Quinacridone Research Articles

Hydrogen bonding-stabilized bipolar organic cathode achieved all-round enhancement in zinc batteries

Bipolar organic small molecules with dual advantages of n/p-type redox reactions can achieve high-capacity-voltage zinc-organic batteries (ZOBs), but are plagued by inevitable dissolution in aqueous electrolytes. Here a hydrogen bonding-stabilized bipolar quinacridone (QA) molecule with synergetic coupling effects of two redox-active centers of n-type carbonyl moieties and p-type amine sites is proposed towards superior ZOBs. Compared with unipolar organics, bipolar QA molecule delivers low-energy-barrier redox kinetics and strong resistance to dissolution in aqueous electrolytes to avoid capacity decay due to the stable H-bond structure and extended π-conjugated aromatic plane. Consequently, Zn||QA battery harvests a high capacity of 212 mAh g−1 at 0.2 A g−1, an outstanding energy density (161 Wh kg−1), along with superior electrochemical stability (20,000 cycles). The high-kinetics hybrid anion-cation two-electron co-coordination mechanism in QA cathode is the root of excellent electrochemical metrics. This study opens novel insights to design multielectron bipolar cathodes for high-performance ZOBs.

Quinacridones as a Building Block for Sustainable Gliding Layers on Ice and Snow.

Quinacridone (QA) and 2,9-dimethylquinacridone (DQA) are synthetic substances suitable as a hard, abrasion-resistant, self-organizing gliding layer on ice and snow. For sustainable use, a large number of parameters must be considered to demonstrate that these non-biogenic substances and their by-products and degradation products are harmless to humans and the environment in the quantities released. For this task, available experimental data are used and supplemented for all tautomers by numerous relevant physical, chemical, toxicological and ecotoxicological estimated values based on various Quantitative Structure Activity Relationship (QSAR) methods. On the one hand, the low solubility of QA and DQA leads to stable gliding layers and thus, low abrasion and uptake by plants, animals and humans. On the other hand, the four hydrogen bond forming functional groups per molecule allow nanoparticle decomposition and enzymatic degradation in natural environments. All available data justify a sustainable use of QA and DQA as a gliding layer. The assessment of the toxicological properties is complemented by an investigation of the size and morphology of DQA particles, as well as field tests indicating excellent performance as a gliding layer on snow.

Directed growth of quinacridone chains on the vicinal Ag(35 1 1) surface.

The formation of self-assembled domains and chains of monomolecular width of quinacridone (QA) on the vicinal Ag(35 1 1) surface was investigated by scanning tunneling microscopy and low-energy electron diffraction. The focus was on the influence of the steps on the QA structures and their preferential azimuthal orientations with the aim of achieving a selective orientation. After deposition at a sample temperature of 300 K, QA forms the same kind of molecular chains as on the nominally flat Ag(100) surface because of strong intermolecular hydrogen bonds, which we reported in a previous publication [Humberg, N.; Bretel, R.; Eslam, A.; Le Moal, E.; Sokolowski, M. J. Phys. Chem. C 2020, 124, 24861-24873]. The vicinal surface leads to one additional chain orientation, which is parallel to the Ag step edges. However, most chains nucleate on the Ag terraces between steps with four distinct azimuthal orientations that are identical to those on Ag(100), and which are determined by the interactions with the (100) surface. At 300 K, the chains grow across the Ag steps, which do not break the azimuthal chain orientations. In contrast, during the deposition at sample temperatures of 400 and 500 K, the nucleation of the chains takes place at the Ag step edges. Hence, these have a strong influence on the azimuthal orientation of the molecules, resulting in a preferential growth of the chains in two of the four azimuthal orientations. We explain this by the adaptation of favorable adsorption sites, which involve the replacement of Ag atoms by QA molecules with specific azimuthal orientations at the step edges.

Biocompatibility assessment of organic semiconductor pigments epindolidione and quinacridone

Organic colorants epindolidione (EPI) and quinacridone (QUI) are commercially available hydrogen-bonded semiconductor pigments. Despite their suitable properties for bioelectronic applications, their biocompatibility has not been thoroughly examined yet. In this study, thin EPI and QUI layers were applied on well plates by vacuum deposition technique followed by short and long-term in vitro biocompatibility study. In vitro testing represents a relatively fast and cheap approach, especially suitable for screening testing and prioritization of materials for further research. LIVE/DEAD assay, cell cycle analysis, adhesion and morphology of NIH 3T3 mouse fibroblasts have been investigated up to 7 days using flow cytometry and fluorescent optical microscopy. In summary, no significant differences were observed in viability, cell morphology, or attachment capabilities between control cells and cells grown on the EPI or QUI surfaces or cells cultivated in medium harvested from EPI- or QUI-coated wells. Our results suggest that both pigments are highly biocompatible. The absence of adverse biological effects of EPI and QUI together with their low cost and availability indicate their high application potential in next-generation bioelectronic devices.

Self-assembled Quinacridone (QA) based polymers with strong hydrogen bonding for OFETs

For totally disordered organic polymer films, charge mobility is low, while the mobility significantly increases if the polymer exhibits self-assembling properties that can be exploited to generate ordered structures. Introducing a hydrogen-bonding functionality in the materials, resulting in hydrogen-bonded material superstructures, can be a suitable method to fulfil those critical requirements. To the best of our knowledge, the chromophores with hydrogen bonding ability are rarely investigated. Quinacridone (QA) with large π-conjugation system, planar structure as well as the amide and carbonyl groups, is attracted our attention. The hydrogen bonding association (NH…OC) can be formed between the amide groups and the carbonyl units from the QA core. In this work, the QA chromophore is, for the first time, introduced as the electron withdrawing unit in donor-acceptor type polymers for semiconductors. The hydrogen bonded polymers exhibit significantly large red shifted up to 192 nm, which indicates that the hydrogen bonding association in the QA system is powerful. In addition, the hydrogen bonding association led to the polymers not only from a disorder state and inferior crystallinity transferring into a more ordered structures with a block- or fiber-liked-shaped crystalline, but also a strong aggregation. This observation is beneficial for the hole transporting between the neighboring molecules. In addition, the HOMO energy levels have been improved after the hydrogen bonding association formation, which is advantage for the Ohmic contact formation. As a consequent, the hole transport mobility is significantly improved from 0.13 cm2 V−1 s−1–1.02 cm2 V−1 s−1. This work demonstrate that QA is a novel and promising electron-deficient building block with potential strong hydrogen bonding association for the high-performance semiconductor.

Synthesis of Soluble Quinacridone Photocatalysts for the Homogeneous Oxidation of Thioethers

AbstractEvaluation of quinacridone (QA) derivatives as homogeneous metal‐free photocatalysts is here presented. QA derivatives were synthetized and systematically characterized, measuring their ground state and excited state redox potentials in dichloromethane (DCM) and 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP), in order to understand how structural modifications influenced their photocatalytic properties. In particular, the effect of dicyanomethylene and nitro EWG groups was investigated, in order to develop a photocatalyst capable of promoting oxidative processes in the presence of molecular oxygen. Among the analyzed derivatives, 2,9‐dinitro‐N,N′‐dibutylquinacridone (DNDBQA) was the one with the highest excited state reduction potential (Ered*=1.60 V in HFIP vs SCE), while N,N’‐dibutylquinacridone (DBQA) showed valuable excited state redox potentials (Ered*=1.29 V; Eox*=−1.28 V in HFIP vs SCE), making it suitable for bimodal applications in oxidative and reductive photocatalytic processes. Afterwards, the synthetized QA derivatives were examined as photocatalysts to promote the selective aerobic oxidation of thioether to sulfoxide. Promising results in thioanisole oxidation were achieved with all the QA derivatives tested as photocatalysts, in terms of yield and selectivity. Remarkably, DBQA showed the best performances, catalyzing the reaction in only 20 minutes, using 0.5 % of the photocatalyst, and showing excellent performances in the oxidation of several thioether derivatives.

Pyrolyzed Organic Pigment as Efficient Surface-Dominated Alkali-Ion Storage Anodes.

