Computer-aided design of formulated products

Formulated products represent a particular class of complex chemical products, and their design is typically based on experience and extensive experimentation. Although still at an early stage, and despite that their potential is not fully accessed and not fully used by the industry, computer-aided design (CAD) methods and tools offer many possibilities in the design of formulated products. The CAD methodology based on computerized models enables the formulation chemists to speed up the design process, without completely replacing experiments.In this work, we summarize previous studies in the field and present important elements of the CAD framework, emphasizing estimation methods for key target properties, link to specifications, and finally, some case studies will illustrate how the CAD framework can be used in practice for formulated products.     

Metal–Organic Framework (MOF)-Derived Carbon-Mediated Interfacial Reaction for the Synthesis of CeO2−MnO2 Catalysts

CeO₂-based catalysts are widely studied in catalysis fields. Developing one novel synthetic approach to increase the intimate contact between CeO₂ and secondary species is of particular importance for enhancing catalytic activities. Herein, an interfacial reaction between metal–organic framework (MOF)-derived carbon and KMnO₄ to synthesize CeO₂−MnO₂, in which carbon is derived from the pyrolysis of Ce-MOFs under an inert atmosphere, is described. The MOF-derived carbon is found to restrain the growth of CeO₂ crystallites under a high calcination temperature and, more importantly, intimate contact within CeO₂/C is conveyed to CeO₂/MnO₂ after the interfacial reaction; this is responsible for the high catalytic activity of CeO₂−MnO₂ towards CO oxidation.     

Synergistic Surface Passivation of CH3NH3PbBr3 Perovskite Quantum Dots with Phosphonic Acid and (3-Aminopropyl)triethoxysilane

CH₃NH₃PbBr₃ perovskite quantum dots (PQDs) are synthesized by using four different linear alkyl phosphonic acids (PAs) in conjunction with (3-aminopropyl)triethoxysilane (APTES) as capping ligands. The resultant PQDs are characterized by means of XRD, TEM, Raman spectroscopy, FTIR spectroscopy, UV/Vis, photoluminescence (PL), time-resolved PL, and X-ray photoelectron spectroscopy (XPS). PA chain length is shown to control the PQD size (ca. 2.9–4.2 nm) and excitonic absorption band positions (λ=488–525 nm), with shorter chain lengths corresponding to smaller sizes and bluer absorptions. All samples show a high PL quantum yield (ca. 46–83 %) and high PL stability; this is indicative of a low density of band gap trap states and effective surface passivation. Stability is higher for smaller PQDs; this is attributed to better passivation due to better solubility and less steric hindrance of the shorter PA ligands. Based on the FTIR, Raman, and XPS results, it is proposed that Pb²⁺ and CH₃NH₃⁺ surface defects are passivated by R−PO₃²⁻ or R−PO₂(OH)⁻, whereas Br⁻ surface defects are passivated by R−NH₃⁺ moieties. This study establishes the combination of PA and APTES ligands as a highly effective dual passivation system for the synergistic passivation of multiple surface defects of PQDs through primarily ionic bonding.     

Inorganic Molecular Electride Mg4O3: Structure,Bonding, and Nonlinear Optical Properties

Growing demands of material science and, in particular, in the field of nonlinear optics (NLO) encourage us to look for stable highly polarizable molecules with excess diffuse electrons. An unusual class of compounds called electrides comply with these requirements. Many attempts have been made, yet only few electrides have been synthesized as solids and none of them as molecular species. In this paper, a new theoretically designed molecular species with electride characteristics is reported. The idea of this molecular electride comes from the formation of electride-like features in the MgO crystal with defect F-centers. The geometry of the investigated molecule can be described as a Mg₄O₄ cube with one oxygen atom removed. In Mg₄O₃, two 3s electrons are pushed out from the inner area of the molecule forming a diffuse electride multicentered bond. Our calculations show that this electride-like cluster possesses a noticeably large first hyperpolarizability β=5733 au. At the same time, a complete cube Mg₄O₄ and Mg₄O₃²⁺ without electride electron pair have much smaller β: 0 au and 741 au, respectively. This fact indicates the decisive role of the electride electron pair in NLO properties. Additionally, vertical detachment energies of isomers (VDE), excitation energies ΔE, polarizabilities α, and IR spectra were calculated. These properties, including β, are supposed to be observable experimentally and can serve as indirect evidence of the stable molecular electride formation.     

