Borylated Subphthalocyanines: Versatile Precursors for the Preparation of Functional Bowl-Shaped Aromatics

The peripheral borylation of porphyrinoids has become a key step to prepare advanced functional materials. This study reports the synthesis, electronic properties, and reactivity of borylated subphthalocyanines. These compounds, which are prepared by Suzuki–Miyaura borylation in excellent yields, are easily purified, display a great stability, and serve as powerful starting materials for the post-functionalization of SubPcs via cross-coupling reactions. Remarkably, this novel approach is more efficient than the methodologies already described and enables the preparation of exotic systems, such as SubPc dimeric species linked by C−C bonds, which are not accessible so far and present promising properties for optoelectronic devicesWe gratefully acknowledge financial support from MICINN (PID2020-116490GB-I00 and TED2021-131255B-C43), the Comunidad de Madrid and the Spanish State through the Recovery, Transformation and Resilience Plan [“MATERIALES DISRUPTIVOS BIDIMENSIONALES (2D)” (MAD2D-CM)-MRR MATERIALES AVANZADOS], and the European Union through the Next Generation EU funds). IMDEA Nanociencia acknowledges support from the Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, Grant SEV2016-0686). J.L. acknowledges MECD, Spain, for a F.P.U. Fellowshi

Phthalocyanines and Porphyrinoid Analogues as Hole-and Electron-Transporting Materials for Perovskite Solar Cells

Organic–inorganic lead halide perovskite absorbers in combination with electron and hole transporting selective contacts result in power conversion efficiencies of over 23% under AM 1.5 sun conditions. The advantage of perovskite solar cells is their simple fabrication through solution-processing methods either in n-i-p or p-i-n configurations. Using TiO2 or SnO2 as an electron transporting layer, a compositionally engineered perovskite as an absorber layer, and Spiro-OMeTAD as a HTM, several groups have reported over 20% efficiency. Though perovskite solar cells reached comparable efficiency to that of crystalline silicon ones, their stability remains a bottleneck for commercialization partly due to the use of doped Spiro-OMeTAD. Several organic and inorganic hole transporting materials have been explored to increase the stability and power conversion efficiency of perovskite solar cells. IIn this review, we analyse the stability and efficiency of perovskite solar cells incorporating phthalocyanine and porphyrin macrocycles as hole- and electron transporting materials. The π–π stacking orientation of these macrocycles on the perovskite surface is important in facilitating a vertical charge transport, resulting in high power conversion efficiencyWe are grateful for the financial support of the MINECO, Spain (CTQ2017-85393-P) and the Comunidad de Madrid (FOTOCARBON, S2013/MIT-2841). IMDEA Nanociencia acknowledges support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, Grant SEV-2016-0686). MKN thanks the EPFL and the Swiss National Science Foundatio

Photoinduced energy transfer in ZnCdSeS quantum dot-phthalocyanines hybrids

In this article, interaction between ZnCdSeS quantum dot (QD) and phthalocyanines with variable linker has been reported. Steady-state and time-resolved spectroscopic investigation reveals that only photoinduced energy transfer occurs from QD to phthalocyanines. To evaluate quantitatively the energy transfer, the Poisson statistics of QD-dye complex formation was used in the analysis of steady-state and time-resolved emission quenching, which allows to estimate the energy transfer rate constant for an ideal one-to-one complex. The measured rate constants are compared to the rates evaluated based on the classic Förster theory, which shows roughly 1 nm discrepancy in the energy transfer distance estimation, or one order in magnitude discrepancy in the transfer rate constants.S.M. is grateful to the TUT postdoctoral programme. T.T. is grateful for the financial support of the MINECO, Spain (CTQ2017-85393-P), the Comunidad de Madrid (FOTOCARBON, S2013/MIT-2841). IMDEA Nanociencia acknowledges support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, Grant SEV-2016-0686)

Unveiling polymerization mechanism in pH-regulated supramolecular fibers in aqueous media

