- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Incremental Introduction of Organocatalytic Activity into Conformationally Engineered Porphyrins
摘要： To study the correlation of macrocycle nonplanarity and catalytic activity of free base porphyrins in detail, a series of six tetraphenylporphyrins with graded degree of β-ethyl substitution ('H2EtxTPPs' 1–6; x = 0, 2, 4, 6, 8) was applied in organocatalyzed reactions. They display incrementally increasing nonplanarity due to repulsive peri-interactions. This creates an out-of-plane vector and better accessibility of the core amine and imine groups as the number of alkyl substituents increases. Following such a molecular engineering approach, the inner core system could be used to activate small molecules as a result of significant saddle distortion. The potential organocatalyst 'H2EtxTPPs' were used in benchmark sulfa-Michael reactions and we found a distinct relationship between nonplanarity and conversion. These observations were attributed to the combined effect of enhanced basicity and increased H-bonding potential that could facilitate bifunctional organocatalysis. Ultimately, density functional theory (DFT) calculations were performed on 1–6 to monitor some electronic properties of the title compounds.
关键词： porphyrins,organocatalysis,hydrogen bonds,molecular engineering,macrocycles
更新于2025-09-23 15:22:29
-
Molecular Engineering of Acceptors to Control Aggregation for Optimized Nonfullerene Solar Cells
摘要： Dual molecular engineering on alkyl side chains and halgen accepting ends of asymmetric fused-ring acceptors has been proposed for controlling aggregation to optimized organic solar cells (OSCs). Fluorination or chlorination on end-capped group are explored along with linear octyl (C8) or branched 2-butyl-1-octyl chain (BO) substitution on donating core. The inherent features of larger Cl atom and longer C–Cl bond markedly extend the backbone stacking area and thus enhance molecular aggregation, while bulky BO chain exerts heavier steric shielding effect on backbone stacking. Consequently, IPTBO-4Cl shows properly weakened intermolecular interaction for balanced molecular aggregation. IPTBO-4Cl when blended with PM6 polymer donor delivers a highest power conversion efficiency (PCE) of 15% and with 72.6% fill factor (FF). Expectedly, fluorinated IPT-4F bearing shorter C8 chains outputs a good PCE nearing 15% with 74.2% FF. To the best of our acknowledge, the PCE of 15% is by far the highest for asymmetric FRAs based OSCs. By contrast, IPT-4Cl and IPTBO-4F with either excessively strong or weak aggregation result in relatively low photovoltaic performance. Our results demonstrate controlling aggregation via delicate molecular engineering is an undeniably effective way to achieve efficient OSCs.
关键词： Molecular Engineering,Acceptors,Aggregation,Nonfullerene Solar Cells
更新于2025-09-23 15:19:57
-
Improving Molecular Planarity by Changing Alky Chain Position Enables 12.3% Efficiency All‐Small‐Molecule Organic Solar Cells with Enhanced Carrier Lifetime and Reduced Recombination
摘要： Molecular stacking plays an important role in defining the active layer morphology in all-small-molecule organic solar cells (ASM OSCs). However, the precise control of donor/acceptor stacking to afford optimal phase separation remains challenging. Herein, the molecular stacking of a small-molecule donor is tuned by changing the alky chain position to match a high-performance small-molecule nonfullerene acceptor (NFA), Y6. The alky chain engineering not only affects the planarity of the small-molecule donor, but also the molecular aggregation and the active layer morphology, and thus the photovoltaic performance. Notably, single-junction ASM OSCs with 12.3% power conversion efficiency (PCE) are achieved. The PCE of 12.3% is among the top efficiencies of single-junction ASM OSCs reported in the literature to date. The results highlight the importance of fine-tuning the molecular structure to achieve high-performance ASM OSCs.
关键词： small molecules,molecular engineering,morphology,molecular planarity,organic solar cells
更新于2025-09-19 17:13:59
-
Molecular engineering of a conjugated polymer as a hole transporting layer for versatile p–i–n perovskite solar cells
摘要： Along with the development of perovskite materials, which have enormous potential for optoelectronics such as solar cells and light-emitting diode devices, numerous organic semiconductor polymers, which have been critically adopted into the hole and electron transporting layers, have been synthesized and studied. In neiep-structured perovskite solar cells, various outstanding polymer materials have been successfully applied. However, in peien-structured solar cells, the hydrophobic nature of the polymers makes the sequential deposition of a perovskite thin ?lm dif?cult. Several destructive methods have been proposed; however, a more ef?cacious and fundamental method is urgently needed. Here, we present a nondestructive polymer hole-transporting layer (HTL) thin-?lm formation process based on molecular engineering via a simple solvent process. When we used various solvents with different volatilities, perovskite ?lm formation was achieved on polymer thin ?lms formed from highly volatile solvents. In addition, we elucidated the structure and orientation of the molecules in the ?lms and revealed that the molecular structure of face-on orientation for the horizontally aligned hydrophobic alkyl groups induced a lower surface energy of the ?lm, as determined by grazing-incidence wide-angle X-ray scattering (GIWAXS) measurements. Furthermore, the tilt angle of the molecules, which was calculated from the results of quantitative near-edge X-ray absorption ?ne structure (NEXAFS) analysis, was found to correlate with the surface energy. This result provides guidance for polymer-orientation and surface-energy studies, and perovskite solar cells fabricated using the polymer HTL demonstrated good durability and ?exibility. We expect that our approach represents a new route for fabricating peien-structured solar cells and that numerous valuable p-type conjugated polymers will be developed via our proposed molecular engineering process.
