Femtosecond transient absorption studies of electrons in liquid alkanes

1995 ◽  
Vol 99 (19) ◽  
pp. 7436-7438 ◽  
Author(s):  
Frederick H. Long ◽  
Hong Lu ◽  
Kenneth B. Eisenthal
Keyword(s):  
Transient Absorption ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies ◽  
Liquid Alkanes

scholarly journals Femtosecond Transient Absorption Studies of Two Novel Energetic Tetrazole Derivatives

2021 ◽  
pp. 100016
Author(s):  
Naga Krishnakanth Katturi ◽  
Chinmoy Biswas ◽  
Nagarjuna Kommu ◽  
Sai Santosh Kumar Raavi ◽  
Venugopal Rao Soma
Keyword(s):  
Transient Absorption ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies ◽  
Tetrazole Derivatives

Covalent decoration onto the outer walls of double walled carbon nanotubes with perylenediimides

2015 ◽  
Vol 3 (19) ◽  
pp. 4960-4969 ◽  
Author(s):  
Myriam Barrejón ◽  
Sara Pla ◽  
Isadora Berlanga ◽  
María J. Gómez-Escalonilla ◽  
Luis Martín-Gomis ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Charge Separation ◽  
Transient Absorption ◽  
Femtosecond Transient Absorption ◽  
Covalently Bonded ◽  
Absorption Studies ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Three new covalently bonded DWCNT–PDIs have been synthesized and characterized, showing exclusively functionalization of the outer walls leaving the inner walls intact. Femtosecond transient absorption studies were performed to seek evidence of charge separation in these hybrids.

Femtosecond Transient Absorption Studies of Energy Transfer within Chromophore-Labeled Dendrimers

2001 ◽  
Vol 105 (7) ◽  
pp. 1307-1312 ◽  
Author(s):  
Frederik V. R. Neuwahl ◽  
Roberto Righini ◽  
Alex Adronov ◽  
Patrick R. L. Malenfant ◽  
Jean M. J. Fréchet
Keyword(s):  
Energy Transfer ◽  
Transient Absorption ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies

Excited state electron transfer in A2 and A2B2 functionalized zinc porphyrins carrying rigid and flexible β-pyrrole π-extended substituents

2020 ◽  
Vol 24 (05n07) ◽  
pp. 904-919
Author(s):  
Michael B. Thomas ◽  
Siddhartha Kumar ◽  
Timothy Esquivel ◽  
Hong Wang ◽  
Francis D’Souza
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Transient Absorption ◽  
Binding Constants ◽  
Free Energy Calculations ◽  
Stable Complex ◽  
State Electron ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies ◽  
Zinc Porphyrins

Optical absorption and emission, electrochemical, and photochemical properties of peripherally functionalized with flexible and rigid [Formula: see text]-extended substituents on A2 and A2B2 type zinc porphyrins is investigated. The significance of rigid [Formula: see text]-substituents over flexible ones in governing the spectral properties is unraveled. Flexible [Formula: see text]-substituents on the porphyrin ring caused appreciable spectral broadening compared to porphyrin carrying rigid [Formula: see text]-substituents. Further, supramolecular dyads are formed by coordinating phenyl imidazole functionalized fullerene, C[Formula: see text]Im. The calculated binding constants for the 1:1 complexes is in the order of 2–7 × 105 M[Formula: see text] suggesting stable complex formation. Free-energy calculations performed according to the Rehm–Weller approach suggested possibility of excited state electron transfer in these dyads. Femtosecond transient absorption studies of the dyads performed in [Formula: see text]-dichlorobenzene showed evidence of occurrence of electron transfer from the singlet-excited state that was in competition with the intersystem crossing process to populate the triplet-excited state of porphyrins.

scholarly journals Ultralong UV/mechano-excited room temperature phosphorescence from purely organic cluster excitons

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xuepeng Zhang ◽  
Lili Du ◽  
Weijun Zhao ◽  
Zheng Zhao ◽  
Yu Xiong ◽  
...  
Keyword(s):  
Room Temperature ◽  
High Efficiency ◽  
Transient Absorption ◽  
Transient State ◽  
Exciton Model ◽  
Room Temperature Phosphorescence ◽  
Naphthalic Anhydride ◽  
Femtosecond Transient Absorption ◽  
Organic Solid ◽  
Absorption Studies

