RT Journal Article
T1 Tuning the helical sense and elongation of polymers through the combined action of the two components of tetraalkylammonium-anion salts
A1 Leiras Fernández, Seila
A1 Suárez Picado, Esteban
A1 Quiñoá Cabana, Emilio
A1 Riguera Vega, Ricardo
A1 Freire Iribarne, Félix Manuel
K1 Size effect
K1 Stretching degree
K1 Poly(phenylacetylene)s
K1 Chirality
K1 Helix
AB The helical sense and elongation of a helical polymer that bears the 4-ethynylanilide of (R)-α‑methoxy-α-phenylacetic acid [m-(R)-1] can be tuned by the action of the two components of tetraalkylammonium-anion salts. Thus, while the supramolecular PPA-anilide/anion interaction creates a chiroptical switch, inducing either P or M helical senses in the poly(phenylacetylene) (PPA) depending on the nature of the anion —P helix: fluoride (F−) or cyanide (CN−); M helix: acetate (OAc−), benzoate (OBz−) or azide (N3−)—, deprotonation of the anilide group by these anions in dry conditions makes it possible to play with the elongation of the PPA, depending on the size of the tetraalkylammonium group, which results in a colorimetric switch. Thus, a color change from yellow to deep red is obtained by deprotonation of the anilide group when a tetraabutylammonium salt is used, while yellow/light-red and yellow/orange color changes are obtained when the size of the tetraalkylammonium group is reduced. Structural and mechanistic studies confirm that the color change occurs when the counterion accommodates itself close to the pendant group once the anilide hydrogen is removed. This PPA/tetraalkylammonium association is responsible of elongation changes in the PPA and therefore on the conjugation of the polyene backbone that is accompanied with color changes. Moreover, this colorimetric switch also operates in the solid state and can be switched in a vacuum/air moisture cycle
PB Elsevier
SN 2666-5425
YR 2021
FD 2021
LK http://hdl.handle.net/10347/26731
UL http://hdl.handle.net/10347/26731
LA eng
NO Giant 2021, 7: 100068. https://doi.org/10.1016/j.giant.2021.100068
NO Financial support from MINECO (PID2019-109733GB-I00), Xunta de Galicia (ED431C 2018/30; Centro singular de investigación de Galicia accreditation 2016–2019, ED431G/09 and the European Regional Development Fund (ERDF) is gratefully acknowledged. We also thank Servicio de Nanotecnología y Análisis de Superficies (CACTI, UVIGO)
DS Minerva
RD 24 abr 2026