关键词： Solvent process,Organic semiconductor,Flexible device,Conjugated polymer,Perovskite solar cell,Molecular engineering
更新于2025-09-19 17:13:59
-
Macroscopically oriented (3-pentadecyl phenol) dangled fluorene based conductive polymer through side chain engineering for microelectronics
摘要： In this paper, we have designed a solution processable macroscopically oriented conductive polymer of fluorene dangled 3-pentadecylphenol (Polyfluorene pentadecyl benzene, PFLPDB) through side chain engineering and self-assembly approach. Initially fluorene was coupled with 3-pentadecylphenol (3-PDP) and further subjected to oxidative polymerisation in the presence of anhydrous ferric chloride (FeCl3). Effects of polarity of the solvent and time on self-assembly process was studied using various microscopic techniques which suggested the formation of macroscopically oriented fibers having 20–30 nanometer diameter in chloroform with an electrical conductivity of (2.1·10–2 S·cm–1). Optical and electrochemical band gaps were calculated from the studies made by UV-Vis spectroscopy and cyclic voltammetry. Its field effect transfer characteristics were further studied by fabricating an Organic field effect transistor (OFET) device having configuration (Si/SiO2/PFLPDB/Ag) and measured its field effect mobility (1.076 cm2·v–1·s–1) at 1 V and ON/OFF ratio of the device calculated as 1.82·103 suggests its application as an excellent active material for organic microelectronics.
关键词： molecular engineering,macroscopically ordered,3-pentadecyl phenol dangled fluorene,OFET,polymer synthesis
更新于2025-09-16 10:30:52
-
Hybridizing engineering strategy of non-lacunary (nBu4N)4W10O32 by carbon quantum dot with remarkably enhanced visible-light-catalytic oxidation performance
摘要： This paper discloses an e?cient strategy for the preparation of carbon quantum dot (CQD)- hybridized (nBu4N)4W10O32 (TBADT). A key step in this strategy is to hydrothermally treat CQD with TBABr solution to form the TBA+ micelle-encapsulated CQD, which acts as a cationized hybridizer to combine with the W10O32 anion to yield the target catalyst. XPS, UV–vis, PL and CV characterizations indicated that CQD hybridizer plays unique roles in improving the structural stability, redox capacity and visible light response of TBADT, especially in enhancing the stability of its photo-excited state. In the visible light-triggered selective oxidation of cyclohexane, toluene, ethylbenzene and benzyl alcohol with dioxygens in acetonitrile, the optimized hybrid containing 3% CQD shows much higher photo-catalytic activity than pure TBADT, a?ording ca. 21.7% conversion and 84.8% cyclohexanone selectivity in cyclohexane photo-oxidation, Additionally, the additive 2 M HCl further enhances the above hybridization e?ects, thereby signi?cantly promoting the current photo-catalytic oxidations.
关键词： Selective oxidation of organic compounds,Hybridizing molecular engineering,Decatungstates,Molecular oxygen,Carbon quantum dot,Visible-light-catalysis
更新于2025-09-12 10:27:22
-
Effects of oxygen atoms introduced at different positions of non-fullerene acceptors on performance of organic solar cells with poly(3-hexylthiophene)
摘要： With the development of large-area fabrication technologies for organic solar cells (OSCs), poly(3-hexylthiophene) (P3HT) is the best chioce as photovoltaic donor polymer becasue it can be easily synthesized in the scale of kilogram with low cost. However, non-fullerene acceptors (NFAs) matching with P3HT for high performance OSCs are very rare. Herein, by introducing oxygen atoms into the side chains or fused-ring core of indaceno[1,2-b:5,6-b’]dithiophene (IDT), we synthesized two new A2-A1-D-A1-A2 type NFAs, where benzotriazole (BTA) and 2-(1,1-dicyanomethylene)rhodanine (RCN) were used as bridged A1 and terminal A2 respectively. The final NFAs, named as BTA43 and BTA53, show wider absorption spectra and enhanced inter-/intra-molecular interaction in comparison with their analogue BTA3 without oxygen atom. The photovoltaic devices based on P3HT:BTA43 and P3HT:BTA53 can achieve the high PCEs of 6.56% and 6.31% respectively, which are obvious higher than that of BTA3 (5.64%). Our results provide a simple and effective strategy to design promising NFAs to pair with classic photovoltaic polymer P3HT.
关键词： molecular engineering,photovoltaic,non-fullerene acceptors,organic solar cells,P3HT
更新于2025-09-12 10:27:22
-
Structural modification as the pioneer strategy in competition of the porphyrin dye and perovskite solar cells: From dynamics to kinetics of the photovoltaic processes
摘要： Molecular engineering plays a key role in designing ef?cient dye-sensitized/perovskite solar cells (DSSCs/PSCs). Porphyrins have more favorable spectroscopic properties than AZn(COOH)3 perovskites due to their lower chemical hardness. Also, porphyrins are pioneering photosensitizers in exciton formation/dissociation, kinetically. The presence of Zn2t and butadiyne as the linker in the porphyrins and the existence of the electron donors of dimethylammonium and formamidinium in the perovskites improve their photovoltaic properties. Porphyrin dimers have a greater charge transfer distance in comparison to the monomers. However, they show less energy conversion ef?ciency, which may be related to the quenching of the interporphyrin charge transfer. As a consequence, DSSCs based on the porphyrin monomers have a higher ef?ciency than the studied PSCs.
关键词： perovskite solar cells,porphyrin dye,exciton formation/dissociation,molecular engineering,photovoltaic processes
更新于2025-09-11 14:15:04