タイタナサイクロブタン複合体の (C-C) ->Tiアゴスティック相互作用の電荷密度分析
Stephan Scheins1, Marc Messerschmidt, Milan Gembicky
1Department of Chemistry, University of New York at Buffalo, Buffalo, New York 14260, USA.
Journal of the American Chemical Society
|April 16, 2009
まとめ
この研究は,実験的な電子密度を用いたチタン複合体におけるアゴスティック相互作用の直接的な証拠を提供します. これらの相互作用は,チタン原子近くの炭素-炭素結合のユニークな歪みを引き起こします.
科学分野:
- 有機金属化学 有機金属化学
- 固体化学 固体化学
- コンピューティング・ケミストリー
背景:
- アゴスティック相互作用は,有機金属化学における重要な非共性相互作用である.
- これらの相互作用を理解すると,結合と反応性についての洞察が得られます.
- タイタンの複合体は,ユニークな結合現象を研究するためのプラットフォームを提供します.
研究 の 目的:
- タイタン複合体におけるアゴスティック相互作用の直接的な実験的証拠を提供すること.
- アゴスティック相互作用の電子的および構造的影響を調査する.
- アゴスティック相互作用の理論モデルを検証する.
主な方法:
- 実験的な電子密度研究で,X線微分法を用いた.
- B3LYP関数を持つ密度関数理論 (DFT) を採用した理論的計算.
- 結合密度と原子軌道集団の分析.
主要な成果:
- Ti-C-C) アゴスティック相互作用の直接的な実験的証拠が観察されました.
- C (α) - C (β) 結合密度は,Ti原子近くの円筒対称性からの偏差を示した.
- 理論的な計算は,実験結果とシェラー-マクグレイディ基準を裏付けました.
- Ti (IV) 種では,非ゼロのd軌道集団,特にd (xy) が発見され,アゴスティック相互作用と相関していた.
結論:
- アゴスティック相互作用は,チタン複合体における電子密度分布を著しく影響する.
- 実験的および理論的方法により,これらの相互作用を効果的に特徴付けることができます.
- この研究は,有機金属チタン化合物の結合のより深い理解に貢献します.
さらに関連する動画
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
11:38Quantifying the Binding Interactions Between Cu(II) and Peptide Residues in the Presence and Absence of Chromophores
Published on: April 5, 2022
関連する概念動画
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:42Valence 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...
01:18Aromatic Hydrocarbon Cations: Structural Overview
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
Removing one hydrogen from the intervening CH2 group with both...
03:45Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
00:43Complexometric Titration: Ligands
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...