関連する実験動画
Updated: Jul 11, 2026

08:44
Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate
Published on: February 23, 2016
タイタン・シリカライト-1のTi調整
Wallace O Parker1, Roberto Millini
1Physical Chemistry Department, EniTecnologie S.p.A., via Maritano 26, 20097 San Donato Milanese, Italy.
Journal of the American Chemical Society
|February 2, 2006
まとめ
シリカライト-1構造にチタン (TiIV) またはボロン (BIII) を組み込むと,シロキシ群が減少する. これは,MFIの枠組みの中でTiO5またはBO4サイトを形成するヘテロ原子の負の電荷を確認します.
科学分野:
- マテリアルサイエンス 材料科学
- カタリシス カタリシス カタリシス
- 無機化学 無機化学とは
背景:
- シリカライト-1 (MFI構造) は,重要なゼオライト材料です.
- ヘテロアトムの組み込みを理解することは,ゼオライトの特性を調整するための鍵です.
- 置換ゼオライトの電荷バランスは,その触媒活性に影響します.
研究 の 目的:
- シリカリート-1に対するTiIVおよびBIIIヘテロアトムの組み込みの影響を調査する.
- ヘテロ原子置換中のシルオキシ群の変化を定量化するために.
- 組み込まれたヘテロ原子の電荷と調整を決定する.
主な方法:
- シリカライト-1の合成,TiIVまたはBIIIの漸進的な同型組み込み.
- 1H マジック・アングル・スピニング・核磁共振 (MAS NMR) スペクトロスコピー.
- シラノール陽子のH結合とシロキシ酸素の定量化.
主要な成果:
- TiIVまたはBIIIの同型組み込みは,シリカライト-1におけるシロキシ群の量を減少させた.
- シロキシ群の減少は,組み込まれたヘテロ原子の量と直接関係しています.
- 1H MAS NMRでは,組み込まれたヘテロ原子の負の電荷が確認されました.
結論:
- 組み込まれたヘテロ原子 (TiIV,BIII) は負の電荷を持つTiO5またはBO4サイトとして存在します.
- この発見は,ヘテロ原子で置換されたシリカライト-1. 1における電荷補償メカニズムを明確にします.
- この研究は,改造されたMFIゼオライトの構造および電子特性についての洞察を提供します.
関連する概念動画
Coordination Compounds and Nomenclature
In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For instance, the four valence electrons of carbon overlap with electrons from four hydrogen atoms to form CH4. The one valence electron leaves sodium and adds to the seven valence electrons of chlorine to form the ionic formula unit NaCl (Figure 1a). Transition metals do not normally bond in this fashion. They primarily form coordinate covalent bonds, a...
Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Coordination Number and Geometry
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
Redox Titration: Other Oxidizing and Reducing Agents
Besides iodine, other oxidizing or reducing agents can serve as titrants in redox titrations. Common oxidizing titrants include KMnO4, cerium(IV), and K2Cr2O7. The choice of oxidizing titrants depends on factors like stability, cost, analyte strength, and reaction rate between the analyte and titrant. KMnO4 is a strong oxidizing titrant that reduces from Mn(VII) to Mn(II) in a highly acidic solution, simultaneously oxidizing the analyte to a higher oxidation state. In this case, KMnO4 acts as a...
EDTA: Auxiliary Complexing Reagents
EDTA titrations are usually carried out in highly basic conditions, where the fully deprotonated form of EDTA, Y4−, actively complexes with the free metal ions in the solution. Several metal ions precipitate as hydrous oxide (hydroxides, oxides, or oxyhydroxides) under these conditions, lowering the concentration of free metal ions in the solution. For this reason, auxiliary complexing agents or ligands such as ammonia, tartrate, citrate, or triethanolamine are used in EDTA titrations to...