An amine functionalized C3-symmetric benzotrithiophene (BTT) monomer has been designed and synthetized in order to form pH responsive one-dimensional supramolecular polymers in aqueous media. While most of the reported studies looked at the effect of pH on the size of the aggregates, herein, a detailed mechanistic study is reported, carried out upon modifying the pH to trigger the formation of positively charged ammonium groups. A dramatic and reversible change in the polymerization mechanism and size of the supramolecular fibers is observed and ascribed to the combination of Coulombic repulsive forces and higher monomer solubility. Furthermore, the induced frustrated growth of the fibers is further employed to finely control the one-dimensional supramolecular polymerisation and copolymerization processes.Financial support from MINECO (CTQ2017-85393-P) and ERA-NET/European Commission/MINECO (EuroNanoMed2017-191/PCIN-2017-042) is acknowledged by T.T. IMDEA Nanociencia acknowledges support from the “Severo Ochoa” Programme for Centres of Excellence in R&D (MINECO, Grant SEV2016-0686). M.G.I thanks Santander Talent Atraction Research (STAR2) for finantial support. This work was also financially supported by Spanish Ministry of Science and Innovation (PID2019-109450RB-I00/AEI/10.13039/501100011033), European Research Council/Horizon2020 (ERC-StG-757397), la Caixa Foundation (ID 100010434) and by the Generalitat de Catalunya (2017 SGR 01536) to S.P. and L.A

Catalyst Development for High-Temperature Polymer Electrolyte Membrane Fuel Cell (HT-PEMFC) Applications

A constant increase in global emission standard is causing fuel cell (FC) technology to gain importance. Over the last two decades, a great deal of research has been focused on developing more active catalysts to boost the performance of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFC), as well as their durability. Due to material degradation at high-temperature conditions, catalyst design becomes challenging. Two main approaches are suggested: (i) alloying platinum (Pt) with low-cost transition metals to reduce Pt usage, and (ii) developing novel catalyst support that anchor metal particles more efficiently while inhibiting corrosion phenomena. In this comprehensive review, the most recent platinum group metal (PGM) and platinum group metal free (PGM-free) catalyst development is detailed, as well as the development of alternative carbon (C) supports for HT-PEMFCsThis work was financially supported by the Innovation Fund Denmark (MAKE-FC-LAST, 2079-00005B) and the Energy Technology Development and Demonstration (EUDP) Program (COBRA-Drive and 64018-0118). The authors gratefully acknowledge financial support from the Spanish MINECO through the Project PID2020- 116490GB-I00. The authors also thank financial support from the Comunidad de Madrid and the Spanish State through the Recovery, Transformation, and Resilience Plan [“Materiales Disruptivos Bidimensionales (2D)” (MAD2D-CM) (UAM1)-MRR Materiales Avanzados], and the European Union through the Next Generation EU funds. IMDEA Nanociencia acknowledges support from the “Severo Ochoa” Programme for Centres of Excellence in R&D (MINECO, grant SEV2016-0686

Soluble Ruthenium Phthalocyanines as Semiconductors for Organic Thin-Film Transistors

Ruthenium phthalocyanine (RuPcs) are multipurpose compounds characterized by their remarkable reactivity and photoelectronic properties, which yield a broad synthetic scope and easy derivatization at the axial position. However, RuPcs have been underexplored for use in organic thin-film transistors (OTFTs), and therefore new studies are necessary to provide basic insight and a first approach in this new application. Herein, two novel RuPc derivatives, containing axial pyridine substituents with aliphatic chains (RuPc(CO)(PyrSiC6) (1) and RuPc(PyrSiC6)2 (2), were synthesized, characterized, and tested as the organic semiconductor in OTFTs. RuPc thin-films were characterized by X-ray diffraction (XRD), and atomic force microscopy (AFM) to assess film morphology and microstructure. 1 displayed comparable p-type device performance to other phthalocyanine-based OTFTs of similar design, with an average field effect mobility of 2.08×10−3 cm2 V−1 s−1 in air and 1.36×10−3 cm2 V−1 s−1 in nitrogen, and threshold voltages from −11 V to −20 V. 2 was found to be non-functional as the semiconductor in the device architecture used, likely as a result of significant differences in thin-film formation. The results of this work illustrate a promising starting point for future development of RuPc electronic devices, particularly in this new family of OTFT

Tuning fluorescence and singlet oxygen quantum yields of subporphyrazines by axial functionalization

