TY - JOUR
T1 - Room-Temperature Pentacene Fluids
T2 - Oligoethylene Glycol Substituent-Controlled Morphologies and Singlet Fission
AU - Yoshino, Keisuke
AU - Sakai, Hayato
AU - Shoji, Yoshiaki
AU - Kajitani, Takashi
AU - Anetai, Hayato
AU - Akutagawa, Tomoyuki
AU - Fukushima, Takanori
AU - Tkachenko, Nikolai V.
AU - Hasobe, Taku
N1 - Funding Information:
This work was partially supported by JSPS KAKENHI grant numbers . JP17H05162, JP17H05270, JP18H01957, JP18K19063, JP20KK0120, and JP20H05234 to T.H. and no. JP17K14476, JP19H04592, and JP20K05652 to H.S. This work was partially performed under the Research Program of “Five-star Alliance” in “NJRC Mater. & Dev.” The synchrotron XRD experiments were performed at the BL44B2 beamline in SPring-8 with the approval of the RIKEN SPring-8 Center (proposal number 20170055).
Funding Information:
This work was partially supported by JSPS KAKENHI grant numbers . JP17H05162, JP17H05270, JP18H01957, JP18K19063, JP20KK0120, and JP20H05234 to T.H. and no. JP17K14476, JP19H04592, and JP20K05652 to H.S. This work was partially performed under the Research Program of ?Five-star Alliance? in ?NJRC Mater. & Dev.? The synchrotron XRD experiments were performed at the BL44B2 beamline in SPring-8 with the approval of the RIKEN SPring-8 Center (proposal number 20170055).
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/12/31
Y1 - 2020/12/31
N2 - We report the first synthesis of solvent-free pentacene fluids at room temperature together with observation of singlet fission (SF). Three pentacenes with different number of ethylene glycol (EG) side chains (n) were employed (denoted as (EG)n-Pc-(EG)n: n = 2, 3, and 4). The morphologies of these pentacenes largely depend on the lengths of EG chains (n). (EG)3-Pc-(EG)3 and (EG)4-Pc-(EG)4 indicate fluid compounds at room temperature, whereas (EG)2-Pc-(EG)2 is a solid compound. Microscopic clustering with short-range interactions between pentacene chromophores was confirmed in X-ray diffraction profiles of solvent-free fluids. Such a structural trend is an important origin of SF and consistent with the steady-state spectroscopic results. To one's surprise, femtosecond transient absorption spectroscopy demonstrated that SF occurred in thin films prepared from solvent-free fluids of (EG)3-Pc-(EG)3 and (EG)4-Pc-(EG)4 in spite of such excessive EG chains.
AB - We report the first synthesis of solvent-free pentacene fluids at room temperature together with observation of singlet fission (SF). Three pentacenes with different number of ethylene glycol (EG) side chains (n) were employed (denoted as (EG)n-Pc-(EG)n: n = 2, 3, and 4). The morphologies of these pentacenes largely depend on the lengths of EG chains (n). (EG)3-Pc-(EG)3 and (EG)4-Pc-(EG)4 indicate fluid compounds at room temperature, whereas (EG)2-Pc-(EG)2 is a solid compound. Microscopic clustering with short-range interactions between pentacene chromophores was confirmed in X-ray diffraction profiles of solvent-free fluids. Such a structural trend is an important origin of SF and consistent with the steady-state spectroscopic results. To one's surprise, femtosecond transient absorption spectroscopy demonstrated that SF occurred in thin films prepared from solvent-free fluids of (EG)3-Pc-(EG)3 and (EG)4-Pc-(EG)4 in spite of such excessive EG chains.
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U2 - 10.1021/acs.jpcb.0c09754
DO - 10.1021/acs.jpcb.0c09754
M3 - Article
C2 - 33336576
AN - SCOPUS:85098799608
SN - 1520-6106
VL - 124
SP - 11910
EP - 11918
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 52
ER -