{"title":"合成无水醋酸镧。分析其结构、热和电子特性","authors":"","doi":"10.1016/j.ica.2024.122310","DOIUrl":null,"url":null,"abstract":"<div><p>Acetate complexes of rare earth elements are extensively studied compounds known for their diverse properties and potential applications and lanthanum acetate hydrate is commercially available. In this work, a powdered anhydrous lanthanum acetate (La(CH<sub>3</sub>COO)<sub>3</sub>) sample was prepared by dissolving lanthanum oxide (La<sub>2</sub>O<sub>3</sub>) in an excess of acetic acid (CH<sub>3</sub>COOH) and distilled water (H<sub>2</sub>O), followed by direct evaporation at 150 °C. The decomposition of La(CH<sub>3</sub>COO)<sub>3</sub> was studied, showing initiation around 300 °C and conclusion at ≥700 °C, with four distinct thermal events (I–IV) of mass loss. Gas phase identification revealed acetone and carbon dioxide as decomposition products, indicating pyrolytic decarboxylation. The final thermal effect (IV) is linked to the decomposition of La<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> to La<sub>2</sub>O<sub>3</sub>. The DFT refinement of atomic coordinates of hydrogen atoms, which were unavailable from experiment, was successfully performed. Obtained structural data was checked using vibrational spectroscopy method. The calculated electronic band structure of La(CH<sub>3</sub>COO)<sub>3</sub> indicates it as an indirect wide band gap material with values of direct transition close to indirect. The optical bandgap is found to be 5.49 eV, suggesting that the charge transfer in La(CH<sub>3</sub>COO)<sub>3</sub> can be optically activated with wavelengths shorter than 226 nm, which falls within the deep UV (DUV) region.</p></div>","PeriodicalId":13599,"journal":{"name":"Inorganica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Synthesis of anhydrous lanthanum acetate. Analysis of it’s structural, thermal and electronic properties\",\"authors\":\"\",\"doi\":\"10.1016/j.ica.2024.122310\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Acetate complexes of rare earth elements are extensively studied compounds known for their diverse properties and potential applications and lanthanum acetate hydrate is commercially available. In this work, a powdered anhydrous lanthanum acetate (La(CH<sub>3</sub>COO)<sub>3</sub>) sample was prepared by dissolving lanthanum oxide (La<sub>2</sub>O<sub>3</sub>) in an excess of acetic acid (CH<sub>3</sub>COOH) and distilled water (H<sub>2</sub>O), followed by direct evaporation at 150 °C. The decomposition of La(CH<sub>3</sub>COO)<sub>3</sub> was studied, showing initiation around 300 °C and conclusion at ≥700 °C, with four distinct thermal events (I–IV) of mass loss. Gas phase identification revealed acetone and carbon dioxide as decomposition products, indicating pyrolytic decarboxylation. The final thermal effect (IV) is linked to the decomposition of La<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> to La<sub>2</sub>O<sub>3</sub>. The DFT refinement of atomic coordinates of hydrogen atoms, which were unavailable from experiment, was successfully performed. Obtained structural data was checked using vibrational spectroscopy method. The calculated electronic band structure of La(CH<sub>3</sub>COO)<sub>3</sub> indicates it as an indirect wide band gap material with values of direct transition close to indirect. The optical bandgap is found to be 5.49 eV, suggesting that the charge transfer in La(CH<sub>3</sub>COO)<sub>3</sub> can be optically activated with wavelengths shorter than 226 nm, which falls within the deep UV (DUV) region.</p></div>\",\"PeriodicalId\":13599,\"journal\":{\"name\":\"Inorganica Chimica Acta\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.7000,\"publicationDate\":\"2024-08-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Inorganica Chimica Acta\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0020169324004018\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inorganica Chimica Acta","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0020169324004018","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
摘要
稀土元素的醋酸盐络合物因其多种多样的特性和潜在应用而被广泛研究,醋酸镧水合物可在市场上买到。在这项工作中,通过将氧化镧(La2O3)溶解在过量的醋酸(CH3COOH)和蒸馏水(H2O)中,然后在 150 °C 下直接蒸发,制备出了粉末状无水醋酸镧(La(CH3COO)3)样品。研究表明,La(CH3COO)3 的分解过程在 300 °C 左右开始,在 ≥700 °C 时结束,有四个不同的质量损失热事件(I-IV)。气相鉴定显示分解产物为丙酮和二氧化碳,表明发生了热解脱羧反应。最后的热效应(IV)与 La2O2CO3 分解为 La2O3 有关。实验中无法获得的氢原子的原子坐标已成功地进行了 DFT 精炼。利用振动光谱法对所获得的结构数据进行了检验。计算得出的 La(CH3COO)3 电子能带结构表明,它是一种间接宽带隙材料,直接转变值接近间接值。光带隙为 5.49 eV,这表明 La(CH3COO)3 中的电荷转移可以在波长短于 226 nm(属于深紫外(DUV)区域)的条件下被光学激活。
Synthesis of anhydrous lanthanum acetate. Analysis of it’s structural, thermal and electronic properties
Acetate complexes of rare earth elements are extensively studied compounds known for their diverse properties and potential applications and lanthanum acetate hydrate is commercially available. In this work, a powdered anhydrous lanthanum acetate (La(CH3COO)3) sample was prepared by dissolving lanthanum oxide (La2O3) in an excess of acetic acid (CH3COOH) and distilled water (H2O), followed by direct evaporation at 150 °C. The decomposition of La(CH3COO)3 was studied, showing initiation around 300 °C and conclusion at ≥700 °C, with four distinct thermal events (I–IV) of mass loss. Gas phase identification revealed acetone and carbon dioxide as decomposition products, indicating pyrolytic decarboxylation. The final thermal effect (IV) is linked to the decomposition of La2O2CO3 to La2O3. The DFT refinement of atomic coordinates of hydrogen atoms, which were unavailable from experiment, was successfully performed. Obtained structural data was checked using vibrational spectroscopy method. The calculated electronic band structure of La(CH3COO)3 indicates it as an indirect wide band gap material with values of direct transition close to indirect. The optical bandgap is found to be 5.49 eV, suggesting that the charge transfer in La(CH3COO)3 can be optically activated with wavelengths shorter than 226 nm, which falls within the deep UV (DUV) region.
期刊介绍:
Inorganica Chimica Acta is an established international forum for all aspects of advanced Inorganic Chemistry. Original papers of high scientific level and interest are published in the form of Articles and Reviews.
Topics covered include:
• chemistry of the main group elements and the d- and f-block metals, including the synthesis, characterization and reactivity of coordination, organometallic, biomimetic, supramolecular coordination compounds, including associated computational studies;
• synthesis, physico-chemical properties, applications of molecule-based nano-scaled clusters and nanomaterials designed using the principles of coordination chemistry, as well as coordination polymers (CPs), metal-organic frameworks (MOFs), metal-organic polyhedra (MPOs);
• reaction mechanisms and physico-chemical investigations computational studies of metalloenzymes and their models;
• applications of inorganic compounds, metallodrugs and molecule-based materials.
Papers composed primarily of structural reports will typically not be considered for publication.