doi:10.1021/acs.joc.0c02438engTejeda-Orusco, V.Andreu, R.Orduna, J.Villacampa, B.Franco, S.Civera, A.Twisted One-Dimensional Charge Transfer and Related Y-Shaped Chromophores with a 4 H-Pyranylidene Donor: Synthesis and Optical PropertiesART-2021-123284Three series of push-pull derivatives bearing 4H-pyranylidene as electron donor group and a variety of acceptors were designed. On one hand, one-dimensional chromophores with a thiophene ring (series 1H) or 5-dimethylaminothiophene moiety (series 1N) as an auxiliary donor, non-coplanar with the p-conjugated system, were synthesized. On the other hand, related two-dimensional (2D) Y-shaped chromophores (series 2) were also prepared to compare how the diverse architectures affect the electrochemical, linear, and second-order nonlinear optical (NLO) properties. The presence of the 5-dimethylaminothiophene moiety in the exocyclic C= C bond of the pyranylidene unit gives rise to oxidation potentials rarely low, and the protonation (with an excess of trifluoroacetic acid) of its derivatives results in the apparition of a new blue-shifted band in the UV-visible spectra. The analysis of the properties of derivatives with and without the additional thiophene ring shows that this auxiliary donor leads to a higher NLO response, accompanied by an enhanced transparency. Y-shaped chromophores of series 2 present a blue-shifted absorption, higher molar extinction coefficients, and higher Eox values compared to their linear twisted counterparts. As concerns NLO properties, 2D Y-shaped architecture gives rise to somewhat lower µß values (except for thiobarbiturate derivatives).2021http://zaguan.unizar.es/record/10958910.1021/acs.joc.0c02438http://zaguan.unizar.es/record/109589oai:zaguan.unizar.es:109589info:eu-repo/grantAgreement/ES/DGA-FEDER-FSE 2014–2020/E14-17Rinfo:eu-repo/grantAgreement/ES/MICINN/PID2019-104307GB-I00-AEI-10.13039-501100011033info:eu-repo/grantAgreement/ES/UZ/UZ2019-CIE-01Journal of Organic Chemistry 86 (2021), 3152-3163byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess