Heptagon-Containing Nanographene Embedded into [10]Cycloparaphenylene

We report the synthesis and characterization of a novel type of nanohoop, consisting of a cycloparaphenylene derivative incorporating a curved heptagon-containing π-extended polycyclic aromatic hydrocarbon (PAH) unit. We demonstrate that this new macrocycle behaves as a supramolecular receptor of curved π-systems such as fullerenes C₆₀ and C₇₀, with remarkably large binding constants (ca. 10⁷ M⁻¹), as estimated by fluorescence measurements. Nanosecond and femtosecond spectroscopic analysis show that these host-guest complexes are capable of quasi-instantaneous charge separation upon photoexcitation, due to the ultrafast charge transfer from the macrocycle to the complexed fullerene. These results demonstrate saddle-shaped PAHs with dibenzocycloheptatrienone motifs as structural components for new macrocycles displaying molecular receptor abilities and versatile photochemical responses with promising electron-donor properties in host-guest complexes.     

Self-Assembled Monolayers of Bi-Functionalized Porphyrins: A Novel Class of Hole-Layer-Coordinating Perovskites and Indium Tin Oxide in Inverted Solar Cells

Self-assembled monolayers (SAMs) offer the advantage of facile interfacial modification, leading to significant improvements in device performance. In this study, we report the design and synthesis of a new series of carboxylic acid-functionalized porphyrin derivatives, namely AC-1, AC-3, and AC-5, and present, for the first time, a strategy to exploit the large π-moiety of porphyrins as a backbone for interfacing the indium tin oxide (ITO) electrode and perovskite active layer in an inverted perovskite solar cell (PSC) configuration. The electron-rich nature of porphyrins facilitates hole transfer and the formation of SAMs, resulting in a dense surface that minimizes defects. Comprehensive spectroscopic and dynamic studies demonstrate that the double-anchored AC-3 and AC-5 enhance SAMs on ITO, passivate the perovskite layer, and function as conduits to facilitate hole transfer, thus significantly boosting the performance of PSCs. The champion inverted PSC employing AC-5 SAM achieves an impressive solar efficiency of 23.19 % with a high fill factor of 84.05 %. This work presents a novel molecular engineering strategy for functionalizing SAMs to tune the energy levels, molecular dipoles, packing orientations to achieve stable and efficient solar performance. Importantly, our comprehensive investigation has unraveled the associated mechanisms, offering valuable insights for future advancements in PSCs.     

便携式X射线荧光光谱仪在污染场地中重金属检测的应用

为探究便携式X射线荧光光谱法(Portable X-ray fluorescence spectrometry method, PXRF)测定结果的不确定度, 应用PXRF法和传统实验室方法对湖南某典型有色金属污染场地及周边土壤中的重金属进行测定,通过建立线性回归模型对比分析两种方法的测定数据,探究了PXRF法测定数据的准确程度和置信区间。结果表明,PXRF法原位、异位测定值与传统实验室方法测定值均能呈现较好的线性相关性,As、Cu、Pb、Cd等元素的决定性系数(R2)均大于0.70,其检测数据质量均能达到定量水平;PXRF法与实验室方法测定值间比率的置信区间结果显示,Cd元素的准确性最好,其次为Pb、Cu、As,比率置信区间分别为(0.57, 1.89)、(0.38, 2.22)、(0.31, 2.25)、(0.20, 4.53)。由此可见,PXRF法是一种方便快捷且相对准确的土壤重金属现场检测方法,可广泛地应用于污染场地调查和土壤修复工程实践中。     

Highly Conjugated Bis(benzo[b]phosphole)-P-oxides: Synthesis and Electrochemical,Optical, and Computational Studies

The first examples of a π-conjugated benzo[b]phosphole P-oxide in which two phosphole P-oxide units are connected by a carbon-carbon double bond are described. The molecules are synthesized as E isomers with respect to the carbon-carbon double bond and exist as stable cis and trans isomers (chiral and meso one respectively) relatively to the two stereogenic P atoms. The optical and electrochemical properties of both isomers have been investigated by experiment and computations.     

Cover Picture: Nanomaterials for Fluorescence and Multimodal Bioimaging (Chem. Rec. 3/2023)

Bioconjugated nanomaterials replace molecular probes in bioanalysis and bioimaging in vitro and in vivo. Nanoparticles of silica, metals, semiconductors, polymers, and supramolecular systems, conjugated with contrast agents and drugs for image-guided (MRI, fluorescence, PET, Raman, SPECT, photodynamic, photothermal, and photoacoustic) therapy infiltrate into preclinical and clinical settings. Small bioactive molecules like peptides, proteins, or DNA conjugated to the surfaces of drugs or probes help us to interface them with cells and tissues. Nevertheless, the toxicity and pharmacokinetics of nanodrugs, nanoprobes, and their components become the clinical barriers, underscoring the significance of developing biocompatible next-generation drugs and contrast agents. This account provides state-of-the-art advancements in the preparation and biological applications of bioconjugated nanomaterials and their molecular, cell, and in vivo applications. It focuses on the preparation, bioimaging, and bioanalytical applications of monomodal and multimodal nanoprobes composed of quantum dots, quantum clusters, iron oxide nanoparticles, and a few rare earth metal ion complexes.     