Carbonaceous materials have attracted as prospective anodes for rechargeable alkali-ion batteries. In this study, C.I. Pigment Violet 19 (PV19) was utilized as a carbon precursor to fabricate the anodes for alkali-ion batteries. During thermal treatment, the generation of gases from the PV19 precursor triggered a structural rearrangement into nitrogen- and oxygen-containing porous microstructures. The anode materials fabricated from pyrolyzed PV19 at 600 °C (PV19-600) showed outstanding rate performance and stable cycling behavior (554 mAh g-1 over 900 cycles at a current density of 1.0 A g-1) in lithium-ion batteries (LIBs). In addition, PV19-600 anodes exhibited reasonable rate capability and good cycling behavior (200 mAh g-1 after 200 cycles at 0.1 A g-1) in sodium-ion batteries (SIBs). To define the enhanced electrochemical performance of PV19-600 anodes, spectroscopic analyses were employed to reveal the storage mechanism and kinetics of the alkali ions in pyrolyzed PV19 anodes. A surface-dominant process in nitrogen- and oxygen-containing porous structures was found to promote the alkali-ion storage ability of the battery.

Photoelectrochemical C-H Activation Through a Quinacridone Dye Enabling Proton-Coupled Electron Transfer.

Dye-sensitized photoanodes for C-H activation in organic substrates are assembled by vacuum sublimation of a commercially available quinacridone (QNC) dye in the form of nanosized rods onto fluorine-doped tin oxide (FTO), TiO2 , and SnO2 slides. The photoanodes display extended absorption in the visible range (450-600 nm) and ultrafast photoinduced electron injection (<1 ps, as revealed by transient absorption spectroscopy) of the QNC dye into the semiconductor. The proton-coupled electron-transfer reactivity of QNC is exploited for generating a nitrogen-based radical as its oxidized form, which is competent in C-H bond activation. The key reactivity parameter is the bond-dissociation free energy (BDFE) associated with the N⋅/N-H couple in QNC of 80.5±2.3 kcal mol-1 , which enables hydrogen atom abstraction from allylic or benzylic C-H moieties. A photoelectrochemical response is indeed observed for organic substrates characterized by C-H bonds with BDFE below the 80.5 kcal mol-1 threshold, such as γ-terpinene, xanthene, or dihydroanthracene. This work provides a rational, mechanistically oriented route to the design of dye-sensitized photoelectrodes for selective organic transformations.

Longitudinally grown pyrolyzed quinacridones for sodium-ion battery anode

Carbonaceous materials have been actively investigated as anode materials for sodium-ion batteries (SIBs). However, the development of carbonaceous materials that can effectively accommodate large sodium ions within carbon microstructures is highly challenging. In this study, quinacridones (QAs) are used to prepare SIB anode materials via pyrolysis. Among QAs, 2,9-dimethylquinacridone (2,9-DMQA) exhibits prominent morphological development with a high char yield of 61 % at 600 °C. Additionally, we reveal that the pyrolysis mechanism and microstructure are significantly affected by the crystal orientation of the precursor. As the 2,9-DMQA has a parallel-oriented crystal structure, the pyrolyzed 2,9-DMQAs grow polycyclic aromatic hydrocarbons with longitudinal microstructures through thermal polymerization initiated by methyl substituents. In addition, the evolution of gas from the 2,9-DMQA precursor induces the reorganization of the carbon framework to form a disordered structure. The anodes fabricated with the 2,9-DMQA pyrolyzed at 600 °C (2,9-DMQA-600) show sodium-ion storage performance with a high rate capability (290 mAh/g at a current density of 0.05 A/g) and excellent cycle stability (247 mAh/g at 0.1 A/g after 200 cycles and 134 mAh/g at 5 A/g after 1000 cycles). The well-developed carbon microstructures and surface-confined sodium-ion storage derived from the remaining N-containing and O-containing functional groups provide superior electrochemical performance.

