Research

12 pages, 3134 KiB

Open AccessArticle

Naphtalimide-Based Bipolar Derivatives Enabling High-Efficiency OLEDs

by Raminta Beresneviciute, Prakalp Gautam, Mangey Ram Nagar, Gintare Krucaite, Daiva Tavgeniene, Jwo-Huei Jou and Saulius Grigalevicius

Molecules 2023, 28(16), 6027; https://doi.org/10.3390/molecules28166027 - 12 Aug 2023

Viewed by 814

Abstract

Organic light-emitting diodes (OLEDs) have revolutionized the world of technology, making significant contributions to enhancing our everyday lives. With their exceptional display and lighting capabilities, OLEDs have become indispensable in various industries such as smartphones, tablets, televisions, and automotives. They have emerged as [...] Read more.

Organic light-emitting diodes (OLEDs) have revolutionized the world of technology, making significant contributions to enhancing our everyday lives. With their exceptional display and lighting capabilities, OLEDs have become indispensable in various industries such as smartphones, tablets, televisions, and automotives. They have emerged as a dominant technology, inspiring continuous advancements, and improvements. Taking inspiration from the remarkable advancements in OLED advancements, we have successfully developed naphtalimide-based compounds, namely RB-08, RB-09, RB-10, and RB-11. These compounds exhibit desirable characteristics such as a wide bandgap, high decomposition temperatures (306–366 °C), and very high glass transition temperatures (133–179 °C). Leveraging these exceptional properties, we have harnessed these compounds as green emitters in the aforementioned devices. Among the various fabricated OLEDs, the one incorporating the RB-11 emitter has exhibited superior performance. This specific configuration achieved maximum power efficacy of 7.7 lm/W, current efficacy of 7.9 cd/A, and external quantum efficiency of 3.3%. These results highlight the outstanding capabilities of our synthesized emitter and its potential for further advancements in the field. Full article

(This article belongs to the Special Issue Advanced Organic Molecular Electroactive Materials)

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8 pages, 1801 KiB

Open AccessCommunication

Electrochemical and Spectroscopic (FTIR) Evidence of Conducting Polymer-Cu Ions Interaction

by Gerardo Salinas and Bernardo A. Frontana-Uribe

Molecules 2023, 28(2), 569; https://doi.org/10.3390/molecules28020569 - 06 Jan 2023

Viewed by 1313

Abstract

In this work, we provide electrochemical and spectroscopic evidence of the conducting polymer-heavy metal ion interaction by comparing the electrochemical and spectroscopic behavior (FTIR) of two different conducting polymer-modified electrodes based on 3,4-alkoxythiophenes: 3,4-ethylenedioxythiophene (EDOT) and ortho-xylen-3,4-dioxythiophene (XDOT) during the potentiodynamic stripping [...] Read more.

In this work, we provide electrochemical and spectroscopic evidence of the conducting polymer-heavy metal ion interaction by comparing the electrochemical and spectroscopic behavior (FTIR) of two different conducting polymer-modified electrodes based on 3,4-alkoxythiophenes: 3,4-ethylenedioxythiophene (EDOT) and ortho-xylen-3,4-dioxythiophene (XDOT) during the potentiodynamic stripping of copper. By analyzing the electrochemical and spectroscopic results, it is possible to propose two different copper dissolution processes during the electrochemical stripping process, which depend on the conducting polymer used. With PEDOT matrix, stripping occurs in a two-step pathway, observed as two anodic peaks, involving the formation of the Cu⁺-PEDOT complex and the subsequent oxidation step of the Cu⁺ complex to release Cu²⁺ ions. On the other side, the experiments carried out let us propose the formation of a poorly stable Cu²⁺-PXDOT complex or a superficial mechanism for the Cu²⁺ release, characterized by a single stripping signal for this process. Thus, the incorporation of Cu ions into the matrix and the stripping release are intimately related to the chemical structure of the polymer used. Full article

(This article belongs to the Special Issue Advanced Organic Molecular Electroactive Materials)

