Planar and Helical Dinaphthophenazines

[EN] In this study, we report the synthesis of a series of planar and helical dinaphthophenazines by cyclocondensation reactions between the newly developed 9,10-bis((triisopropylsilyl)ethynyl)-anthracene-1,2-dione and different diamines. Their optoelectronic and electrochemical properties are studied by ultraviolet-visible (UV-vis) spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and density functional theory calculations.A.M.-A. acknowledges support of the Basque Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country, Diputacion Foral de Guipuzcoa, Gobierno Vasco (BERC programme) and Gobierno de Espana (Project CEX2020-001067-M financed by MCIN/AEI/10.13039/501100011033). Technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF) is acknowledged. This project received funding from the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (grant agreement no. 722951). This project received funding from the European Union's Horizon 2020 Research and Innovation Programme under grant agreement nos. 664878 and 899895. F.C. and A.M.-A acknowledge that this project received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement no. 839626. M.M.-F. acknowledges support from the Portuguese Foundation for Science and Technology (FCT), under the project IF/00894/2015, and the project CICECO-Aveiro Institute of Materials, FCT ref UID/CTM/50011/2019, UIDB/50011/2020, and UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate c-financed by FEDER under the PT2020 Partnership Agreement

Doubling the Length of the Longest Pyrene-Pyrazinoquinoxaline Molecular Nanoribbons

[EN] Molecular nanoribbons are a class of atomically-precise nanomaterials for a broad range of applications. An iterative approach that allows doubling the length of the longest pyrene-pyrazinoquinoxaline molecular nanoribbons is described. The largest nanoribbon obtained through this approach-with a 60 linearly-fused ring backbone (14.9 nm) and a 324-atoms core (C276N48)-shows an extremely high molar absorptivity (values up to 1 198 074 M-1 cm(-1)) that also endows it with a high molar fluorescence brightness (8700 M-1 cm(-1)).This work was carried out with support from the Basque Science Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country, Diputacion de Guipuzcoa, Gobierno Vasco (BERC programme) and Gobierno de Espana (Project CEX2020-001067-M financed by MCIN/AEI/10.13039/501100011033). Technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF) is acknowledged. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 722951). This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 899895. In addition, support through the project IF/00894/2015, the advanced computing project CPCA/A2/2524/2020 granting access to the Navigator cluster at LCA-UC and within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020 funded by national funds through the Portuguese Foundation for Science and Technology I.P./MCTES is gratefully acknowledged

Inducing Single-Handed Helicity in a Twisted Molecular Nanoribbon

[EN] Molecular conformation has an important role in chemistry and materials science. Molecular nanoribbons can adopt chiral twisted helical conformations. However, the synthesis of single-handed helically twisted molecular nanoribbons still represents a considerable challenge. Herein, we describe an asymmetric approach to induce single-handed helicity with an excellent degree of conformational discrimination. The chiral induction is the result of the chiral strain generated by fusing two oversized chiral rings and of the propagation of that strain along the nanoribbon's backbone.This work was carried out with support from the Basque Science Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country, Gobierno Vasco (BERC Programme) and Gobierno de Espana (Ministerio de Ciencia e Innovacion, Plan Estatal de Investigacion Cientifica y Tecnica y de Innovacion). Technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF) is acknowledged. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 722951). This project has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 899895. In addition, support through the project IF/00894/2015, the advanced computing project CPCA/A2/2524/2020 granting access to the Navigator cluster at LCA-UC and within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 and UIDP/50011/2020 funded by national funds through the Portuguese Foundation for Science and Technology I.P./MCTES is gratefully acknowledged