Multiple stimuli-responsive electropolymerized polymer based on quinacridone dye via breaking conjugated structure strategy

Quinacridone (QA) dye shows great potential applications in organic optoelectronics owing to the large π-conjugated system, good photothermal stability, and high charge carrier transport behavior. In this work, two quinacridone-based monomers QA-B-CZ and QA-6C-CZ were designed and synthesized, and their polymers pQA-B-CZ and pQA-6C-CZ were prepared by electrochemical polymerization. Both pQA-B-CZ and pQA-6C-CZ exhibit multicolored electrochromic properties at different potentials. It is more intriguing that the pQA-6C-CZ bearing with the flexible long alkyl chain preserves multiple stimuli-responsive characteristics compared to pQA-B-CZ containing benzene unit. pQA-6C-CZ film exhibits reversible and robust acidichromic behavior switched from the initial pink color to purple color, implying its potential as a hydrochloric acid sensor. Besides, pQA-6C-CZ presents reversible orange fluorescence and it disappears in response to electric-/acid-stimulation. The multiple stimuli-responsive behaviors should be ascribed to that the flexible long alkyl chains break the conjugated structure between QA and carbazole, which is beneficial for developing their inherent characters, respectively. The work puts forward a new design strategy for the preparation of multifunctional optoelectronic materials based on QA dye.

Quinacridone based 2D covalent organic frameworks as efficient photocatalysts for aerobic oxidative Povarov reaction

Quinacridone (QA) derivatives, one of cost-effective dyes with intriguing optical activity, have been extensively investigated in many fields such as organic light-emitting diodes, organic solar cells, and photocatalysis. Herein, a new QA-monomer (QA-PCHO) with a zigzag configuration was synthesized via N-arylation of benzene halide and quinacridone. The new monomer could enrich eventual structural diversity of the corresponding covalent organic frameworks (COFs). And based on the precursor, we developed two new QA-based 2D imine COFs with large pore size (> 4.7 nm) which exhibited superior photocatalytic activity toward Povarov reaction with broad substrate scopes and excellent functional group compatibility.

High-performance electrochromic supercapacitor based on quinacridone dye with good specific capacitance, fast switching time and robust stability

• QA dyes were designed and firstly prepared into electrochromic polymers. • The polymers with three donor units show different electrochemical behaviors. • pC10QA-2EDOT film exhibits remarkable electrochromic properties. • The device based on pC10QA-2EDOT exhibits robust cyclic stability. • The electrochromic supercapacitor can make a LED light for more than 85 s. Quinacridone (QA) dye with large π-conjugation system exhibit excellent optical, thermal and chemical properties. A series of QA derivatives (C10QA-2T, C10QA-2EDOT, C10QA-2DT) were designed and synthesized with different donor units (including thiophene, EDOT and bithiophene) in this work. Three monomers show different HOMO energy levels and onset oxidation potentials. Their corresponding polymer films were obtained by electrochemical polymerization. Compared to pC10QA-2T and pC10QA-2DT, pC10QA-2EDOT exhibits better integrated electrochromic properties in terms of multicolor showing (yellow, gray and blue), higher optical contrast (more than 40% in the visible region), larger coloration efficiency (498 cm 2 /C at 455 nm), faster switching time (less than 1 s) and better cyclic stability. It is intriguing that the electrochromic device based on pC10QA-2EDOT exhibits robust stability over 50,000 cycles with almost no decay of its original optical contrast. In addition, pC10QA-2EDOT film possesses large volume specific capacitance of up to 322 F/cm 3 , which should be ascribed to that the loose and porous structures owing to large dihedral angles caused by the steric hindrance of oxygen on the EDOT may facilitate the ion diffusion during the doping/dedoping process. Hence, the electrochromic supercapacitor can supply power to a green LED for 85 s. This work pioneers QA dye in the electrochromic field and further develops a new electrochromic energy storage device with visual color display, which may have potential prospects in portable and wearable electronic devices.

Quinacridone-based small molecule acceptor as a third component in ternary organic solar cells

