PMID- 30516769
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20181219
LR  - 20181219
IS  - 1463-9084 (Electronic)
IS  - 1463-9076 (Linking)
VI  - 21
IP  - 1
DP  - 2018 Dec 19
TI  - Exploring the ultrafast dynamics of a diarylethene derivative using sub-10 fs 
      laser pulses.
PG  - 192-204
LID - 10.1039/c8cp05882b [doi]
AB  - A diarylethene derivative, 
      1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)perfluorocyclopentene (DMP), is a 
      photoswitch molecule utilizing a reversible aromatic ring-opening reaction. The 
      quantum yield of the ring-opening reaction is however remarkably low. We 
      investigate the origin of this behaviour by means of ultrafast transient 
      absorption spectroscopy utilizing sub-10 fs pulses, which is an invaluable tool 
      for simultaneously studying both the electronic and the vibrational molecular 
      dynamics. Namely, a noncollinear optical parametric amplifier (NOPA) generating 
      sub-10 fs pulses in the spectral range 605-750 nm is employed. The transient 
      absorption signal is modulated by several vibrational modes, which are compared 
      with experimental and computational Raman spectra and then assigned to the ground 
      or excited electronic state. We observe that the most pronounced vibrational mode 
      - the ethylenic stretching mode at a frequency of 1501 cm-1 - exhibits 
      instantaneous frequency and amplitude modulation. The observed modulations occur 
      due to weak coupling with another 1431 cm-1 stretching mode mediated by a 
      vibrational mode of low frequency, i.e. around 60 cm-1. Fast internal conversion 
      S1 --> S0 originates in a relaxation through a conical intersection (found by 
      density-functional theory computations), facilitated by the two aforementioned 
      stretching modes.
FAU - Jarota, Arkadiusz
AU  - Jarota A
AD  - Institute of Applied Radiation Chemistry, Lodz University of Technology, ul. 
      Wroblewskiego 15, 93-590 Lodz, Poland. arkadiusz.jarota@p.lodz.pl.
FAU - Pastorczak, Ewa
AU  - Pastorczak E
FAU - Tawfik, Walid
AU  - Tawfik W
FAU - Xue, Bing
AU  - Xue B
FAU - Kania, Rafal
AU  - Kania R
FAU - Abramczyk, Halina
AU  - Abramczyk H
FAU - Kobayashi, Takayoshi
AU  - Kobayashi T
LA  - eng
PT  - Journal Article
PL  - England
TA  - Phys Chem Chem Phys
JT  - Physical chemistry chemical physics : PCCP
JID - 100888160
EDAT- 2018/12/06 06:00
MHDA- 2018/12/06 06:01
CRDT- 2018/12/06 06:00
PHST- 2018/12/06 06:00 [pubmed]
PHST- 2018/12/06 06:01 [medline]
PHST- 2018/12/06 06:00 [entrez]
AID - 10.1039/c8cp05882b [doi]
PST - ppublish
SO  - Phys Chem Chem Phys. 2018 Dec 19;21(1):192-204. doi: 10.1039/c8cp05882b.