Modulating Strain in Twisted Pyrene-Fused Azaacenes

The design and synthesis of strained aromatics provide an additional insight into the relationship between structure and properties. In the last years, several approaches to twist pyrene-fused azaacenes have been developed that allow to introduce twists of different sizes. Herein, we describe the synthesis of a new set of twisted dibenzotetraazahexacenes constituted by fused pyrene and quinoxaline residues that have been distorted by introducing increasingly larger substituents on the quinoxaline residues. Their twisted structure has been demonstrated by single-crystal X-ray diffraction. Furthermore, absorption, fluorescence, electrochemical and theoretical studies shine light on the effects of the substituents and twists on the optoelectronic and redox properties.This work was carried out with support from the Basque Science Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country, Diputación de Guipúzcoa, Gobierno Vasco (PIBA_2022_1_0031 and BERC programme) and Gobierno de España (Projects PID2021-124484OB-I00 and CEX2020-001067-M financed by MCIN/AEI/10.13039/501100011033). Project (PCI2022-132921) funded by the Agencia Estatal de Investigación through the PCI 2022 and M-ERA.NET 2021 calls. This project has received funding from the European Research Council (ERC) under the European Union's Horizon2020 research and innovation programme (Grant Agreement No. 722951). This work was funded by the European Union under the Horizon Europe grant 101046231. Technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF) is acknowledged. In addition, support through the project IF/00894/2015, the advanced computing project 2021.09622.CPCA granting access to the Navigator cluster at LCA-UC, and within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) is gratefully acknowledged

A Thiadiazole-capped Nanoribbon with 18 Linearly-Fused Rings

Polycyclic aromatic hydrocarbons that extend over 2 nm in one dimension are seen as monodisperse graphene nanoribbons, which have attracted significant attention for a broad range of applications in organic electronics and photonics. Herein we report the synthesis of a stable bisthiadiazole-capped pyrene-containing nanoribbon with 18 linearly fused rings (NR-18-TD). Thanks to the presence of alternating tert-butyl and tri-iso-butylsilyl groups, NR-18-TD is highly soluble in organic solvents and therefore its structure and fundamental optoelectronic, redox and electrical properties could be unambiguously established. This work illustrates that NR-18-TD is a promising soluble NR-based n-type semiconductor for applications in organic electronics.The authors are grateful to the Basque Science Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country (Grupo de Investigación GIU17/054 and SGIker), Gobierno de España (Ministerio de Economía y Competitividad CTQ2016-77970-R and CTQ2015-71936-REDT), Gobierno Vasco (BERC program), CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT ref. UID/CTM/50011/2013), Diputación Foral de Guipúzcoa (OF215/2016(ES)) and the FP7 framework program of the European Union (Marie Curie Career Integration Grant No. 618247 (NIRVANA)). This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 664878. This project has also received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 722951

A Sterically Congested Nitrogenated Benzodipentaphene with a Double π-Expanded Helicene Structure

Herein, we describe a series of three sterically congested nitrogenated benzodipentaphenes, one of which shows a highly distorted aromatic backbone with an unprecedented double π-expanded helicene structure.A.M.-A. acknowledge support of the Basque Science Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country (Grupo de Investigación No. GIU17/054), Gobierno Vasco (No. PIBA 2019-09 and BERC program), and Gobierno de España (Ministerio de Economı́a y Competitividad No. CTQ2016-77970-R) and thank for technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF). F.C. and A.M.-A acknowledge that this project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme, under the Marie Skłodowska-Curie Grant Agreement No. 839626. A.M.-A. acknowledge that this project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme (Grant Agreement No. 722951). A.S. acknowledges the support of Japan Society for the Promotion of Science (JSPS) with the KAKENHI Grant-in-Aid for Scientific Research (A) (Grant No. JP16H02285). M.M.-F. acknowledges support from the Portuguese Foundation for Science and Technology (FCT), under the project IF/00894/2015, and the project CICECO-Aveiro Institute of Materials, FCT ref. UID/CTM/50011/2019, UIDB/50011/2020, and UIDP/50011/2020, financed by national funds through the FCT/MEC and, when appropriate, cofinanced by FEDER, under the PT2020 Partnership Agreement

