JOURNAL OF MOLECULAR STRUCTURE
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2025
·
IF 4.7
Chen-Yuan Ma,Yu-Ming Pan,Pei Han,Mei-Hong Duan
Development of new birefringent crystals with enhanced properties remains an ongoing research priority. Through the exploration of guanidinium-containing oxalates with the structural modulation of Pb 2+ and Cl - , a new birefringent crystal, [C(NH 2 ) 3 ]Pb(C 2 O 4 )Cl·H 2 O (GPCCH), was successfully obtained. GPCCH was characterized by two types of π-conjugated building units, which contributes to the coexistence of a wide bandgap of 3.98 eV and a large birefringence of 0.24@546 nm. These findings highlight the synergistic role of π-conjugated building units and partially-chlorinated lead-containing units played in generating fascinating UV birefringent crystals.
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DYES AND PIGMENTS
·
2017
·
IF 3.473
Liang-Wei Ma,Zu-Sheng Huang,Sheng Wang,Herbert Meier,Derong Cao
Three novel quinoxaline-based donor-π-acceptor type organic dyes were synthesized and explored as sensitizers in dye-sensitized solar cells (DSSCs). The impacts of various π-conjugation configurations which contain different quinoxaline derivatives on the absorption properties , electrochemical properties and photovoltaic performances , as well as theoretical calculations have been investigated systematically. The photovoltaic performances of these dyes were found to be highly relevant to the π-conjugated configurations. In particular, the DSSC based on the dye with 2,3-dioctylquinoxaline as the spacer exhibited the highest efficiency of 8.20% with a short-circuit photocurrent density of 17.83 mA cm −2 , an open-circuit photovoltage of 0.71 V, and a fill factor of 0.65, under standard global AM 1.5G solar light condition. However, the DSSC based on the dye with a more conjugated dithieno [2,3- a :3′,2′- c ]phenazine core as the spacer exhibited a lower efficiency due to serious intermolecular aggregation. When the intermolecular aggregation is inhibited, the efficiency can be improved greatly. The results confirm that the configuration of the π-conjugation of the dyes should be considered for the improvement of the photovoltaic performance.
研究领域:
材料科学
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光伏技术
·
有机化学
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高影响因子
JOURNAL OF POWER SOURCES
·
2019
·
IF 7.467
Li Yang,Wenxuan Wei,Yuanchi Ma,Yewei Xu,Guanjun Chang
The design and synthesis of novel π-conjugated polymers receive tremendous attention in electrochemical energy storage . We report a lithium-doped crosslinked π-conjugated polymer, PTAT@LiCl, with excellent electrochemical performance as an anode material for lithium ion batteries (LIBs). Benefiting from a wider range of intermolecular channel caused by cation-π interaction inducing lithium ion insert into polymer network , the prepared PTAT@LiCl shows high capacity (892 mAh g −1 , 100 mA g −1 ), excellent rate performance (200 mAh g −1 , 4C), and outstanding cycle life (500 cycles). This work provides a new insight into the performance enhancement of organic LIBs through noncovalent cation-π (Li + -π) interaction between lithium ions and large π-conjugated aromatic ring , which are meaningful for the potential application of LIBs.
研究领域:
材料科学
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能源存储
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高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Ruzhen Cheng,Run Zou,Long He,Lei Liu,Chang Cao,Xinyuan Li,Xuhong Guo,Jun Xu
The precipitation and deposition of asphaltenes often cause great troubles to the recovery and transportation of crude oil. Adding polymer inhibitors is an effective approach to prevent asphaltenes from clogging. In this study, maleic anhydride-co-octadecene copolymers with imidazolyl, phenyl, and pyridyl pendants were synthesized. The inhibition behaviors of two extracted asphaltenes in the presence of these copolymers were investigated, which were also identified by the rheological tests of the heavy crude oil sample. The chemical structure of both asphaltenes was analyzed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), elemental analysis, and time-of-flight (TOF) spectrometry. Both asphaltenes A and B have a high aromaticity and low H/C. However, asphaltene B has a much higher aromaticity and polarity than that of asphaltene A. Ultraviolet–visible spectroscopy, turbidity meter, and dynamic light scattering (DLS) were employed to determine the precipitation behaviors of asphaltenes in the absence and presence of copolymers. The influence of intrinsic properties of asphaltenes, polymer concentration, and aromatic group grafting ratio on asphaltene precipitation were also compared. It is found that the initial precipitation point (IPP) of both asphaltenes is increased most by the copolymer containing 2-aminopyridine (PMO-2-P), while the copolymer containing N-(3-aminopropyl)imidazole (PMO-I) shows the worst inhibition performance. It is because that pyridine group has a stronger adsorption capacity with asphaltene than the imidazole group. The effect of various functional groups in copolymers on inhibiting asphaltene precipitation conforms to the following sequence: 2-aminopyridine > aniline > 4-aminopyridine > N-(3-aminopropyl)imidazole. It is also found that high polymer concentration and grafting ratio are beneficial to inhibit the asphaltene precipitation. As a result of the π–π conjugation and hydrogen-bonding attractions between the aromatic groups in the copolymers and the asphaltenes, the polymers can be stably adsorbed onto the surface of the asphaltenes and prevent their aggregation.
