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
2015 ◽  
Vol 17 (20) ◽  
pp. 13387-13396 ◽  
Author(s):  
Saran Long ◽  
Meng Zhou ◽  
Kun Tang ◽  
Xiao-Li Zeng ◽  
Yingli Niu ◽  
...  

The red-shifted absorption of ApcE dimers results from extending chromophore conformation, which does not depend on strong exction coupling.


2021 ◽  
pp. 100016
Author(s):  
Naga Krishnakanth Katturi ◽  
Chinmoy Biswas ◽  
Nagarjuna Kommu ◽  
Sai Santosh Kumar Raavi ◽  
Venugopal Rao Soma

2015 ◽  
Vol 3 (19) ◽  
pp. 4960-4969 ◽  
Author(s):  
Myriam Barrejón ◽  
Sara Pla ◽  
Isadora Berlanga ◽  
María J. Gómez-Escalonilla ◽  
Luis Martín-Gomis ◽  
...  

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.


1995 ◽  
Vol 99 (19) ◽  
pp. 7436-7438 ◽  
Author(s):  
Frederick H. Long ◽  
Hong Lu ◽  
Kenneth B. Eisenthal

2020 ◽  
Vol 24 (05n07) ◽  
pp. 904-919
Author(s):  
Michael B. Thomas ◽  
Siddhartha Kumar ◽  
Timothy Esquivel ◽  
Hong Wang ◽  
Francis D’Souza

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.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xuepeng Zhang ◽  
Lili Du ◽  
Weijun Zhao ◽  
Zheng Zhao ◽  
Yu Xiong ◽  
...  

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.


1999 ◽  
Vol 19 (1-4) ◽  
pp. 371-374
Author(s):  
Kaoru Ohta ◽  
Yukito Naitoh ◽  
Keisuke Tominaga ◽  
Noboru Hirota ◽  
Keitaro Yoshihara

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.


2018 ◽  
Vol 20 (4) ◽  
pp. 2205-2210 ◽  
Author(s):  
Rui-Ling Zhang ◽  
Yang Yang ◽  
Song-Qiu Yang ◽  
Ke-Li Han

Ultrafast excited-state dynamic processes, charge and energy transfer in a HGCT system are unveiled by using femtosecond transient absorption spectroscopy.


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