Monodisperse N‐Doped Graphene Nanoribbons Reaching 7.7 Nanometers in Length

The properties of graphene nanoribbons are highly dependent on structural variables such as width, length, edge structure, and heteroatom doping. Therefore, atomic precision over all these variables is necessary for establishing their fundamental properties and exploring their potential applications. An iterative approach is presented that assembles a small and carefully designed molecular building block into monodisperse N-doped graphene nanoribbons with different lengths. To showcase this approach, the synthesis and characterisation of a series of nanoribbons constituted of 10, 20 and 30 conjugated linearly-fused rings (2.9, 5.3, and 7.7 nm in length, respectively) is presented.We are grateful to the Basque Science Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country (SGIker), the Deutsche Forschungsgemeinschaft (MA 5215/4-1), Gobierno de Espana (Ministerio de Economia y Competitividad CTQ2016-77970-R and CTQ2015-71936-REDT), Gobierno Vasco (BERC program and PC2015-1-01(0637)), Diputacion Foral de Guipuzcoa (OF215/2016(ES)), CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT ref. UID/CTM/50011/2013), ON2 (NORTE-07-0162-FEDER-000086), and the FP7 framework program of the European Union (ERA Chemistry, Marie Curie Career Integration Grant No. 618247 (NIRVANA)). This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 664878. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 722951)

Exclusive Substitutional Nitrogen Doping on Graphene Decoupled from an Insulating Substrate

The on-surface synthesis of atomically flat N-doped graphene on oxidized copper is presented. Besides circumventing the almost standard use of metallic substrates for growth, this method allows producing graphene with similar to 2.0 at % N in a substitutional configuration directly decoupled from the substrate. Angle-resolved photoemission shows a linear energy-momentum dispersion where the Dirac point lies at the Fermi level. Additionally, the N functional centers can be selectively tailored in sp(2) substitutional configuration by making use of a purpose-made molecular precursor: dicyanopyrazophenanthroline (C16H6N6).P.A. acknowledges the contribution of the CA COST Action no. CA15107 (MultiComp). M.C. and A.M.-A. acknowledge support of the Basque Science Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country (Grupo de Investigacion GIU17/054 and SGIker), Gobierno Vasco (BERC program), and Gobierno de Espana (Ministerio de Economia y Competitividad CTQ2016-77970R). M.C. and A.M.-A. thank technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF). A.M.-A. acknowledges that this project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation Programme (grant agreement no. 722951)

Wall- and Hybridisation-Selective Synthesis of Nitrogen-Doped Double-Walled Carbon Nanotubes

Controlled nitrogen-doping is a powerful methodology to modify the properties of carbon nanostructures and produce functional materials for electrocatalysis, energy conversion and storage, and sensing, among others. Herein, we report a wall- and hybridisation-selective synthetic methodology to produce double-walled carbon nanotubes with an inner tube doped exclusively with graphitic sp2-nitrogen atoms. Our measurements shed light on the fundamental properties of nitrogen-doped nanocarbons opening the door for developing their potential applications

Wall- and Hybridisation-Selective Synthesis of Nitrogen-Doped Double-Walled Carbon Nanotubes

open10siControlled nitrogen-doping is a powerful methodology to modify the properties of carbon nanostructures and produce functional materials for electrocatalysis, energy conversion and storage, and sensing, among others. Herein, we report a wall- and hybridisation-selective synthetic methodology to produce double-walled carbon nanotubes with an inner tube doped exclusively with graphitic sp2-nitrogen atoms. Our measurements shed light on the fundamental properties of nitrogen-doped nanocarbons opening the door for developing their potential applications.openCarini M.; Shi L.; Chamberlain T.W.; Liu M.; Valenti G.; Melle-Franco M.; Paolucci F.; Khlobystov A.N.; Pichler T.; Mateo-Alonso A.Carini M.; Shi L.; Chamberlain T.W.; Liu M.; Valenti G.; Melle-Franco M.; Paolucci F.; Khlobystov A.N.; Pichler T.; Mateo-Alonso A