ニトリル赤外線強度は,プロティック,アプロティック,およびタンパク質環境における電気場と水素結合を特徴づけている
Jared Bryce Weaver1, Jacek Kozuch2, Jacob M Kirsh1
1Department of Chemistry, Stanford University, Stanford, California 94305-5012, United States.
Journal of the American Chemical Society
|April 25, 2022
まとめ
この研究は,ナトリルの新しい振動性スターク効果 (VSE) を導入し,水素結合を含む様々な環境で正確な電気場測定を可能にします. この方法は,より広範なアプリケーションのためのニトリル振動スペクトロスコーピーを強化します.
科学分野:
- 生物物理化学
- スペクトロスコーピー
- タンパク質工学
背景:
- ニトリルは貴重な振動探知器ですが,プロティック環境での水素結合 (H結合) により,赤外線 (IR) 周波数解釈は困難です.
- 生物学的システム内の電場を理解することは 分子機構の解読に不可欠です
研究 の 目的:
- ニトリルを使って電場を定量化するための新しい振動型スターク効果 (VSE) 方法を開発する.
- H結合と非H結合の相互作用の両方に適用される一般的なアプローチを確立する.
- ニトリル周波数シフトに対するH結合の貢献の半経験的決定を可能にする.
主な方法:
- ニトリル結合 (-CN) の電場と移行二極 Moment とピーク エリアを相関させる線形 VSE を開発した.
- 珀の抑制を用いてタンパク質に ニトリル変種を組み込みました
- 高解像度構造分析を用いてニトリルを含むタンパク質を特徴づけた.
主要な成果:
- H結合環境と非H結合環境の両方に適用可能な線形VSEが実証されました.
- 組み合わせた頻度と統合された強度分析の有用性を示しました.
- 多様な環境で電場を測定するための多用途の探査機として,検証されたニトリル.
結論:
- 新しいVSEは,複雑な環境で電場を決定するための堅固な方法を提供します.
- このVSEで分析されたナトリルは,局所的な電場を検知するための一般的に適用可能なツールを提供します.
- この技術は,生体物理学的および化学的研究における振動スペクトロスコピーの使用を進める.
さらに関連する動画
関連する概念動画
IR Frequency Region: X–H Stretching
1.1K
In IR spectroscopy, signals produced by the X−H bonds (such as C−H, O−H, or N−H) can be observed in the frequency range of 2700–4000 cm–1. The C−H stretching vibration forms sharp bands in the region 2850–3000 cm–1. The presence of the O−H stretching vibration leads to the forming of an absorption band in the frequency range 3650–3200 cm−1. At the same time, N−H stretching can be confirmed by absorption bands in...
1.1K
NMR Spectroscopy Of Amines
9.5K
In proton NMR spectroscopy, primary amines and secondary amines showcase their N–H protons as a broad signal in the chemical shift range between δ 0.5 and 5 ppm. The exact position in this range depends on several factors, including sample concentration, hydrogen bonding, and the type of solvent used. Since amine protons undergo fast proton exchange in solution, the protons are labile and therefore do not participate in any splitting with adjacent protons. Thus, the observed peak is...
9.5K
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
1.2K
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
1.2K
IR Frequency Region: Alkyne and Nitrile Stretching
1.0K
Both alkyne (C≡C) and nitrile (C≡N) functional groups contain triple bonds and show stretching absorptions around the wavenumber range of 2100 to 2300 cm−1 in the diagnostic region of the IR spectra.
Comparing the stretching vibrational frequency of C≡C triple bonds with that of double and single bonds, it is evident that C≡C triple bonds exhibit a higher stretching frequency than C=C double and C–C single bonds. Similarly, the C≡N triple bond...
Comparing the stretching vibrational frequency of C≡C triple bonds with that of double and single bonds, it is evident that C≡C triple bonds exhibit a higher stretching frequency than C=C double and C–C single bonds. Similarly, the C≡N triple bond...
1.0K
IR Spectrum Peak Broadening: Hydrogen Bonding
1.2K
The vibrational frequency of a bond is directly proportional to its bond strength. As a result, stronger bonds vibrate at higher frequencies, while weaker bonds vibrate at lower frequencies. The stretching vibration of the strong O–H bond in alcohols and phenols (very dilute solution or gas phase) appears as a sharp peak at 3600–3650 cm−1.
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular...
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular...
1.2K
Proton (¹H) NMR: Chemical Shift
2.0K
Organic molecules primarily contain carbon and hydrogen atoms. While all the hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant. It has a significant energy separation between its nuclear spin states due to its large gyromagnetic ratio. As per Boltzmann's distribution, an increase in the energy separation implies a greater excess population of nuclei available for excitation, resulting in a strong NMR absorption signal.
Absorption signals of all the protium nuclei...
Absorption signals of all the protium nuclei...
2.0K
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)

