TY - JOUR
T1 - Raman spectroscopic characterization of polyselenophenes and poly(3,4-ethylenenedioxyselenophene)s
AU - Ferrõn, Cristina Capel
AU - Sheynin, Yana
AU - Li, Mao
AU - Patra, Asit
AU - Bendikov, Michael
AU - Lõpez Navarrete, Juan T.
AU - Hernández, Victor
AU - Ruiz Delgado, M. Carmen
PY - 2014/6
Y1 - 2014/6
N2 - Herein we present novel Raman spectroscopic studies carried out for polyselenophene (PSe), poly(3,4-ethylenedioxyselenophene) (PEDOS), and alkyl-substituted poly(alkyl-3,4-ethylenedioxyselenophene) (PEDOS-Cn: n=2, 8, and 12) homologues. These spectroscopic data are combined with morphological and structural analysis techniques, such as AFM, and DFT simulations. An investigation into the extent of π-conjugation in PSe is presented by comparing its spectral signatures with those of a homologous series of oligoselenophenes. Our experimental data suggest that π-conjugation in the PSe backbone extends to more than six selenophene units. The incorporation of ethylenedioxy (EDO) groups in PEDOS results in a more complex spectrum and a downshift of the C-C/C-C stretching vibration (or effective conjugation coordinate (ECC) mode); this provides evidence for an improvement in the π-conjugational properties along the PSe backbone upon EDO substitution. The dispersity of π-conjugation lengths in different PEDOS samples obtained through different synthetic routes is evaluated as a function of different structural factors. Finally, we present experimental evidence that the insertion of alkyl chains into the EDO units slightly impacts on the π-conjugational properties of the PEDOS backbone in the non-annealed samples (with an improved π-electron delocalization found in PEDOS-C8), but moderately affects the degree of molecular order of polymer films upon thermal annealing.
AB - Herein we present novel Raman spectroscopic studies carried out for polyselenophene (PSe), poly(3,4-ethylenedioxyselenophene) (PEDOS), and alkyl-substituted poly(alkyl-3,4-ethylenedioxyselenophene) (PEDOS-Cn: n=2, 8, and 12) homologues. These spectroscopic data are combined with morphological and structural analysis techniques, such as AFM, and DFT simulations. An investigation into the extent of π-conjugation in PSe is presented by comparing its spectral signatures with those of a homologous series of oligoselenophenes. Our experimental data suggest that π-conjugation in the PSe backbone extends to more than six selenophene units. The incorporation of ethylenedioxy (EDO) groups in PEDOS results in a more complex spectrum and a downshift of the C-C/C-C stretching vibration (or effective conjugation coordinate (ECC) mode); this provides evidence for an improvement in the π-conjugational properties along the PSe backbone upon EDO substitution. The dispersity of π-conjugation lengths in different PEDOS samples obtained through different synthetic routes is evaluated as a function of different structural factors. Finally, we present experimental evidence that the insertion of alkyl chains into the EDO units slightly impacts on the π-conjugational properties of the PEDOS backbone in the non-annealed samples (with an improved π-electron delocalization found in PEDOS-C8), but moderately affects the degree of molecular order of polymer films upon thermal annealing.
KW - Raman spectroscopy
KW - conjugation
KW - heterocycles
KW - polymers
KW - thermochemistry
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U2 - 10.1002/ijch.201400024
DO - 10.1002/ijch.201400024
M3 - Article
AN - SCOPUS:84903317633
VL - 54
SP - 759
EP - 766
JO - Israel Journal of Chemistry
JF - Israel Journal of Chemistry
SN - 0021-2148
IS - 5-6
ER -