研究领域:
石油化学
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胶体化学
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 47
·22335-22343
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IF 3.591
Siqi Wei,Haoyi Li,Xinghang Yin,Qiang Yang,Anli Chen,Renjie Li,Jing Wang,Rui Yang
Synthesizing high-efficiency red carbon dots (R-CDs) and exploring their photoluminescence mechanism remain challenges as well as critical issues hindering the development of red room-temperature phosphorescence (RTP) materials of CDs. Herein, a series of highly efficient R-CDs are prepared from citric acid and formamide by solvothermal method on account of the protective and destructive effects of solvents. The larger sp2 conjugated domains of the carbon core and the high content of graphitic N are identified as the key factors for R-CDs to exhibit red fluorescence. Surface groups also contribute to red emission by means of the formation of the N, O-related defect state. By establishing N-doping models and using DFT calculation, it is further demonstrated that the strong p–π conjugation effect caused by the non-bonding electrons of graphitic N would facilitate HOMO–LUMO splitting of the carbon core, thus leading to a significant decrease in the HOMO–LUMO gap. Energy level splitting could lead to a certain degree of energy level crossing, which could contribute to effective intersystem crossing and produce red RTP. From this, the potential applications of R-CDs in the information encryption field are proposed and demonstrated.
研究领域:
材料科学
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光电技术
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纳米技术
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化学
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高影响因子
LUMINESCENCE
·
2021
·Vol. 37
·期 2
·247-254
·
IF 2.464
Qian Cheng,Zhiyuan Chen,Qing Zhang,Senqiang Zhu,Rui Liu,Hongjun Zhu
Three A–π–A or D–π–D perylene diimide ( PDI ) derivatives with varied groups on π-conjugate were synthesized and characterized. The photophysical properties of these compounds were systematically studied by spectral experiments and density functional theory calculations. All compounds displayed intense absorption bands at 300–800 nm wavelengths. However, diverse groups on the π-conjugate influenced the UV–vis absorption. Electron-withdrawing groups on PDI-2 caused a slight red shift at the 350–400 nm wavelength and a blue shift after 400 nm wavelength. At the same time, the electron-donating substituents on PDI-3 caused an obvious red shift of this band. These PDI derivatives exhibited emission in solution at room temperature (λ em = 500–850 nm). The quantum yield of PDI-3 decreased, while the electron-donating substituents were introduced to the π-conjugated motifs. However, the quantum yield of PDI-2 increased when electron-withdrawing substituents were introduced to the π-conjugated motifs. In addition, PDI-1 and PDI-2 exhibited broad triplet transient absorption in the visible region. These photophysical properties could help us to understand the relationship between structure and photophysical properties of perylene diimide derivatives and exploit more original perylene diimide-based optical functional materials.
