31 research outputs found
Aggregation-Induced Emission and Circularly Polarized Luminescence Duality in Tetracationic Binaphthyl-Based Cyclophanes
Here, we report an approach to the synthesis of highly charged enantiopure cyclophanes by the insertion of
axially chiral enantiomeric binaphthyl fluorophores into the constitutions of pyridinium-based macrocycles. Remarkably,
these fluorescent tetracationic cyclophanes exhibit a significant AIE compared to their neutral optically active binaphthyl
precursors. A combination of theoretical calculations and time-resolved spectroscopy reveal that the AIE originates
from limited torsional vibrations associated with the axes of chirality present in the chiral enantiomeric binaphthyl units
and the fine-tuning of their electronic landscape when incorporated within the cyclophane structure. Furthermore, these
highly charged enantiopure cyclophanes display CPL responses both in solution and in the aggregated state. This unique
duality of AIE and CPL in these tetracationic cyclophanes is destined to be of major importance in future development
of photonic devices and bio-applications.National Science Foundation (NSF) DMR-2003739United States Department of Energy (DOE) DE-SC0000989SHyNE Resource NSF ECCS-2025633IINNorthwestern's MRSEC program NSF DMR-1720139MCIN/AIE EQC2019-006543-PERDF A way of making EuropeFEDER(ERDF)/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades P18-FR-287
On-Surface Thermal Stability of a Graphenic Structure Incorporating a Tropone Moiety
We acknowledge the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (ERC-2015-STG-677023 and ERC-2013-SYG-610256 NANOCOSMOS) and the innovation program under grant agreement No. 696656 (GrapheneCore1-Graphene-based disruptive technologies) and grant agreement No. 785219 (GrapheneCore2-Graphene-based disruptive technologies) for financial support. Grants PGC2018-101181-B-I00 and MAT2017-85089-C2-1-R funded by MCIN/AEI/ 10.13039/501100011033 and “ERDF A way of making Europe” by the “European Union”, and grant PID2020-113142RB-C21 funded by MCIN/AEI/ 10.13039/501100 011033 also provided financial support. We also acknowledge Comunidad de Madrid via Programa de Investigación Tecnologías 2018 (FOTOART-CM S2018/NMT-4367), the Swiss National Science Foundation (grant number 200020-182015), the NCCR MARVEL funded by the Swiss National Science Foundation (grant number 51NF40-182892) and FEDER/Junta de Andalucía-Consejería de Economía y Conocimiento (B-FQM-428-UGR20). C. S. S. and N. R. A. acknowledge Grants RYC2018-024364-I and BES-2015-072642, respectively, funded by MCIN/AEI/ 10.13039/501100011033 and “ESF Investing in your future”. I. R. M. acknowledges the University of Granada for her postdoctoral contract (Contrato Puente-Plan Propio UGR). F.V. thanks Ministerio de Universidades for the FPU grant (FPU18/05938).On-surface synthesis, complementary to wet chemistry, has been demonstrated to be a
valid approach for the synthesis of tailored graphenic nanostructures with atomic precision. Among
the different existing strategies used to tune the optoelectronic and magnetic properties of these
nanostructures, the introduction of non-hexagonal rings inducing out-of-plane distortions is a promising pathway that has been scarcely explored on surfaces. Here, we demonstrate that non-hexagonal
rings, in the form of tropone (cycloheptatrienone) moieties, are thermally transformed into phenyl or
cyclopentadienone moieties upon an unprecedented surface-mediated retro–Buchner-type reaction
involving a decarbonylation or an intramolecular rearrangement of the CO unit, respectively.Junta de Andalucía-Consejería de Economía y Conocimiento
B-FQM-428-UGR20, BES-2015-072642, RYC2018-024364-IMCINMinisterio de Universidades
FPU18/05938European Commission
