Mohammadi Ziarani Ghodsi, Rezakhani Mahtab, Feizi-Dehnayebi Mehran, Nikolova Stoyanka
Department of Organic Chemistry, Faculty of Chemistry, Alzahra University, P.O. Box 19938-93973 Tehran, Iran.
Department of Organic Chemistry, Faculty of Chemistry, University of Plovdiv Paisii Hilendarski, 4000 Plovdiv, Bulgaria.
Molecules. 2024 Oct 11;29(20):4825. doi: 10.3390/molecules29204825.
The surface of fumed silica nanoparticles was modified by pyridine carbaldehyde and barbituric acid to provide fumed-Si-Pr-Ald-Barb. The structure was identified and investigated through diverse techniques, such as FT-IR, EDX, Mapping, BET, XRD, SEM, and TGA. This nanocomposite was used to detect different cations and anions in a mixture of HO:EtOH. The results showed that fumed-Si-Pr-Ald-Barb can selectively detect Hg and CrO ions. The detection limits were calculated at about 5.4 × 10 M for Hg and 3.3 × 10 M for CrO ions. A computational method (DFT) was applied to determine the active sites on the Pr-Ald-Barb for electrophilic and nucleophilic attacks. The HOMO-LUMO molecular orbital was calculated by B3LYP/6-311G(d,p)/LANL2DZ theoretical methods. The energy gap for the Pr-Ald-Barb and Pr-Ald-Barb+ion complexes was predicted by the E and E values. The DFT calculation confirms the suggested experimental mechanism for interacting the Pr-Ald-Barb with ions.
用吡啶甲醛和巴比妥酸对气相二氧化硅纳米颗粒的表面进行改性，得到气相二氧化硅-吡啶甲醛-巴比妥酸（fumed-Si-Pr-Ald-Barb）。通过傅里叶变换红外光谱（FT-IR）、能量散射X射线光谱（EDX）、元素分布图、比表面积分析仪（BET）、X射线衍射仪（XRD）、扫描电子显微镜（SEM）和热重分析仪（TGA）等多种技术对其结构进行了鉴定和研究。该纳米复合材料用于检测水与乙醇混合溶液中的不同阳离子和阴离子。结果表明，气相二氧化硅-吡啶甲醛-巴比妥酸能够选择性地检测汞离子和铬酸根离子。汞离子的检测限计算得出约为5.4×10⁻⁶ M，铬酸根离子的检测限为3.3×10⁻⁶ M。采用一种计算方法（密度泛函理论，DFT）来确定吡啶甲醛-巴比妥酸上亲电和亲核攻击的活性位点。通过B3LYP/6-311G(d,p)/LANL2DZ理论方法计算了最高占据分子轨道（HOMO）-最低未占据分子轨道（LUMO）。通过E和E值预测了吡啶甲醛-巴比妥酸和吡啶甲醛-巴比妥酸+离子配合物的能隙。DFT计算证实了所提出的吡啶甲醛-巴比妥酸与离子相互作用的实验机理。