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17 pages, 11065 KiB

Open AccessArticle

Design, Synthesis, Electronic Properties, and X-ray Structural Characterization of Various Modified Electron-Rich Calixarene Derivatives and Their Conversion to Stable Cation Radical Salts

by Rajendra Rathore, Sergey V. Lindeman and Sameh H. Abdelwahed

Molecules 2022, 27(18), 5994; https://doi.org/10.3390/molecules27185994 - 14 Sep 2022

Cited by 2 | Viewed by 1567

Abstract

We have designed and synthesized electron-rich calixarene derivatives, which undergo reversible electrochemical oxidation in a well-accessible potential range that allows the ready preparation and isolation of the corresponding cation radicals. Preparation of mono- or tetra-radical cation can be achieved by using stable aromatic [...] Read more.

We have designed and synthesized electron-rich calixarene derivatives, which undergo reversible electrochemical oxidation in a well-accessible potential range that allows the ready preparation and isolation of the corresponding cation radicals. Preparation of mono- or tetra-radical cation can be achieved by using stable aromatic cation-radical salts such as MA^+•, MB^+•, and NAP^+• as selective organic oxidants. The cation radicals of calixarenes are stable indefinitely at ambient temperatures and can be readily characterized by UV-vis-NIR spectroscopy. These cation radicals bind a single molecule of nitric oxide within its cavity with remarkable efficiency. Full article

(This article belongs to the Special Issue Advanced Organic Molecular Electroactive Materials)

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10 pages, 2011 KiB

Open AccessArticle

Effect of Side Chain Substituent Volume on Thermoelectric Properties of IDT-Based Conjugated Polymers

by De-Xun Xie, Tong-Chao Liu, Jing Xiao, Jing-Kun Fang, Cheng-Jun Pan and Guang Shao

Molecules 2021, 26(4), 963; https://doi.org/10.3390/molecules26040963 - 11 Feb 2021

Cited by 10 | Viewed by 2143

Abstract

A p-type thermoelectric conjugated polymer based on indacenodithiophene and benzothiadiazole is designed and synthesized by replacing normal aliphatic side chains (P1) with conjugated aromatic benzene substituents (P2). The introduced bulky substituent on P2 is detrimental to form the intensified [...] Read more.

A p-type thermoelectric conjugated polymer based on indacenodithiophene and benzothiadiazole is designed and synthesized by replacing normal aliphatic side chains (P1) with conjugated aromatic benzene substituents (P2). The introduced bulky substituent on P2 is detrimental to form the intensified packing of polymers, therefore, it hinders the efficient transporting of the charge carriers, eventually resulting in a lower conductivity compared to that of the polymers bearing aliphatic side chains (P1). These results reveal that the modification of side chains on conjugated polymers is crucial to rationally designed thermoelectric polymers with high performance. Full article

(This article belongs to the Special Issue Advanced Organic Molecular Electroactive Materials)

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15 pages, 3964 KiB

Open AccessFeature PaperArticle

Characterization of Inherently Chiral Electrosynthesized Oligomeric Films by Voltammetry and Scanning Electrochemical Microscopy (SECM)

by Margherita Donnici, Rosanna Toniolo, Serena Arnaboldi, Patrizia R. Mussini, Tiziana Benincori, Roberto Cirilli and Salvatore Daniele

Molecules 2020, 25(22), 5368; https://doi.org/10.3390/molecules25225368 - 17 Nov 2020

Cited by 2 | Viewed by 2061

Abstract

A voltammetric and scanning electrochemical microscopy (SECM) investigation was performed on an inherently chiral oligomer-coated gold electrode to establish its general properties (i.e., conductivity and topography), as well as its ability to discriminate chiral electroactive probe molecules. The electroactive monomer (S)-2,2′-bis(2,2′-bithiophene-5-yl)-3,3′-bibenzothiophene [...] Read more.