FOTOART-CM S2018/NMT-4367European Research CouncilSchweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung 200020-182015European Social FundUniversidad de GranadaEuropean Regional Development Fund
011033, PID2020-113142RB-C21, S2018/NMT-4367National Center of Competence in Research Materials’ Revolution: Computational Design and Discovery of Novel Materials
51NF40-182892Agencia Estatal de Investigació
Cp2TiCl-catalyzed highly stereoselective intramolecular epoxide allylation using allyl carbonates
A useful method for the diastereoselective synthesis of vinyl substituted carbo- and heterocycles is described. Highly functionalized structures difficult to achieve by other methodologies are obtained in a single step by this procedure.This research was funded by the Ministerio de Ciencia e Innovación (Spain) (project CTQ-2011.22455). I.R.M. thanks the MEC (Spain) for a predoctoral FPU fellowship. A.M. thanks the University of Granada for a postdoctoral contract (‘Contrato Puente’). A.G.C. thanks the MICINN (Spain) for a postdoctoral contract ‘Juan de la Cierva’ and University of Granada
Dibenzocycloheptatriene as end-group of Thiele and tetrabenzo-Chichibabin hydrocarbons
The authors are grateful for the financial support from: MICIU/FEDER/AEI, Spain (PG2018-101181-B-I00, PGC2018-095808B-I00, MAT2016-80826-R, FIP-2018-HECTIC-PTM, Prometeo2019/076 and the "Severo Ochoa" Programme for Centres of Excellence in R & D; SEV-2015-0496), the European Research Council (ERC) (677023), DGR (Catalunya) (2017-SGR-918), and SNSF (Switzerland, TS., PZ00P2_174175). We thank the CSIRC-Alhambra and SciCore (Basel, Switzerland) for supercomputing facilities and the Servei de RMN, UAB, for instrument time.Thiele (Th) and tetrabenzo-Chichibabin (TBC) derivatives with terminal dibenzocycloheptatriene (DBHept) units were prepared. A clear correlation between their electronic and molecular structures was stablished. Insights into their closed- or open-shell ground states were gained, where particular contribution of the heptagonal carbocycles as end-groups was proved. Remarkably, a thermally accessible triplet diradical configuration was confirmed for theDBHept-TBCcompound.MICIU/FEDER/AEI, Spain
PG2018-101181-B-I00
PGC2018-095808B-I00
MAT2016-80826-R
FIP-2018-HECTIC-PTM
Prometeo2019/076MICIU/FEDER/AEI, Spain ("Severo Ochoa" Programme for Centres of Excellence in RD)
SEV-2015-0496European Research Council (ERC)
677023DGR (Catalunya)
2017-SGR-918Swiss National Science Foundation (SNSF)
PZ00P2_17417
Vinyl sulfonyl chemistry-driven unidirectional transport of a macrocycle through a [2]rotaxane
This work has been financially supported by FEDER(EDRF)/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (P18-FR-2877), grant PID2020-112906GA-I00 funded by MCIN/AIE (/10.13039/501100011033) and Ministerio de Economia y Competitividad (MINECO, Spain) (CTQ2014-55474-C2-2-R and CTQ2017-86125P, co-financed by FEDER funds). Funding for open access APCs provided by Universidad de Granada through a Paid by Read & Publish agreement with RSC.By applying a combination of the coupling-and-decoupling (CAD) chemistry of the vinyl sulfonate group with the click thia-Michael addition to the vinyl sulfone group (MAVS) we performed the irreversible unidirectional transportation of the ring through the linear component in a [2]rotaxane by a chemically and pH-driven flashing energy ratchet mechanism. The design is based on a monostoppered thread precursor bearing a sulfonate stopper, a vinyl sulfone group on the unstoppered end and a dibenzylammonium unit as recognition site for the dibenzo-24-crown-8 macrocycle. First, the ring enters from the vinyl sulfone side and the rotaxane is capped through a thia-Michael addition reaction. Then, the cleavage of the sulfonate group of the opposite stopper using MgBr2 as chemical stimulus and subsequent addition of base (Et3N) promoted the controlled and directional release of the macrocycle into the bulk under mild conditions. The efficiency of the system allowed the in situ operation as demonstrated by NMR and HRMS techniques.FEDER(EDRF)/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades - MCIN/AIE P18-FR-2877Ministerio de Economia y Competitividad (MINECO, Spain) (FEDER funds) CTQ2014-55474-C2-2-R;
