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Structural, photophysical and electrochemical properties of a novel cardanol-based salophen ligand and its Mn(II) complex
摘要： A new cardanol-based salophen (hpbp) ligand and its manganese complex [Mn(hpbp)] were obtained by microwave-assisted synthesis method, with yields and reaction times of 65% in 20 min and 85% in 5min, respectively. The structural features of compounds were confirmed by electronic (UV-vis and fluorescence), infrared and NMR (1H, 13C) spectroscopic techniques. The photophysical study of the ligand showed ketoenamine-enolimine tautomeric equilibrium, which was discussed based on the excited state intramolecular proton transfer (ESIPT) mechanism and was dependent on the solvent, concentration and molecular structure. The energy of the HOMO and LUMO orbitals (-5.41 and -2.12 eV, respectively), determinated by cyclic voltammetry and UV-Vis, the energy was very close to the values determined by the theoretical calculations. The studies revealed that the hpbp is a tetradentate ligand bonded to the metal ion by phenolic oxygens and by azomethine nitrogens. Therefore, this work contributes to the science of salophen compounds, in addition to stimulating the synthesis of new ligands from renewable sources for the coordination chemistry.
关键词： Cardanol-based salophen,Solvent effect,Manganese complex,Theoretical calculations
更新于2025-11-19 16:46:39
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A Facile Route for NLO Materials: Three-Site Alivolent Substitution Involving One Cation and Two Anions
摘要： Two mixed-metal gallium iodate fluorides, namely, α- and β-Ba2[GaF4(IO3)2](IO3) (1 and 2) have been obtained by the aliovalent substitutions of α- and β-Ba2[VO2F2(IO3)2](IO3) (3 and 4) involving one cationic and two anionic sites. Both of them display large SHG signals (~6 × KDP), large energy bandgaps (4.61 and 4.35 eV), wide transmittance ranges (~0.27-12.5 μm), and large relevant LDTs (29.7 × and 28.3 × AgGaS2, respectively), which indicates that 1 and 2 are potential second-order NLO materials in ultraviolet to mid-infrared. Our studies propose that three-site aliovalent substitution is a facile route for the discovery of good NLO materials.
关键词： aliovalent substitution,hydrothermal synthesis,NLO material,mixed-metal iodate fluoride,theoretical calculations
更新于2025-09-23 15:23:52
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Tuning Hydrogenated Si, Ge, and SiGe Nanocluster Properties Using Theoretical Calculations and a Machine Learning Approach
摘要： There are limited studies available that predict the properties of hydrogenated silicon-germanium (SiGe) clusters. For this purpose, we conducted a computational study of 46 hydrogenated SiGe clusters (SixGeyHz, 1<X+Y≤6) to predict the structural, thermochemical, and electronic properties. The optimized geometries of the SixGeyHz clusters were investigated using quantum chemical calculations and statistical thermodynamics. The clusters contained 6 to 9 fused Si-Si, Ge-Ge, or Si-Ge bonds, i.e., bonds participating in more than one 3- to 4-membered rings, and di?erent degrees of hydrogenation, i.e., the ratio of hydrogen to Si/Ge atoms varied depending on cluster size and degree of multifunctionality. Our studies have established trends in standard enthalpy of formation, standard entropy, and constant pressure heat capacity as a function of cluster composition and structure. A novel bond additivity correction model for SiGe chemistry was regressed from experimental data on 7 acyclic Si/Ge/SiGe species to improve the accuracy of the standard enthalpy of formation predictions. Electronic properties were investigated by analysis of the HOMO–LUMO energy gap to study the effect of elemental composition on the electronic stability of SixGeyHz clusters. These properties will be discussed in the context of tailored nanomaterials design and generalized using a machine learning approach.
关键词： Theoretical Calculations,SiGe Nanocluster,Ge,Machine Learning,Hydrogenated Si,Quantum Chemistry,Spectroscopy,Molecular Structure
更新于2025-09-23 15:21:01
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[Springer Series on Atomic, Optical, and Plasma Physics] Gaseous Ion Mobility, Diffusion, and Reaction Volume 105 || Ab Initio Calculations of Transport Coefficients
摘要： There are two main philosophies behind theoretical calculations. The one illustrated in Chap. 9 is to use models of physical phenomenon, specifically mathematical models, that can be solved exactly, either analytically or by numerical methods. Such models often involve adjustable parameters whose values are fit by comparing model results to experimental values; once the parameters are determined, the models are then used to make similar calculations for other situations, ones that were not part of the set used to determine the parameters. The philosophy illustrated in this chapter is to start from our best theories and, as necessary, make approximations to reduce the equations to forms that are practical to solve, again either analytically or numerically. The hope is that, with time, the approximations will improve such that the calculated values match experimental results without using adjustable parameters. In short, the first philosophy is to make exact calculations with approximate theories, while the second is to make approximate calculations with theories that one believes to be exact.
