(CO)CHCH(C6H5) (dba-Fc) have been prepared and characterized. The compounds are found to be fluorescent and photochemically and reversibly electrochemically active. The lowest-energy absorption bands for the diarylideneacetones are assigned to a charge transfer (CT) electronic transition, except for dba-Fc, in which a ferrocenyl ligand field transition assignment is made. The 77 K CT absorption and fluorescence bands are vibrationally structured (vibrational spacings = 1260–1360 cm−1). While the fluorescence decay at 293 K is monoexponential, the excited state fluorescence lifetimes (τF) for the 77 K samples exhibit double exponential decays, the short component being 0.38–0.64 ns and the long one 3.5–10.9 ns. The photophysical results are interpreted in terms of excited state deactivation processes dominated by radiationless pathways that are associated with the presence of fluorescent species with different geometries. Only the dNECa compound is found to be fluorescent in solution at 298 K [Formula: see text]. Cyclic voltammetry and coulometry measurements suggest that a reversible one-electron reduction process and an irreversible higher potential one-electron reduction process take place in the −1 to −2 V vs. SSCE range. In addition, dba-Fc also exhibits an electrochemically reversible one-electron oxidation wave at 0.52 V vs. SSCE centered at the ferrocenyl group. These results together with the spectroscopic electronic data have permitted evaluation of the reduction potentials of the lowest singlet (CT excited states (E1−/*);they range from 1.4 to 2.2 V vs. SSCE, with dba being the strongest photooxidizing agent and dNECa the weakest. Photoinduced intermolecular electron transfer reactions have been investigated by steady state fluorescence techniques and picosecond flash photolysis spectroscopy for dNECa and dba, respectively. The bimolecular deactivation rate constants, kq, for the reductive photoinduced electron transfer reactions of dNECa with diphenylamine (DPA) (kq = (2.65 ± 0.25) × 107 M−1 s−1) and N, N, N′, N′-tetramethylphenylenediamine (TMPM) (kq = (1.38 ± 0.03) × 108 M−1 s−1) have been obtained in THF solutions at 293 K. No fluorescence quenching is observed when oxidative and energy transfer quenchers are used with dNECa. For the non-emissive dba compound at room temperature, picosecond flash photolysis experiments show that quenching of the broad dba transient band (~500 nm) does indeed occur between 5 and 10 ns. Keywords: dibenzylideneacetone, charge transfer, photoelectron transfer.

Photoinduced electron transfer and charge resonance band in ion-pair charge-transfer complexes of styrylpyridinium tetraphenylborate

1995 ◽  
Vol 71 (1-3) ◽  
pp. 2069-2070 ◽  
Author(s):  
T. Nagamura ◽  
H. Kawai ◽  
T. Ichihara ◽  
H. Sakaguchi
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Photoinduced Electron Transfer ◽  
Ion Pair ◽  
Charge Transfer Complexes ◽  
Resonance Band

A Novel Fluorophore with Dual Fluorescence: Local Excited State and Photoinduced Electron-Transfer-Promoted Charge-Transfer State

ChemPhysChem ◽  
2004 ◽  
Vol 5 (8) ◽  
pp. 1200-1209 ◽  
Author(s):  
Viruthachalam Thiagarajan ◽  
Chellappan Selvaraju ◽  
E. J. Padma Malar ◽  
Perumal Ramamurthy
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
Photoinduced Electron Transfer ◽  
Charge Transfer State ◽  
Dual Fluorescence ◽  
Transfer State
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