CTQ2017-86125PUniversidad de GranadaRSCMCIN/AIE PID2020-112906GA-I0
Combining Defects in a Single Nanographene: A Fully Helical Saddle Ribbon
The controlled preparation of well-defined distorted nanographenes by a bottom-up approach based on organic synthesis permits the direct establishment of unprecedented structure–property relationships in carbon nanostructures. The simultaneous incorporation
of various defects in nanographenes affords highly curved structures
with novel or enhanced photophysical properties. In this sense, we recently reported a fully helical and saddle-shaped nanographene ribbon
containing the first undecabenzo[7]helicene unit. Both its linear and
nonlinear optical properties are enhanced in comparison with those of
other partially π-extended [7]helicenes. Moreover, the new superhelicene exhibits the highest emission dissymmetry factor (glum) reported
to date for a homochiral nanographene. The combination of both nonlinear and chiroptical properties in nanographenes opens up new possible future applications for those distorted nanostructures.This work was supported by the European Research Council (ERC) under the European Union´s Horizon 2020 research and innovation program (ERC-2015-STG-677023) and the Ministerio de Economía y
Competitividad (Spain) (CTQ2015-70283-P, BES-2016-076371, IJCI2016-27793 and RyC-2013-12943). E.M. thanks the Fundação para a
Ciência e a Tecnologia for financial support (UID/NAN/50024/2013
and IF/00759/2013) (
Undecabenzo[7]superhelicene: a helical nanographene ribbon as CPL emitter
We report the synthesis and characterization of an
enantiopure superhelicene nanographene constituted by two saddleshaped
and one planar hexabenzocoronene (HBC) units arranged in
a helicoidal shape. This is, to the best of our knowledge, the first
undecabenzo[7]carbohelicene, i.e., the first fully π-extended
[7]helicene. Racemic resolution allowed its chiroptical properties
analysis revealing dissymmetry factors in the range of 2×10-3 both in
the absorption and in the emission measurements. Remarkably, nonlinear
photophysical analysis showed two-photon absorption crosssection
of 870 GM at 800 nm and a perfect overlapping between linear,
non-linear and chiral emission.-European Research Council (ERC-2015-STG-677023)
-Ministerio de Economía y Competitividad (MINECO, Spain): CTQ2015-70283-P
-Fundacao para a Ciencia e a tecnologia, Portugal: UID/NAN/50024/2013, IF/00759/2013
-Universidad de Granad
Circularly Polarized Luminescence of [6]Helicenes through Excited- State Intramolecular Proton Transfer
This project received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreements No. 716139 and No. 677023), the Swiss National Science Foundation (SNSF, PP00P2_170534, PP00P2_198900), Project PGC2018-101181-B-I00 funded by MCIN/AEI/ 10.13039/501100011033 FEDER "Una manera de hacer Europa", grant A-FQM-230-UGR20 funded by FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades and the German Academic Exchange Service (DAAD, postdoc fellowship to D. G.). Open access funding provided by the University of Zurich.We present the concept of combining circularly polarized luminescence (CPL) and excited-state intramolecular proton transfer (ESIPT) features into a single molecule as a strategy to generate high-performance ESIPT-based CPL materials. For this purpose, a [6]helicene bearing two ESIPT structural units was synthesized using a double Suzuki-Miyaura reaction and a double C(sp(2))-H hydroxylation approach. The photophysical properties of the doubly hydroxylated [6]helicene were studied in parallel with a non-hydroxylated [6]helicene control compound, revealing that the presence of a chiral [6]helicene unit results in a strong CPL response and the presence of the ESIPT units in a considerable red shift. The red-shifted emission along with the outstanding g(lum) (approximate to 10(-2)) and a large Stokes shift makes the doubly hydroxylated [6]helicene a promising candidate for use in optoelectronics.European Research Council (ERC) 716139