关键词： experimental results,approximations,mathematical models,adjustable parameters,theoretical calculations
更新于2025-09-23 15:19:57
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Molecular designing of naphthalene diimide based fullerene-free small organic solar cell - Acceptors with high photovoltaic performance by density functional theory
摘要： With the help of computational chemistry tools, three non-fullerene acceptors, which are 2-methylene-malononitrile (M-1), 2-(3-methyl-5-methylene-2-thioxothiazolidin-4-ylidene) malononitrile (M-2) and 1-methyl-5-methylene-2,6-dioxo-1,2,5,6-tetrahydropyridine-3-carbonitrile (M-3), are designed with naphthalene diimide (NDI) central unit. Their different photovoltaic and optoelectronic properties like absorption spectrum, electrons density, solubility strength, reorganization energies, % ETC from donor to acceptor part, excitation energies, oscillating strength, morphology and crystallinity of device for constructing the thin film bulk hetro junction devices were computed at the WB97XD/6-31 G (d, p) level of density functional theory (DFT). Expected open circuit voltages of designed molecules are high as 4.05 eV to 4.49 eV, which are significantly larger than that of the previously reported 3-methyl-5-methylene-2-thioxothiazolidin-4-one (R) with the value of 3.60 eV at the zero current level. Charge carrier mobilities of designed molecules are high due to having low re-organization energies varying from 0.0163 eV to 0.0280 eV for electron and 0.0160 eV to 0.0190 eV for hole, strong absorption properties between the 420 nm to 550 nm in chloroform and 400 nm to 540 nm in gas phase conditions, respectively.
关键词： opto-electronic properties,non-fullerene acceptors,theoretical calculations,dipole moment,organic solar cells,naphthalene di-imide
更新于2025-09-19 17:13:59
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A Photoelectrochemical Study of Bioinspired 2-Styryl-1-Benzopyrylium Cations on TiO2 Nanoparticle Layer for Application in Dye-Sensitized Solar Cells
摘要： In the present work, five 2-styryl-1-benzopyrylium salts and their relative self-assembly processes towards TiO2 nanocrystalline layers were evaluated as photosensitizers in dye-sensitized solar cells (DSSCs). Integration of these 2-styryl-1-benzopyrylium salts with the semiconductor allow for the performance of highly specific functions suitable for smart applications in material science. Spectroscopic and photoelectrochemical measurements conducted on these five bio-inspired dyes, in solution and upon adsorption onto titanium dioxide films, allowed detailed discussion of the anchoring ability of the different donor groups decorating the 2-styryl-1-benzopyrylium core and have demonstrated their ability as photosensitizers. Our results suggest that the introduction of a dimethylamino group in position 4' of the 2-styryl-1-benzopyrylium skeleton can alter the conjugation of the molecule leading to larger absorption in the visible region and a stronger electron injection of the dye into the conduction band of TiO2. Moreover, our experimental data have been supported by theoretical calculations with the aim to study the energy of the excited states of the five compounds. In this specific case, the simulations reported contributed to better describe the properties of the compounds used and to help create the necessary basis for the design of new and targeted bio-inspired molecules.
关键词： molecular synthesis,self-assembly materials,theoretical calculations,anchoring functional group,nanocrystalline layers,benzopyrylium salts,dye-sensitized solar cells
更新于2025-09-16 10:30:52
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[ACS Symposium Series] Fundamentals and Applications of Phosphorus Nanomaterials Volume 1333 || Phosphorus Clusters and Quantum Dots
摘要： Cluster is characterized by its unique role in chemistry and physics due to the fact that it bridges isolated atoms and bulk counterparts. It is also found that the structures and properties of clusters change dramatically with their sizes. Characterized by its diverse bonding patterns, phosphorus clusters have attracted many interests in past years. With the help of laser ablation mass spectrometry and other relative technologies, many kinds of phosphorus clusters have been generated, identified and studied. Their structures and properties are also widely studied by theoretical calculations. This chapter reviews both experimental and theoretical progresses about phosphorus clusters and relative species. On the other hand, the phosphorus quantum dots have attracted a great deal of attention due to its unique structures, properties, and applications in recent years. A quick overview on this topic is also included in the chapter, in order to attract more interests from broad research fields and make a bridge across the cluster study and nanomaterials to benefit scientists in both fields.
关键词： theoretical calculations,laser ablation mass spectrometry,quantum dots,phosphorus clusters,nanomaterials
更新于2025-09-12 10:27:22