Research output: Contribution to journal › Article › peer-review
Impact of terminal substituents on the electronic, vibrational and optical properties of thiophene-phenylene co-oligomers. / Sosorev, Andrey Yu; Nuraliev, Muzaffar K.; Feldman, Elizaveta V. et al.
In: Physical Chemistry Chemical Physics, Vol. 21, No. 22, 05.06.2019, p. 11578-11588.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Impact of terminal substituents on the electronic, vibrational and optical properties of thiophene-phenylene co-oligomers
AU - Sosorev, Andrey Yu
AU - Nuraliev, Muzaffar K.
AU - Feldman, Elizaveta V.
AU - Maslennikov, Dmitry R.
AU - Borshchev, Oleg V.
AU - Skorotetcky, Maxim S.
AU - Surin, Nikolay M.
AU - Kazantsev, Maxim S.
AU - Ponomarenko, Sergei A.
AU - Paraschuk, Dmitry Yu
PY - 2019/6/5
Y1 - 2019/6/5
N2 - Owing to the combination of efficient charge transport and bright luminescence, thiophene-phenylene co-oligomers (TPCOs) are promising materials for organic light-emitting devices such as diodes, transistors and lasers. The synthetic flexibility of TPCOs enables facile tuning of their properties. In this study, we address the effect of various electron-donating and electron-withdrawing symmetric terminal substituents (fluorine, methyl, trifluoromethyl, methoxy, tert-butyl, and trimethylsilyl) on frontier orbitals, charge distribution, static polarizabilities, molecular vibrations, bandgaps and photoluminescence quantum yields of 5,5′-diphenyl-2,2′-bithiophene (PTTP). By combining DFT calculations with cyclic voltammetry and absorption, photoluminescence, and Raman spectroscopies, we show that symmetric terminal substitution tunes the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies of TPCOs within a range of ∼0.7 eV, shifts the frequencies of the vibrational modes associated with the phenyl rings, changes the photoluminescence quantum yield by about two-fold and slightly changes the bandgap by ∼0.1 eV. We demonstrate that these effects are governed by two factors: the Hammet constant of the substituents and their involvement in the π-conjugation/hyperconjugation described by the effective conjugation length of the substituted oligomer. A detailed picture underlying the effect of the terminal substituents on the electronic, vibrational and optical properties of TPCOs is presented. Overall, the unraveled relationships between the structure and the properties of the substituted PTTPs should facilitate a rational design of π-conjugated (co-)oligomers for efficient organic optoelectronic devices.
AB - Owing to the combination of efficient charge transport and bright luminescence, thiophene-phenylene co-oligomers (TPCOs) are promising materials for organic light-emitting devices such as diodes, transistors and lasers. The synthetic flexibility of TPCOs enables facile tuning of their properties. In this study, we address the effect of various electron-donating and electron-withdrawing symmetric terminal substituents (fluorine, methyl, trifluoromethyl, methoxy, tert-butyl, and trimethylsilyl) on frontier orbitals, charge distribution, static polarizabilities, molecular vibrations, bandgaps and photoluminescence quantum yields of 5,5′-diphenyl-2,2′-bithiophene (PTTP). By combining DFT calculations with cyclic voltammetry and absorption, photoluminescence, and Raman spectroscopies, we show that symmetric terminal substitution tunes the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies of TPCOs within a range of ∼0.7 eV, shifts the frequencies of the vibrational modes associated with the phenyl rings, changes the photoluminescence quantum yield by about two-fold and slightly changes the bandgap by ∼0.1 eV. We demonstrate that these effects are governed by two factors: the Hammet constant of the substituents and their involvement in the π-conjugation/hyperconjugation described by the effective conjugation length of the substituted oligomer. A detailed picture underlying the effect of the terminal substituents on the electronic, vibrational and optical properties of TPCOs is presented. Overall, the unraveled relationships between the structure and the properties of the substituted PTTPs should facilitate a rational design of π-conjugated (co-)oligomers for efficient organic optoelectronic devices.
KW - FIELD-EFFECT TRANSISTORS
KW - ORGANIC SINGLE-CRYSTALS
KW - CHARGE-TRANSPORT
KW - PHOTOLUMINESCENCE
KW - LUMINESCENCE
UR - http://www.scopus.com/inward/record.url?scp=85067128340&partnerID=8YFLogxK
U2 - 10.1039/c9cp00910h
DO - 10.1039/c9cp00910h
M3 - Article
C2 - 30968108
AN - SCOPUS:85067128340
VL - 21
SP - 11578
EP - 11588
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
SN - 1463-9076
IS - 22
ER -
ID: 20587717