Abstract
Two regioisomeric D1-A-D-A-D1 type π-conjugated molecules (1,4-bis{5-[4-(5-fluoro-7-(5-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole)]thiophen-2-yl}-2,5-bis(hexyldecyloxy)benzene (Prox-FBT) and 1,4-bis{5-[4-(6-fluoro-7-(5-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole)]thiophen-2-yl}-2,5-bis(hexyldecyloxy)benzene (Dis-FBT)) are synthesized, by controlling the fluorine topology to be proximal or distal relative to the central core. The different F geometries are confirmed by the 1H–1H nuclear Overhauer effect spectroscopy (NOESY). Clearly different optical, electrochemical, and thermal transition behaviors are obtained, i.e., stronger absorption, deeper valance band (by ≈0.2 eV), and higher melting/recrystallization temperatures (by 7–20 °C) are observed for Dis-FBT. The different intermolecular packing and unit cell structures are also calculated for the two regioisomers, based on the powder X-ray diffraction and 2D grazing-incidence wide-angle X-ray diffraction measurements. A tighter π–π packing with a preferential monoclinic face-on orientation is extracted for Dis-FBT, compared to Prox-FBT with bimodal orientations. Different topological structures significantly affect the electrical and photovoltaic properties, where Prox-FBT shows higher parallel hole mobility (2.3 × 10−3 cm2 V−1 s−1), but Dis-FBT demonstrates higher power conversion efficiency (5.47%) with a larger open-circuit voltage of 0.95 V (vs 0.79 V for Prox-FBT). The findings suggest that small changes in the topological geometry can affect the electronic structure as well as self-assembly behaviors, which can possibly be utilized for fine-adjusting the electrical properties and further optimization of optoelectronic devices.
| Original language | English |
|---|---|
| Article number | 1701942 |
| Journal | Advanced Functional Materials |
| Volume | 27 |
| Issue number | 33 |
| DOIs | |
| Publication status | Published - 2017 Sep 6 |
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Keywords
- fluorine
- optoelectronics
- packing
- regioisomers
- topology
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Condensed Matter Physics
- Electrochemistry
Cite this
Two Regioisomeric π-Conjugated Small Molecules : Synthesis, Photophysical, Packing, and Optoelectronic Properties. / Li, Yuxiang; Lee, Dae Hee; Lee, Joungphil; Nguyen, Thanh Luan; Hwang, Sungu; Park, Moon Jeong; Choi, Dong Hoon; Woo, Han Young.
In: Advanced Functional Materials, Vol. 27, No. 33, 1701942, 06.09.2017.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Two Regioisomeric π-Conjugated Small Molecules
T2 - Synthesis, Photophysical, Packing, and Optoelectronic Properties
AU - Li, Yuxiang
AU - Lee, Dae Hee
AU - Lee, Joungphil
AU - Nguyen, Thanh Luan
AU - Hwang, Sungu
AU - Park, Moon Jeong
AU - Choi, Dong Hoon
AU - Woo, Han Young
PY - 2017/9/6
Y1 - 2017/9/6
N2 - Two regioisomeric D1-A-D-A-D1 type π-conjugated molecules (1,4-bis{5-[4-(5-fluoro-7-(5-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole)]thiophen-2-yl}-2,5-bis(hexyldecyloxy)benzene (Prox-FBT) and 1,4-bis{5-[4-(6-fluoro-7-(5-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole)]thiophen-2-yl}-2,5-bis(hexyldecyloxy)benzene (Dis-FBT)) are synthesized, by controlling the fluorine topology to be proximal or distal relative to the central core. The different F geometries are confirmed by the 1H–1H nuclear Overhauer effect spectroscopy (NOESY). Clearly different optical, electrochemical, and thermal transition behaviors are obtained, i.e., stronger absorption, deeper valance band (by ≈0.2 eV), and higher melting/recrystallization temperatures (by 7–20 °C) are observed for Dis-FBT. The different intermolecular packing and unit cell structures are also calculated for the two regioisomers, based on the powder X-ray diffraction and 2D grazing-incidence wide-angle X-ray diffraction measurements. A tighter π–π packing with a preferential monoclinic face-on orientation is extracted for Dis-FBT, compared to Prox-FBT with bimodal orientations. Different topological structures significantly affect the electrical and photovoltaic properties, where Prox-FBT shows higher parallel hole mobility (2.3 × 10−3 cm2 V−1 s−1), but Dis-FBT demonstrates higher power conversion efficiency (5.47%) with a larger open-circuit voltage of 0.95 V (vs 0.79 V for Prox-FBT). The findings suggest that small changes in the topological geometry can affect the electronic structure as well as self-assembly behaviors, which can possibly be utilized for fine-adjusting the electrical properties and further optimization of optoelectronic devices.
AB - Two regioisomeric D1-A-D-A-D1 type π-conjugated molecules (1,4-bis{5-[4-(5-fluoro-7-(5-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole)]thiophen-2-yl}-2,5-bis(hexyldecyloxy)benzene (Prox-FBT) and 1,4-bis{5-[4-(6-fluoro-7-(5-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole)]thiophen-2-yl}-2,5-bis(hexyldecyloxy)benzene (Dis-FBT)) are synthesized, by controlling the fluorine topology to be proximal or distal relative to the central core. The different F geometries are confirmed by the 1H–1H nuclear Overhauer effect spectroscopy (NOESY). Clearly different optical, electrochemical, and thermal transition behaviors are obtained, i.e., stronger absorption, deeper valance band (by ≈0.2 eV), and higher melting/recrystallization temperatures (by 7–20 °C) are observed for Dis-FBT. The different intermolecular packing and unit cell structures are also calculated for the two regioisomers, based on the powder X-ray diffraction and 2D grazing-incidence wide-angle X-ray diffraction measurements. A tighter π–π packing with a preferential monoclinic face-on orientation is extracted for Dis-FBT, compared to Prox-FBT with bimodal orientations. Different topological structures significantly affect the electrical and photovoltaic properties, where Prox-FBT shows higher parallel hole mobility (2.3 × 10−3 cm2 V−1 s−1), but Dis-FBT demonstrates higher power conversion efficiency (5.47%) with a larger open-circuit voltage of 0.95 V (vs 0.79 V for Prox-FBT). The findings suggest that small changes in the topological geometry can affect the electronic structure as well as self-assembly behaviors, which can possibly be utilized for fine-adjusting the electrical properties and further optimization of optoelectronic devices.
KW - fluorine
KW - optoelectronics
KW - packing
KW - regioisomers
KW - topology
UR - http://www.scopus.com/inward/record.url?scp=85024114148&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85024114148&partnerID=8YFLogxK
U2 - 10.1002/adfm.201701942
DO - 10.1002/adfm.201701942
M3 - Article
AN - SCOPUS:85024114148
VL - 27
JO - Advanced Functional Materials
JF - Advanced Functional Materials
SN - 1616-301X
IS - 33
M1 - 1701942
ER -