AbstractPurely organic room temperature phosphorescence (RTP) has attracted wide attention recently due to its various application potentials. However, ultralong RTP (URTP) with high efficiency is still rarely achieved. Herein, by dissolving 1,8-naphthalic anhydride in certain organic solid hosts, URTP with a lifetime of over 600 ms and overall quantum yield of over 20% is realized. Meanwhile, the URTP can also be achieved by mechanical excitation when the host is mechanoluminescent. Femtosecond transient absorption studies reveal that intersystem crossing of the host is accelerated substantially in the presence of a trace amount of 1,8-naphthalic anhydride. Accordingly, we propose that a cluster exciton spanning the host and guest forms as a transient state before the guest acts as an energy trap for the RTP state. The cluster exciton model proposed here is expected to help expand the varieties of purely organic URTP materials based on an advanced understanding of guest/host combinations.

scholarly journals Femtosecond Transient Absorption Studies of Simple Polyenes in Solution

1999 ◽  
Vol 19 (1-4) ◽  
pp. 371-374
Author(s):  
Kaoru Ohta ◽  
Yukito Naitoh ◽  
Keisuke Tominaga ◽  
Noboru Hirota ◽  
Keitaro Yoshihara
Keyword(s):  
Ground State ◽  
Vibrational Relaxation ◽  
Internal Conversion ◽  
Transient Absorption ◽  
Visible Region ◽  
Single Bond ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies ◽  
Bond Proceeds ◽  
Subnanosecond Time

We have conducted femtosecond transient absorption experiments on the excited-state dynamics of trans- and cis-hexatriene (HT) in solution. The transient absorption in the visible region decays with the time constant of about 500 fs, indicating that the internal conversion (IC) to the ground state occurs quite efficiently. The bleach recovery signal contains several time constants. The vibrational relaxation in the ground state occurs in 10–20ps and the slow relaxation process, which may be due to the conformational change around C—C single bond, proceeds in a subnanosecond time scale.

Femtosecond transient absorption studies on photochromism of dithienylethene derivates

1998 ◽  
Vol 76-77 ◽  
pp. 90-94 ◽  
Author(s):  
J. Ern ◽  
A.T. Bens ◽  
A. Bock ◽  
H.-D. Martin ◽  
C. Kryschi
Keyword(s):  
Transient Absorption ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies

scholarly journals Polariton Transitions in Femtosecond Transient Absorption Studies of Ultrastrong Light–Molecule Coupling

2020 ◽  
Vol 11 (7) ◽  
pp. 2667-2674 ◽  
Author(s):  
Courtney A. DelPo ◽  
Bryan Kudisch ◽  
Kyu Hyung Park ◽  
Saeed-Uz-Zaman Khan ◽  
Francesca Fassioli ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies

Synthesis and photochemical studies of a tris(4-iodophenoxy) subphthalocyaninato boron(III)-fulleropyrrolidine dyad

2016 ◽  
Vol 20 (08n11) ◽  
pp. 987-996 ◽  
Author(s):  
Robert Cantu ◽  
Habtom B. Gobeze ◽  
Francis D’Souza
Keyword(s):  
Charge Separation ◽  
Transient Absorption ◽  
Cycloaddition Reaction ◽  
Differential Pulse ◽  
Redox Potentials ◽  
Fluorescence Studies ◽  
Optical Absorbance ◽  
Femtosecond Transient Absorption ◽  
Donor And Acceptor ◽  
Absorption Studies

A subphthalocyanine-fullerene dyad, 1 was newly synthesized through axial functionalization via central boron of subphthalocyanine with [Formula: see text]-hydroxybenzaldehyde, and subsequent dipolar cycloaddition reaction of fullerene. The subphthalocyanine entity was peripherally functionalized with moderately electron rich 4-iodophenoxy substituents to probe their effect on photoinduced processes within the SubPc-C[Formula: see text] dyad. Optical absorbance studies revealed presence of both entities of the dyad while steady-state fluorescence studies revealed quenching of subphthalocyanine emission in the dyad in both nonpolar toluene and polar benzonitrile solvents. Further, redox potentials of the donor and acceptor entities were obtained by differential pulse voltammetry, and energy of different photochemical processes was evaluated. Femtosecond transient absorption studies revealed occurrence of charge separation in the SubPc-C[Formula: see text] dyad either from the 1SubPc* or 1C[Formula: see text]* in both nonpolar and polar solvents. That is, transient peaks in the 665 nm range corresponding to SubPc[Formula: see text] and at 1015 nm corresponding to C[Formula: see text] was possible to spectrally identify. The measured rate of charge separation, [Formula: see text] was found to be ∼7.0 × 10[Formula: see text] s[Formula: see text] irrespective of the solvent. The rate of charge recombination, [Formula: see text] from the decay of the C[Formula: see text] peak was found to be 1.1 × 109 s[Formula: see text] in toluene and 1.3 × 109 s[Formula: see text] in benzonitrile, respectively. The SubPc[Formula: see text]-C[Formula: see text] radical ion-pair populated the low-laying 3SubPc* prior returning to the ground state.

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