Synthesis of polyaspartic acid-glycidyl adduct and evaluation of its scale inhibition performance and corrosion inhibition capacity for Q235 steel applications

In this work, the development of the eco-friendly comprehensive scale and corrosion inhibitor based on green polyaspartic acid (PASP) was presented. In this view, PASPG was prepared by a ring-opening graft modification reaction of polysuccinimide (PSI) with glycidyl. In addition, the molecular structure and the thermal stability of PASPG were characterized by using three different methods (FTIR, ¹H NMR, and TGA). PASPG’s scale inhibition efficiency and corrosion inhibition efficiency were also evaluated, respectively. More concretely, the scale inhibition efficiency of PASPG achieved 94.6 % and 95.1 % for CaCO₃ and CaSO₄, respectively. With the aid of the FTIR and SEM measurement techniques, it was found that PASPG could induce the irregular growth of the CaCO₃ and CaSO₄ morphology and destroy the formation of crystals. On the other hand, the higher corrosion efficiency of 85.17 % was achieved by PASPG in comparison with PASP (72.53 %). PASPG is a mixed inhibitor and the adsorption of PASPG on the Q235 steel surface followed the Langmuir mono-layer adsorption isotherm. The formation of a protective film on the surface of carbon steel was proved by PASPG’s adsorption, which increased the resistance to be eroded. Thus, the surface of carbon steel can be effectively protected. The present work provides a simple and effective pathway for the synthesis of high-efficiency green scale and corrosion inhibitor, by introducing a functional group into the PASP chains. The implementation of such type of chemical modification method may also be an effective strategy for improving the efficiency of other polymers green scale and corrosion inhibitors.     

基于LSTM的浮选钼精矿品位软测量模型

战略性稀有金属钼矿品位低,组分复杂、嵌布粒度细等特点,其有价金属分离回收难。浮选作为微细粒钼矿分离回收的主要选矿方法之一,其浮选钼精矿品位一直是选厂的关键性产品指标。国内大多数选厂采取轮班制采样,人工化验得到精矿品位结果,但此方式严重滞后于浮选工艺,难以满足对生产过程进行实时监测和操作指导。LSTM是一种特殊的循环神经网络,引入门机制有效的传递或选择性遗忘长时间序列中的信息,解决RNN中的长期依赖、梯度消失和爆炸问题。本文分析整理东坡选厂中各平台源数据,结合选厂浮选工艺及机理,筛选出多个影响浮选钼精矿品位的变量作为模型输入;将输入变量进行异常值判定,缺失值填充和数据降噪等数据预处理,建立高质量浮选钼精矿品位数据库;软测量模型采用PyCharm软件编码,使用BatchNorm批量规范化处理样本数据,加入Dropout正则化防止过拟合,建立基于LSTM的浮选钼精矿品位软测量模型,通过前向传播算法更新神经网络结构参数,并于Linear模型和CNN模型的预测性能指标结果比较。结果表明：基于LSTM的浮选钼精矿品位软测量模型预测准确度高,样本数据误差波动平稳,浮动范围小,模型泛化能力强,模型平均绝对百分比误差MAPE为1.13%,均方根误差RMSE为0.7049%,决定系数R2为0.8763,实现了浮选钼精矿品位的在线预测。     

硫酸镉无机层和原位反应生成的吡啶基四氮唑有机配体构筑的两个层-柱状三维无机-有机杂化材料:合成和表征

以硫酸镉、叠氮化钠和4-氰基吡啶或3-氰基吡啶为反应物,在水热条件下,通过原位反应分别得到了2个基于硫酸根离子和5-(4-吡啶基)四氮唑(4-Hptz)或5-(3-吡啶基)四氮唑(3-Hptz)配体的,具有三维层-柱状框架结构的无机-有机杂化材料,即[Cd₂(H₂O)(OH)(SO₄)(4-ptz)]_n(1)和[Cd₂(OH)(SO₄)(3-ptz)]_n(2)。通过元素分析、红外光谱、热重分析以及单晶和粉末X-射线衍射分析对它们的组成和结构进行了表征。在配合物1和2的结构中,每个镉(Ⅱ)离子的配位数均为6,处于扭曲的八面体配位环境中,SO₄^2-和OH-阴离子连接镉(Ⅱ)离子扩展形成碱式硫酸镉的二维无机阳离子层结构[Cd₂(H₂O)(OH)(SO₄)]_nⁿ⁺(1)或[Cd₂(OH)(SO₄)]_nⁿ⁺(2),相邻的二维无机阳离子层间再通过4-ptz^-(1)或3-ptz^-(2)进一步柱连接,形成三维层-柱状结构的无机-有机杂化框架结构。室温下的固体荧光实验表明,在350nm的光激发下,配合物1和2分别在481和489nm处出现强烈的荧光发射。     

X射线荧光光谱法在标准中的应用

综述了国内外采用X射线荧光光谱法的各类标准,其中包括美国材料与试验协会(ASTM)标准、国际标准化组织(ISO)标准和我国国家标准,主要应用在石油及产品、合金和矿石中元素的含量测定(引用文献31篇)。     

紫外荧光光谱法测定焦炉气中的痕量总硫

采用紫外荧光光谱法测定焦炉气制取液化天然气的原料气中痕量总硫,考察了样品引入速率、进样量、气体流量、燃烧温度、取样方式和进样方式等条件对分析结果的影响。总硫检出限为15μL·m-3,测定结果与气相色谱法和微库仑法的结果相吻合,测定值的相对标准偏差(n=7)小于10%。