The axial functionalization of Subporphyrazines (SubPzs) with unreported alkoxy groups, carboxy and carboperoxy rests, as well as sulfanyl, aryl and amino groups, forming B−O, B−S, B−C, and B−N bonds, respectively, has been investigated. The studied oxygen nucleophiles include aromatic and sterically demanding aliphatic alcohols, along with carboxylic acids and peracids. In general, direct substitution of the chloro-SubPz by oxygen nucleophiles of diverse nature proceeds smoothly, with yields of the isolated alkoxy and carboxy-substituted SubPzs ranging from 49 to 100 %. Conversely, direct substitution with sulphur, carbon and nitrogen nucleophiles do not afford the corresponding substituted SubPzs. In these cases, a stepwise procedure involving an axial triflate-SubPz intermediate was employed, affording only the phenyl-SubPz in 8 % yield. The major compound under these conditions was the unreported SubPz μ-oxo dimer, presumably arising from substitution of the triflate-SubPz by the in situ generated hydroxy-SubPz. This result indicates a quite low reactivity of the TfO-SubPz intermediate with carbon, sulphur and nitrogen nucleophiles. All SubPzs prepared in this work exhibited fluorescence at 510–515 nm with quantum yields ranging from 0.1 to 0.24. Additionally, all SubPzs generated singlet oxygen, with ΦΔ values ranging from 0.15 to 0.57, which show no apparent correlation with the axial substituentsPID2020-116490GB-I00, TED2021-131255B-

Modulating the electron transporting properties of Subphthalocyanines for inverted perovskite solar cells

The lack of organic non-fullerene ETMs with good electron transport and device stability is an important problem for the further development and commercialization of perovskite solar cells. Herein, the use of SubPcs as ETMs in PSCs is explored. To this end, we analyze the influence of SubPc peripheral functionalization on the efficiency and stability of p-i-n PSCs. Specifically, ETMs based on three SubPcs (with either six or twelve peripheral fluorine and chlorine atoms) have been incorporated into PSCs with the perovskite layer deposited by solution processing (CsFAMAPbIBr). The device performance and morphology of these devices are deeply analyzed using several techniques, and the interfacial effects induced by the SubPcs are studied using photoluminescence and TR-PL. It is observed that the device stability is significantly improved upon insertion the SubPc layer. Moreover, the impact of the SubPc layer-thickness is assessed. Thus, a maximum power conversion efficiency of 13.6% was achieved with the champion devic

Anthracene-Fused Oligo-BODIPYs: a new class of π-extended NIR-absorbing materials

Large π-conjugated systems are key in the area of molecular materials. Herein, we prepare via AuI - catalyzed cyclization a series of fully π-conjugated anthracene-fused oligo-BODIPYs. Their structural and optoelectronic properties were studied by several techniques, ranging from X-ray, UV/Vis, and cyclic voltammetry to transient absorption spectroscopy. As a complement, their electronic structures were explored by means of Density Functional Theory (DFT) calculations. Depending on the size and shape of the π-conjugated skeleton, unique features—such as face-to-face supramolecular organization, NIR absorption and fluorescence as well as strong electron accepting character—were noted. All in all, the aforementioned features render them valuable for technological applicationsments We gratefully acknowledge financial support from the Spanish MICINN through Projects PID2020-116490GB-I00 (Porphyrinoids) and TED2021-131255B-C43 (PERSOLAR). We also thank financial support to the Comunidad de Madrid (MAD2D-CM) and MICINN through project “Materiales disruptivos bidimensionales (2D)” within the Plan de recuperación, transformación y resiliencia (Materiales avanzados). IMDEA Nanociencia acknowledges support from the “Severo Ochoa” Programme for Centres of Excellence in R&D (MINECO, Grant SEV2016-0686). J.L. acknowledges MECD, Spain, for a F.P.U. fellowship. European Commission under the Marie Sklodowska-Curie Action Cofund 2015 (EU project 713366-InterTalentum) is acknowledged for the support for G.D.S. Generous allocation of computational time from the Centro de Computación Científica UAM is gratefully acknowledged. Work in Erlangen was supported by the Deutsche Forschungsgemeinschaft (DFG) through SFB 953 project B10 and the Bavarian Collaborative Research Project “Solar Technologies go Hybrid” (SolTech