Bis-tridentate IrIII Phosphors Bearing Two Fused Five-Six-Membered Metallacycles: A Strategy to Improved Photostability of Blue Emitters

Iridium complexes bearing chelating cyclometalates are popular choices as dopant emitters in the fabrication of organic light-emitting diodes (OLEDs). In this contribution, we report a series of blue-emitting, bis-tridentate Ir^III complexes bearing chelates with two fused five-six-membered metallacycles, which are in sharp contrast to the traditional designs of tridentate chelates that form the alternative, fused five-five metallacycles. Five Ir^III complexes, Px-21 – 23 , Cz-4 , and Cz-5 , have been synthesized that contain a coordinated dicarbene pincer chelate incorporating a methylene spacer and a dianionic chromophoric chelate possessing either a phenoxy or carbazolyl appendage to tune the coordination arrangement. All these tridentate chelates afford peripheral ligand–metal–ligand bite angles of 166–170°, which are larger than the typical bite angle of 153–155° observed for their five-five-coordinated tridentate counterparts, thereby leading to reduced geometrical distortion in the octahedral frameworks. Photophysical measurements and TD-DFT studies verified the inherent transition characteristics that give rise to high emission efficiency, and photodegradation experiments confirmed the improved stability in comparison with the benchmark fac-[Ir(ppy)₃] in degassed toluene at room temperature. Phosphorescent OLED devices were also fabricated, among which the carbazolyl-functionalized emitter Cz-5 exhibited the best performance among all the studied bis-tridentate phosphors, showing a maximum external quantum efficiency (EQE_max) of 18.7 % and CIE_x,y coordinates of (0.145, 0.218), with a slightly reduced EQE of 13.7 % at 100 cd m⁻² due to efficiency roll-off.     

科研成果向教学实验的转化设计与实践成效*

围绕学校高水平应用型人才培养目标,依托省级重点实验室与省级化学化工大学生创新训练中心等科研教学平台,将“零排放型化学镀镍及其废液资源化为掺杂型LiFePO₄/C复合材料”的科研成果进行拆解和提炼,设计为分阶段、多层次的10个教学实验项目,并予以实践。结果表明,该科教融合模式营造出良好的科研氛围,有利于学生科研素养与创新意识的培养、实践能力与创新能力的提升。     

基于线性规划的高温超导磁体线圈设计方法

电子真空回旋器件是一种对磁场精度要求较高的微波源装置, 一般采用超导磁体提供磁场环境. 超导磁体的应用中, 磁场分布的实现是超导磁体设计的核心问题. 提供回旋器件磁场的高温超导磁体包含较复杂的磁体绕组, 为了解决此类设计计算问题, 本文提出了一种包含设计区域约束的线性优化方法进行回旋器件高温超导绕组的设计优化, 通过分步的约束和线性优化计算, 可得到同时满足设计要求和绕组可实现的设计磁场电流分布设计. 计算实例的结果给出了一个提供磁场强度1 .3 Tesla, 长度285 mm 的均匀磁场区域, 同时满足多位置的磁场要求, 设计结果与要求一致度较好, 精度满足应用需求. 该计算方法是一种可适用于较复杂磁场要求和超导绕组结构的设计优化方法.     

Methylthiouracil‐modified Carbon Paste Electrode as a New Voltammetric Sensor Based on a 1,4‐Michael Addition Reaction for Detection of Dopamine

A sensitive dopamine sensor was constructed based on the modified carbon paste electrode with methylthiouracil as a nucleophile in the 1,4‐Michael addition reaction. An ECE mechanism was suggested for dopamine oxidation at the modified electrode. Design of experiments was used in the optimization of variables. Under the optimum conditions, calibration graph was linear in the range of 0.20–15.0 µM with a detection limit of 73 nM. The relative standard deviations (n=5) for 0.50 µM of dopamine was 3.83 %. The selectivity of the sensor was also studied. The developed sensor was applied for analysis of pharmaceutical and biological samples.