Quantum chemistry studies of far-infrared spectra of aromatic urethanes

Maklakov, L. I.; Сучкова, Г. Г.

doi:10.1016/j.saa.2007.12.009

Cited by 4 publications

(4 citation statements)

References 11 publications

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“…From Figure 1 (c-e) and Figure 1 (h-k) [6][7][8][11][12][13], the degree of order of hydrogen bonding increases. It is very important to note that urethane and urea groups are planar [24][25][26]. When hydrogen bonds between urethane or urea groups are formed, the system of hydrogen bonds is a planar or zig-zag and spiral conformation [7,24].…”

Section: Distinctions Of Infrared Peak Positions Of Hydrogen Bonded U...mentioning

confidence: 99%

“…On the one hand, when ether linkage associates with NH to form hydrogen bonding, shown in Figure 1 (g), (l), (m), (n) and (o) [6][7][8][11][12][13] respectively, the vibration of hydrogen bonded NH compared with free urethane NH or urea NH is subject to certain restrictions. Because urethane or urea groups are planar [24][25][26], the vibration of C=O is also subject to certain restrictions, leading to slight shifts to lower frequencies. On the other hand, when ether linkage associates with NH to form hydrogen bonding, the steric hindrance of C=O increases, resulting in slight shifts to lower frequencies.…”

Section: Distinctions Of Infrared Peak Positions Of Hydrogen Bonded U...mentioning

confidence: 99%

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Hydrogen Bonds and FTIR Peaks of Polyether Polyurethane-Urea

Zhao

et al. 2019

KEM

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Various types of hydrogen bonds exist in polyether polyurethane, polyurethane-urea and polyurea (PUA) and can cause microphase separation. The morphology, properties and applications of polyether PUA are determined by the microphase separation. All kinds of hydrogen bonds make it difficult to assignments of Fourier transform infrared spectroscopy (FTIR) peaks of ether linkage, amine and carbonyl group. This affects the calculation of the hydrogen bonding degree of the hard segments for estimating the degree of microphase separation. This paper summarized hydrogen bonding structures between proton donors and proton acceptors. By analyzing the influence of electronic effect, steric effect, various types of hydrogen bonds and the degree of order of hydrogen bonding on infrared peaks, the relationships between hydrogen bonding structures and infrared peaks are established. Lay the theoretical foundation for evaluating the degree of microphase separation by FTIR method.

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Section: Distinctions Of Infrared Peak Positions Of Hydrogen Bonded U...mentioning

confidence: 99%

Section: Distinctions Of Infrared Peak Positions Of Hydrogen Bonded U...mentioning

confidence: 99%

Hydrogen Bonds and FTIR Peaks of Polyether Polyurethane-Urea

Zhao

et al. 2019

KEM

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“…As shown in Figure a, the peaks at 1667, 1545 cm –1 are attributed to the CO stretching vibration of benzaldehyde, − while the peak at 1436 cm –1 is attributed to the OH out-of-plane bending vibration of benzoic acid. , The red-shifted peak at 1384 cm –1 may be attributed to the tensile strain within the benzene ring, suggesting a potential occurrence of benzene ring cleavage at this specific location . Furthermore, the presence of the CO stretching vibration peak of CO 2 corresponding to 2376 and 2319 cm –1 indicates that toluene is ultimately mineralized into CO 2 .…”

Section: Resultsmentioning

confidence: 97%

“…41,42 The redshifted peak at 1384 cm −1 may be attributed to the tensile strain within the benzene ring, suggesting a potential occurrence of benzene ring cleavage at this specific location. 45 Furthermore, the presence of the C�O stretching vibration peak of CO 2 corresponding to 2376 and 2319 cm −1 indicates that toluene is ultimately mineralized into CO 2 . 31 A similar peak can be detected for TiO 2 -110 (Figure 4b and Tables S3 and S4).…”

Section: ■ Introductionmentioning

confidence: 99%

Facet-Dependent Photocatalytic Behavior of Rutile TiO₂ for the Degradation of Volatile Organic Compounds: In Situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy and Density Functional Theory Investigations

Zhou,

Chen,

et al. 2024

Langmuir

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In this study, a custom rutile titanium dioxide (TiO 2 ) photocatalyst with a single exposed surface was utilized to investigate the facet-dependent photocatalytic mechanism of toluene. The degradation of toluene was dynamically monitored using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) technology coupled with theoretical calculations. The findings demonstrated that the photocatalytic degradation rate on the TiO 2 (001) surface was nearly double that observed on the TiO 2 (110) surface. This remarkable enhancement can be attributed to the heightened stability in the adsorption of toluene molecules and the concurrent reduction in the energy requirement for the ring-opening process of benzoic acid on the TiO 2 (001) surface. Moreover, the TiO 2 (001) surface generated a greater number of reactive oxygen species (ROS), thereby promoting the separation of photogenerated charge carriers and concurrently diminishing their recombination rates, amplifying the efficiency of photocatalysis. This research provides an innovative perspective for a more comprehensive understanding of the photocatalytic degradation mechanism of TiO 2 and presents promising prospects for significant applications in environmental purification and energy fields.

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