研究领域:
材料化学
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光物理学
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DOI
PubMed
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-10
·
IF 17.694
Wang Qiyou,Liu Kang,Hu Kangman,Cai Chao,Li Huangjingwei,Li Hongmei,Herran Matias,Lu Ying-Rui,Chan Ting-Shan,Ma Chao,Fu Junwei,Zhang Shiguo,Liang Ying,Cortés Emiliano,Liu Min
Atomically dispersed transition metals on carbon-based aromatic substrates are an emerging class of electrocatalysts for the electroreduction of CO 2 . However, electron delocalization of the metal site with the carbon support via d-π conjugation strongly hinders CO 2 activation at the active metal centers. Herein, we introduce a strategy to attenuate the d-π conjugation at single Ni atomic sites by functionalizing the support with cyano moieties. In situ attenuated total reflection infrared spectroscopy and theoretical calculations demonstrate that this strategy increases the electron density around the metal centers and facilitates CO 2 activation. As a result, for the electroreduction of CO 2 to CO in aqueous KHCO 3 electrolyte, the cyano-modified catalyst exhibits a turnover frequency of ~22,000 per hour at −1.178 V versus the reversible hydrogen electrode (RHE) and maintains a Faradaic efficiency (FE) above 90% even with a CO 2 concentration of only 30% in an H-type cell. In a flow cell under pure CO 2 at −0.93 V versus RHE the cyano-modified catalyst enables a current density of −300 mA/cm 2 with a FE above 90%.
研究领域:
催化化学
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电化学
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材料科学
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PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Shucheng Liu,Ming Li,Yi Tang,Xiaogang Wen
A novel Fe 3 O 4 /MgAl-TA LDH (FTLDH) nanocomposites with tartrate anion-intercalation is successfully synthesized by a one-step hydrothermal process. The synthesized FTLDH are flower-like hollow microspheres composed of nanosheets with an average thickness of 25 nm. The specific surface area of the calcined FTLDH (FTLDH-C) greatly increases to 120 m 2 /g, exposing more adsorption sites which can bind the target adsorbates. The adsorption capacities of obtained hollow microspheres towards Congo Red (CR), Malachite Green (MG) and Neutral Red (NR) can reach 1520, 819 and 929 mg/g at room temperature, 2590, 1041 and 1153 mg/g at 45 °C, receptively. The excellent dye adsorption performance can be attributed to the unique hollow and porous microstructure, trumpet-shaped through channels in shell layer and high specific surface area. The dye adsorption process on FTLDH-C hollow microsphere is in accordance with Langmuir isotherm and pseudo-second-order kinetic models. The adsorption is mainly driven by electrostatic attraction (CR) and the hydrogen bonds/π-π conjugation etc. chemical interaction (CR, MG, NR etc.) between dye molecules and LDH nanoflakes. Due to the presence of magnetic Fe 3 O 4 nanoparticles in the nanocomposites, the used adsorbent can be easily recollected with magnetic field. This study puts forward a new way to develop high-performance adsorbent via microstrucure-design and magnetic functionalization.
研究领域:
环境科学
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材料科学
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高影响因子
Inorganic Chemistry Frontiers
·
2023
·Vol. 10
·期 20
·5979-5985
·
IF 7
Xiaoguang Du,Fangyan Wang,Fei Liang,Zhanggui Hu,Yicheng Wu,Xinyuan Zhang
Nonlinear optical (NLO) crystals are the core components of high-performance coherent sources. Their properties can be modulated and improved by molecular design of constituent functional motifs. In this study, inspired by a classical π-conjugated borate group (B3O6)3−, we discovered a π-conjugated isocyamelurate [H2C6N7O3]− anion with colossal π-conjugated orbitals, thus giving ultra-strong anisotropic first-order polarizability and ultralarge second-order susceptibility. Two new alkaline-earth metal isocyamelurates, namely, Ca0.5H2C6N7O3·4H2O (I) and Sr0.5H2C6N7O3·4H2O (II), were successfully synthesized by a facile aqueous solution method. Both I and II show excellent nonlinear optical properties, including wide band gap (>4.05 eV), large birefringence (Δn ∼ 0.24), and a strong second order harmonic generation response (>5 × KDP). Moreover, I and II exhibit a broadband ultraviolet photoluminescence around 400 nm, which indicate that they are potential multifunctional optical materials with photon-emission and photon-conversion properties. The first-principles calculations reveal that the (H2C6N7O3)− anionic group plays a dominant role in optimizing and enhancing the optical performance of the crystals. This study confirms that there are plenty of opportunities for (iso)-cyamelurates in designing functional crystals with superior properties.