677023Swiss National Science Foundation (SNSF) PP00P2_170534
PP00P2_198900Deutscher Akademischer Austausch Dienst (DAAD)University of ZurichMCIN/AEI FEDER "Una manera de hacer Europa" PGC2018-101181-B-I00FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades A-FQM-230-UGR2
A triskelion-shaped saddle-helix hybrid nanographene
A unique rippled nanographene constituted by 52 fused
rings is presented in which six out-of-plane motifs are fully fused into
a triangular aromatic surface of ca. 2.5 nm size. Three units of an
unprecedented fully lateral π-extended octabenzo[5]helicene
together with three units of saddle-shaped heptagonal rings are
combined in a single structure leading to a well-soluble warped
nanographene. The two pairs of possible enantiomers have been
isolated and their linear, non-linear and chiroptical properties
evaluated, revealing an outstanding quantum yield and brightness
values at low energy together with good chiroptical responses both
in the absorption and emissionWe acknowledge the European Research Council (ERC) under
the European Union’s Horizon 2020 research and innovation
program (ERC-2015-STG-677023) and the Ministerio de
Economía y Competitividad (MINECO, Spain) (CTQ2015-70283-
P, UNGR15-CE-3478, BES-2016-076371 and RyC-2013-12943).
E.M. thanks the Fundação para a Ciência e a tecnologia
(PTDC/NAN-MAT729317/2017 and PTDC/QUI-QFI/29319/2017).
We thank the CSIRC-Alhambra from the University of Granada
Chiral Distorted Hexa-peri-hexabenzocoronenes Bearing a Nonagon-Embedded Carbohelicene
We acknowledge the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (ERC-2015-STG-677023), the Ministerio de Ciencia, Innovacion y Universidades (MICIU/FEDER/AEI, Spain, PGC2018-101181-B-I00), the Universidad de Granada (UGR) (Plan Propio - Intensificacion de la Investigacion PP2017-PRI.I-02) and the Swiss National Science Foundation (Spark 2019 Grant CRSK-2_190365) for financial support. We thank the CSIRC-Alhambra, the Service and Support for Science IT (S3IT) of the University of Zurich and Prof.Dr. Michal Juriek for supercomputing facilities. Funding for open access charge: Universidad de Granada/CBUA.A new family of chiral saddle-helix hybrid nanographenes is reported. The first hexa-peri-hexabenzocoronene (HBC) analogues bearing a nine-membered carbocycle are presented. Furthermore, for the first time, pi-extended carbo[n]helicenes containing a nine-membered ring as part of the helical moiety have been synthesized. The combination of a [5]helicene moiety and a nonagon ring in a single chiral motif induces a tremendous distortion from planarity into the nanographenic structures compared to other saddle-helix hybrids such as heptagon- and octagon-containing pi-extended carbo[5]helicenes. In fact, the interplanar angle of the two terminal rings reaches the largest angle (134.8 degrees) of a carbohelicene reported to date, thus being by far the most twisted helicene yet prepared. Photophysical properties evaluation showed improved absorption dissymmetry factors (|g(abs)|=4.2x10(-3)) in the new family of nonagon-containing pi-extended carbo[5]helicenes.European Research Council (ERC) ERC-2015-STG-677023Ministerio de Ciencia, Innovacion y Universidades (MICIU/FEDER/AEI, Spain) PGC2018-101181-B-I00Universidad de Granada (UGR) (Plan Propio - Intensificacion de la Investigacion) PP2017-PRI.I-02Swiss National Science Foundation (SNSF)
European Commission CRSK-2_190365Universidad de Granada/CBU