• A novel electron-accepting quinacridone derivative was used as a core of the acceptor. • The new acceptor CN-QA-RH presented a broad absorption in the solar spectrum and high crystallinity. • The ternary OSCs based on PBDB-T:PC 71 BM:CN-QA-RH demonstrated the PCE of 19.13% under LED (6500 K) illumination at 1000 lx. Ternary blend strategy has exhibited great prospect in organic solar cells (OSCs) due to the potential to boost the power conversion efficiency (PCE) by mainly enhancing the light absorption and morphology of the active layer. In particular, introduction of non-fullerene acceptor as the third component can overcome the intrinsic shortages of fullerene in the binary fullerene OSCs. Herein, an acceptor–donor-acceptor’-donor–acceptor(A-D-A’-D-A) type molecule, CN-QA-RH, containing a rigid acceptor unit quinacridone (QA) derivative as a central core, is designed and synthesized. The compound exhibits a wide absorption in the solar spectrum and good crystallinity. Both absorption and morphology of the active layer were improved by incorporating CN-QA-RH as the third component into PBDB-T:PC 71 BM. As a result, the best PCE of the ternary OSCs based on PBDB-T:PC 71 BM:CN-QA-RH was 8.96% while the binary OSCs based on PBDB-T:CN-QA-RH and PBDB-T:PC 71 BM exhibited PCEs of 2.66% and 7.84%, respectively. Moreover, the optimized ternary OSCs yielded a PCE of 19.13% under LED illumination at 1000 lx. Therefore, QA derivatives can be applied as non-fullerene acceptors with wide absorption and high crystallinity and demonstrated a great potential as the third component to construct highly efficient ternary OSCs for indoor light.

Electronic and photovoltaic properties of triphenylamine-based molecules with D-π-A-A structures

Four organic dyes (AP25, AP26, AP27, and AP28) with triphenylamine (T) as a donor coupled with different bridge groups of cyclopentadithiophene (CPDT) and quinacridone (QA), the auxiliary acceptor groups thienothiophene (TT) and benzothiadiazole (BTZ), are theoretically investigated in this paper for dye-sensitized solar cells (DSSC). DFT is used to calculate the ground-state properties of dyes, and TDDFT provides an understanding of the excited-state properties of dyes. The parameters affecting photoelectric conversion efficiency (PCE) of DSSC, correlating with Voc and Jsc were calculated to compare the photovoltaic performance of investigated dyes. Among those dyes, the results show that AP27 molecule has better photoelectric properties due to redshift absorption spectrum, larger LHE, longer fluorescent lifetime (τ1) and excited-state lifetime (τ2), and the higher μnormal. These results suggest that the CPDT-bridge linked with BTZ auxiliary acceptor is a promising design to develop PCE on DSSC.

Pure organic quinacridone dyes as dual sensitizers in tandem photoelectrochemical cells for unassisted total water splitting.

Pure organic dye QAP-C8 based on quinacridone (QA) with octyl side chains as the donor and pyridine dicarboxylic acid (PDA) as the acceptor was first used in both the photoanode and the photocathode of photoelectrochemical cells. A tandem device with QAP-C8 as the photosensitizer realized overall water splitting and showed a STH of 0.11% under neutral pH conditions without an external bias.

Highly Efficient and Stable Perovskite Solar Cells Enabled by Low‐Cost Industrial Organic Pigment Coating

AbstractSurface passivation of perovskite solar cells (PSCs) using a low‐cost industrial organic pigment quinacridone (QA) is presented. The procedure involves solution processing a soluble derivative of QA, N,N‐bis(tert‐butyloxycarbonyl)‐quinacridone (TBOC‐QA), followed by thermal annealing to convert TBOC‐QA into insoluble QA. With halide perovskite thin films coated by QA, PSCs based on methylammonium lead iodide (MAPbI3) showed significantly improved performance with remarkable stability. A PCE of 21.1 % was achieved, which is much higher than 18.9 % recorded for the unmodified devices. The QA coating with exceptional insolubility and hydrophobicity also led to greatly enhanced contact angle from 35.6° for the pristine MAPbI3 thin films to 77.2° for QA coated MAPbI3 thin films. The stability of QA passivated MAPbI3 perovskite thin films and PSCs were significantly enhanced, retaining about 90 % of the initial efficiencies after more than 1000 hours storage under ambient conditions.

Highly Efficient and Stable Perovskite Solar Cells Enabled by Low-Cost Industrial Organic Pigment Coating.

Surface passivation of perovskite solar cells (PSCs) using a low-cost industrial organic pigment quinacridone (QA) is presented. The procedure involves solution processing a soluble derivative of QA, N,N-bis(tert-butyloxycarbonyl)-quinacridone (TBOC-QA), followed by thermal annealing to convert TBOC-QA into insoluble QA. With halide perovskite thin films coated by QA, PSCs based on methylammonium lead iodide (MAPbI3 ) showed significantly improved performance with remarkable stability. A PCE of 21.1 % was achieved, which is much higher than 18.9 % recorded for the unmodified devices. The QA coating with exceptional insolubility and hydrophobicity also led to greatly enhanced contact angle from 35.6° for the pristine MAPbI3 thin films to 77.2° for QA coated MAPbI3 thin films. The stability of QA passivated MAPbI3 perovskite thin films and PSCs were significantly enhanced, retaining about 90 % of the initial efficiencies after more than 1000 hours storage under ambient conditions.