研究领域:
材料科学
·
光学
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高影响因子
DIAMOND AND RELATED MATERIALS
·
2021
·
IF 3.315
Wei Jiang,Pinghua Chen,Xueqin Li,Guanghui Wu,Huitao Zheng,Chenxuan Li,Lei Fang,Hualin Jiang
Electrochemical analysis using specifically designed electrodes represents a promising strategy to detect organic pollutants, such as 4-nitrophenol (4-NP), in the environment. Towards this goal, a metal-free composite of phenanthroline doped graphitic carbon nitride (g-C 3 N 4 -PD) was synthesized, characterized, and applied as the electrode materials for electrochemical detection of 4-NP in water. The phenanthroline doping simultaneously extends the π-conjugation system of g-C 3 N 4 , and creates defect sites in g-C 3 N 4 , leading to better conductivity, higher 4-NP adsorption, and significantly enhanced electrocatalytic activity . Electrochemical sensors were fabricated by using g-C 3 N 4 -PD-modified carbon electrode. They showed a broad detection concentration range of 2.854–1117 μM and a low detection limit of 39 nM for 4-NP, with high reproducibility, stability and selectivity . Reliable and accurate measurements of 4-NP in real-life water samples have been demonstrated using these electrodes.
研究领域:
环境科学
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材料科学
·
分析化学
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Qingqing Liu,Lan Zhou,Yuhua Zeng,Qiaolan Fang,Xing Deng,Wenzhou Zhong,Liqiu Mao
Developing low-cost and efficient metal-free carbon-based photocatalysts is of great significance but remains a challenge for light-driven selective organic synthesis integrated with CO 2 reduction. Herein, the N/O functional groups and high specific surface areas of porous biochars are dexterously designed by one-pot pyrolysis of waste coconut shell with combining tripolycyanamide and K 2 CO 3 co-modification, and demonstrate the high performance of the obtained porous biomass-derived biochar photocatalysts with photogenerated holes and electrons on the synergistic coupling amine dehydrogenation oxidation and reaction of CO 2 reduction to HCOOH, which can swiftly convert 86.0 % of benzylamine into N-benzylidenebenzylamine with a selectivity of 99.9 % under visible-light radiation. This coconut shell-derived biochar exhibits a wide generality for various aromatic amines, accompanied by the advantages of good recyclability and stability. Structure analysis and theoretical calculations reveal that the construction of the orbital interaction between the p-orbital on nitrogen and π-orbitals of polyaromatics with the terminal carboxylic acid groups greatly boosts the photogenerated charge-carrier separation, and reduce the possibility of recombination of photogenerated electrons and holes along with the layered graphitic structure. Meanwhile, the polyaromatic carboxylic acid groups and graphitic-N moieties serve as active sites with the π-π electron-donor-acceptor interactions for the adsorption/activation of amines and CO 2 , which promotes the synergistic oxidation-reduction process.
研究领域:
材料科学
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环境科学
·
有机化学
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高影响因子
Small
·
2024
·Vol. 20
·期 37
·2400549
·
IF 13
Yaoguo Shen,Mingliang Ding,Gang Chen,Yingjie Luo,Sangen Zhao,Junhua Luo
A large optical anisotropy is the most important parameter of birefringent crystals. Integrating π-conjugated groups with large polarizable anisotropy into target compounds is a common strategy for constructing brilliant birefringent crystals. However, the key problem is to enhance the density of the birefringence-active units and further arrange them parallelly. In this study, three novel birefringent crystals, C 9 H 7 NBrX (X = Cl, Br, NO 3 ), are successfully synthesized by introducing a new birefringence-active [C 9 H 7 NBr] + unit. Interestingly, these compounds feature similar layered structures but exhibit different optical anisotropies at 550 nm (0.277 for C 9 H 7 NBrCl, 0.328 for C 9 H 7 NBrBr, and 0.401 for C 9 H 7 NBrNO 3 ) owing to the different anions in them. Particularly, the small trigonal planar NO 3 anions perfectly fill the interstices of the π-conjugated [C 9 H 7 NBr] + groups with large optical anisotropy, with the resulting compound C 9 H 7 NBrNO 3 showing superior optical properties compared to the others. The above findings provide strategies for designing new optical materials with large birefringence by matching birefringence-active groups of different sizes. Additionally, a new theory for predicting and comparing the polarizability anisotropy of compounds is proposed, which would guide in exploring large birefringent crystals.
研究领域:
材料科学
·
光学
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PubMed
高影响因子
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