A voltammetric and scanning electrochemical microscopy (SECM) investigation was performed on an inherently chiral oligomer-coated gold electrode to establish its general properties (i.e., conductivity and topography), as well as its ability to discriminate chiral electroactive probe molecules. The electroactive monomer (S)-2,2′-bis(2,2′-bithiophene-5-yl)-3,3′-bibenzothiophene ((S)-BT₂T₄) was employed as reagent to electrodeposit, by cyclic voltammetry, the inherently chiral oligomer film of (S)-BT₂T₄ (oligo-(S)-BT₂T₄) onto the Au electrode surface (resulting in oligo-(S)-BT₂T₄-Au). SECM measurements, performed in either feedback or competition mode, using the redox mediators [Fe(CN)₆]⁴⁻ and [Fe(CN)₆]³⁻ in aqueous solutions, and ferrocene (Fc), (S)-FcEA, (R)-FcEA and rac-FcEA (FcEA is N,N-dimethyl-1-ferrocenylethylamine) in CH₃CN solutions, indicated that the oligomer film, as produced, was uncharged. The use of [Fe(CN)₆]³⁻ allowed establishing that the oligomer film behaved as a porous insulating membrane, presenting a rather rough surface. This was inferred from both the approach curves and linear and bidimensional SECM scans, which displayed negative feedback effects. The oligomer film acquired semiconducting or fully conducting properties when the Au electrode was biased at potential more positive than 0.6 V vs. Ag|AgCl|KCl. Under the latter conditions, the approach curves displayed positive feedback effects. SECM measurements, performed in competition mode, allowed verifying the discriminating ability of the oligo-(S)-BT₂T₄ film towards the (S)-FcEA and (R)-FcEA redox mediators, which confirmed the results obtained by cyclic voltammetry. SECM linear scans indicated that the enantiomeric discriminating ability of the oligo-(S)-BT₂T₄ was even across its entire surface. Full article

(This article belongs to the Special Issue Advanced Organic Molecular Electroactive Materials)

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26 pages, 4480 KiB

Open AccessFeature PaperArticle

Synthesis, Characterization, and Electrochemistry of Diferrocenyl β-Diketones, -Diketonates, and Pyrazoles

by Steve W. Lehrich, Julia Mahrholdt, Marcus Korb, Alexander Hildebrandt, Jannie C. Swarts and Heinrich Lang

Molecules 2020, 25(19), 4476; https://doi.org/10.3390/molecules25194476 - 29 Sep 2020

Cited by 5 | Viewed by 2445

Abstract

The synthesis of FcC(O)CH(R)C(O)Fc (Fc = Fe(η⁵-C₅H₄)(η⁵-C₅H₅); R = H, 5; ⁿBu, 7; CH₂CH₂(OCH₂CH₂)₂OMe, 9), [M(κ² [...] Read more.

The synthesis of FcC(O)CH(R)C(O)Fc (Fc = Fe(η⁵-C₅H₄)(η⁵-C₅H₅); R = H, 5; ⁿBu, 7; CH₂CH₂(OCH₂CH₂)₂OMe, 9), [M(κ²O,O′-FcC(O)CHC(O)Fc)_n] (M = Ti, n = 3, 10; M = Fe, n = 3, 11; M = BF₂, n = 1, 12), and 1-R′-3,5-Fc₂-^cC₃HN₂ (R′ = H, 13; Me, 14; Ph, 15) is discussed. The solid-state structures of 5, 7, 9, 12, 13, 15, and 16 ([TiCl₂(κ²O,O′-PhC(O)CHC(O)Ph)₂]) show that 7 and 9 exist in their β-diketo form. Compound 13 crystallizes as a tetramer based on a hydrogen bond pattern, including one central water molecule. The electrochemical behavior of 5–7 and 9–16 was studied by cyclic and square-wave voltammetry, showing that the ferrocenyls can separately be oxidized reversibly between −50 and 750 mV (5–7, 9, 12–15: two Fc-related events; 10, 11: six events, being partially superimposed). For complex 10, Ti-centered reversible redox processes appear at −985 (Ti^II/Ti^III) and −520 mV (Ti^III/Ti^IV). Spectro-electrochemical UV-Vis/NIR measurements were carried out on 5, 6, and 12, whereby only 12 showed an IVCT (intervalence charge-transfer) band of considerable strength (ν_max = 6250 cm⁻¹, Δν_½ = 4725 cm⁻¹, ε_max = 240 L·mol⁻¹·cm⁻¹), due to the rigid C₃O₂B cycle, enlarging the coupling strength between the Fc groups. Full article