Hydrogen-Bonded One-Dimensional Chains of Quinacridone on Ag(100) and Cu(111): The Role of Chirality and Surface Bonding

The adsorption and ordering of the prochiral molecule quinacridone (QA) on the Ag(100) and Cu(111) surfaces were studied by low-energy electron diffraction and scanning tunneling microscopy. Upon adsorption, the molecules form parallel homochiral chains of flat-lying molecules linked together via hydrogen bonds on both surfaces, but these chains show significant surface-dependent differences concerning their lateral order. On both substrates, the chains are not thermodynamically stable but only metastable and stabilized by kinetic barriers. On the Ag(100) surface, annealing induces a phase transition to a highly ordered and heterochiral structure with a reduced density of hydrogen bonds. The related loss of bonding energy is overcompensated by a stronger bonding to the substrate, yielding a commensurate structure. For QA on Ag(100), we propose that during the initial chain formation and the phase transition upon annealing, the molecules can change their handedness by rotating around their long axes. In contrast, the initial chain formation and the phase transitions of QA on the Cu(111) surface appear to be subject to stronger kinetic limitations. These are explained by stronger substrate molecule interactions on Cu(111), which reduce the diffusion and the possibility for a change of handedness in comparison to QA on Ag(100). We discuss how the intermolecular hydrogen bonds, the 2D chirality, and the different chemical reactivities of the two surfaces [Ag(100) and Cu(111)] influence the structural formation of QA aggregates. We compare our results to the results for QA on Ag(111) reported previously by Wagner et al. [JPCC 2014, 118, 10911-10920].

Photocatalytic Reduction of CO2 to CO over Quinacridone/BiVO4 Nanocomposites.

Solar energy-driven photoreduction of CO2 to energy-rich chemicals is of significance for sustainable development but challenging. Herein, quinacridone (QA)/nBiVO4 (n=0.2-20, in which n stands for the mass ratio of BiVO4 to QA) nanocomposites were developed for photoreduction of CO2 . Characterization of the materials with Fourier-transform (FT)IR spectroscopy and X-ray photoelectron spectroscopy (XPS) pointed to QA/nBiVO4 preparation via hydrogen-bonding-directed self-assembly of QA on BiVO4 nanosheets. Using triethanolamine (TEOA) as a sacrifice reagent, QA/10BiVO4 showed the best performance, affording CO with a production rate of 407 μmol g-1 h-1 , 24 times higher than those of pure QA. It was indicated that the Z-scheme charge-transfer mechanism of QA/nBiVO4 could significantly improve the separation and transmission efficiency of photo-generated electrons and holes. This novel approach provides new insight for fabricating the composite photocatalytic materials of small molecule organic semiconductors and inorganic semiconductors with high efficiency for photocatalytic of reduction CO2 .

Quinacridone skeleton as a promising efficient leveler for smooth and conformal copper electrodeposition

Superconformal copper electrodeposition of nano-micro printed circuit board (PCB) is of prime importance in microelectronics manufacturing. It is very challenging and still remains deficient exploration to fully realize efficient conformal electrodeposition in the emerging organic additives. Herein, a family of quinacridone (QA) derivatives bearing quaternary ammonium groups were synthesized via two steps with high yields. These compounds were functionalized as promising levelers for superconformal Cu deposition for the first time. Alkyl chains and aryl groups tuning strategies were performed to precisely synthesize and optimize these QA levelers. The optimal leveling agent (DCQA-C8-QAS) and electrodeposition formula were obtained through electrochemical measurements, theoretical calculations and through-hole (TH) electrodeposition experiments. The superior leveling behavior of DCQA-C8-QAS was mainly attributed to the strong interaction and adhesion ability towards copper surface, which were verified by X-ray photoelectron spectra (XPS), atomic force microscope (AFM) and contact angle detection (CA).