Potential of Generalised Two-Dimensional Correlation Spectroscopy in the near Infrared Region
Potential of Generalised Two-Dimensional Correlation Spectroscopy in the near Infrared Region
复制标题
广义二维相关光谱在近红外区域的潜力
DOI：
10.1255/jnirs.79
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发表时间：
1996
影响因子：
1.8
通讯作者：
I. Noda
中科院分区：
文献类型：
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作者：
Y. Ozaki;I. Noda
本文综述了广义二维（2D）相关光谱在近红外（NIR）区域的潜力。本文讨论了广义二维近红外相关分析的三个例子，它们都与自相关分子的温度依赖光谱变化有关。第一个例子用二维相关法分析了温度变化下纯液态油醇的一组近红外光谱。二维近红外分析提高了光谱分辨率，简化了重叠波段的光谱。例如，在7090 cm−1处，由于游离OH基团的旋转异构，单体醇的羟基伸展模式的第一泛音产生的带由两个带组成。第二个例子处理了n -甲基乙酰胺（NMA）随温度变化的近红外光谱变化。在狭窄的光谱和温度窗口下获得的NMA的二维近红外相关光谱的特写视图，使我们不仅提出了6800-6050 cm−1区域的波段分配，其中自由、自由端和氢键NH基团的拉伸模式的第一泛音预计会出现，而且还提出了NMA在每个温度范围内热诱导解离的详细机制图。作为第三个例子，讨论了尼龙12预熔行为和氢键的二维近红外研究。在30 ~ 150℃范围内，在6900 ~ 6100 cm−1范围内，尼龙12的二维非同步近红外相关光谱表明，随着温度的升高，首先出现游离羰基氧酰胺基团，其次是无缔合的游离酰胺基团和含游离NH的酰胺基团。在6000-5500 cm−1区域的非同步光谱中，CH2拉伸模式的第一个泛音预计会出现，这表明在更多有序组分消失之前，大量无序或解离组分开始出现。它们似乎是预熔前体（甚至可能是间接原因），导致与尼龙12在更高温度下熔化有关的有序组分急剧减少。
This review demonstrates the potential of generalised two-dimensional (2D) correlation spectroscopy in the near infrared (NIR) region. Three examples of generalised 2D NIR correlation analysis, which are all concerned with the temperature-dependent spectral variations of self-associated molecules, are discussed in this paper. The first example presents the 2D correlation approach to the analysis of a set of NIR spectra of oleyl alcohol in the pure liquid state under temperature changes. The 2D NIR analysis enhances the spectral resolution and simplifies the spectra with overlapped bands. For example, it was found that a band at 7090 cm−1, arising from the first overtone of an OH stretching mode of the monomeric alcohol, consists of two bands due to the rotational isomerism of the free OH group. The second example deals with the temperature-dependent NIR spectral changes of N-methylacetamide (NMA). The close-up view of 2D NIR correlation spectra of NMA, obtained at narrow spectral and temperature windows, enabled us to propose not only band assignments in the 6800–6050 cm−1 region, where the first overtones of stretching modes of free, free-end and hydrogen-bonded NH groups were expected to appear, but also a detailed mechanistic picture of the thermally-induced dissociation of NMA for each temperature range. A 2D NIR study of premelting behaviour and hydrogen bonds of Nylon 12 is discussed as the third example. The asynchronous 2D NIR correlation spectrum of Nylon 12 obtained from 30 to 150°C in the 6900–6100 cm−1 region indicated that the amide group with a free carbonyl oxygen appears first and then the unassociated free amide and amide with free NH follow as the temperature is increased. The asynchronous spectrum in the 6000–5500 cm−1 region, where the first overtones of the CH2 stretching modes are expected to appear, suggested that a substantial amount of disordered or dissociated components start appearing before the disappearance of more ordered components. It seemed that they appear as the premelting precursors (or even possibly as the indirect cause) to the precipitous decrease of the ordered components associated with the melting of Nylon 12 occurring at a much higher temperature.
Iwahashi 等人：“用 ADP、NADPH 和氯化铁处理的大鼠肝微粒体中 α-(4-吡啶基-1-氧化物)-N-叔丁基硝酮的乙基和戊基加合物的检测” 免费Rad.Res.Comms。
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