(This article belongs to the Special Issue Advanced Organic Molecular Electroactive Materials)

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14 pages, 1893 KiB

Open AccessArticle

Sustainable Access to π-Conjugated Molecular Materials via Direct (Hetero)Arylation Reactions in Water and under Air

by Adiel Mauro Calascibetta, Sara Mattiello, Alessandro Sanzone, Irene Facchinetti, Mauro Sassi and Luca Beverina

Molecules 2020, 25(16), 3717; https://doi.org/10.3390/molecules25163717 - 14 Aug 2020

Cited by 11 | Viewed by 2506

Abstract

Direct (hetero)arylation (DHA) is playing a key role in improving the efficiency and atom economy of C–C cross coupling reactions, so has impacts in pharmaceutical and materials chemistry. Current research focuses on further improving the generality, efficiency and selectivity of the method through [...] Read more.

Direct (hetero)arylation (DHA) is playing a key role in improving the efficiency and atom economy of C–C cross coupling reactions, so has impacts in pharmaceutical and materials chemistry. Current research focuses on further improving the generality, efficiency and selectivity of the method through careful tuning of the reaction conditions and the catalytic system. Comparatively fewer studies are dedicated to the replacement of the high-boiling-point organic solvents dominating the field and affecting the overall sustainability of the method. We show herein that the use of a 9:1 v/v emulsion of an aqueous Kolliphor 2 wt% solution while having toluene as the reaction medium enables the preparation of relevant examples of thiophene-containing π-conjugated building blocks in high yield and purity. Full article

(This article belongs to the Special Issue Advanced Organic Molecular Electroactive Materials)

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20 pages, 7459 KiB

Open AccessArticle

Effective Enantiodiscrimination in Electroanalysis Based on a New Inherently Chiral 1,1′-Binaphthyl Selector Directly Synthesizable in Enantiopure Form

by Giorgia Bonetti, Serena Arnaboldi, Sara Grecchi, Giulio Appoloni, Elisabetta Massolo, Sergio Rossi, Rocco Martinazzo, Francesco Orsini, Patrizia R. Mussini and Tiziana Benincori

Molecules 2020, 25(9), 2175; https://doi.org/10.3390/molecules25092175 - 06 May 2020

Cited by 4 | Viewed by 3131

Abstract

Enantioselective electroanalysis, which aims to discriminate the enantiomers of electroactive chiral probes in terms of potential difference, is a very attractive goal. To achieve this, its implementation is being studied for various "inherently chiral" selectors, either at the electrode surface or in the [...] Read more.

Enantioselective electroanalysis, which aims to discriminate the enantiomers of electroactive chiral probes in terms of potential difference, is a very attractive goal. To achieve this, its implementation is being studied for various "inherently chiral" selectors, either at the electrode surface or in the medium, yielding outstanding performance. In this context, the new inherently chiral monomer Naph₂T₄ is introduced, based on a biaromatic atropisomeric core, which is advantageously obtainable in enantiopure form without HPLC separation steps by a synthetic route hinging on enantiopure 2,2’-dibromo-1,1’-binaphthalenes. The antipodes of the new inherently chiral monomer can be easily electrooligomerized, yielding inherently chiral electrode surfaces that perform well in both cyclic voltammetry (CV) enantiodiscrimination tests with pharmaceutically interesting molecules and in magnetoelectrochemistry experiments. Full article

(This article belongs to the Special Issue Advanced Organic Molecular Electroactive Materials)

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