Raman spectrum, conformational stability, barriers to internal rotations and DFT calculations of 1,1,1-trifluoro-propane-2-thione with double-internal-symmetric rotor

Mohamed, Tarek A.; Farag, Rabei S.

doi:10.1016/j.saa.2005.03.007

Cited by 6 publications

(6 citation statements)

References 51 publications

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“…These theoretical values are well correlated to experimental values of 727 ± 3.5 cm À1 (FIR) for propene [71] and 773 cm À1 for isobutene [72], along with 493 ± 21 cm À1 obtained from far IR spectrum of trans,trans-2,4-hexadiene [38]. Hence, the methyl barrier to internal rotation is in good agreement to both theoretical and experimental values [37][38][39][70][71][72]. …”

Section: Ch 3 Barriers To Internal Rotationsupporting

confidence: 85%

“…In both cases there is an imaginary frequency revealing both structures to be transition states. The estimated methyl barriers of 722 and 481 cm À1 for AMPC seem to be consistent with calculated values of 689 cm À1 for trimethyldisilane [37], and average values of 703 cm À1 for trans,trans-2,4-hexadiene [38], 448 cm À1 for 1,1,1-trifluoro-propane-2-thione [39] and 392 cm À1 for 1,1,1-trifluoroacetone [70]. These theoretical values are well correlated to experimental values of 727 ± 3.5 cm À1 (FIR) for propene [71] and 773 cm À1 for isobutene [72], along with 493 ± 21 cm À1 obtained from far IR spectrum of trans,trans-2,4-hexadiene [38].…”

Section: Ch 3 Barriers To Internal Rotationsupporting

confidence: 84%

“…Therefore, a thorough Raman, IR and NMR spectroscopic investigation is reported here complemented by B3LYP theoretical predictions [20][21][22][23][24] with bases sets up to 6-31++G(d,p) to provide novel insight on vibrational assignments and conformational stability of AMPC. Complimentary to our studies on barriers to internal rotations of methyl [37][38][39][40] and NH 2 [41][42][43] rotors, potential surface scans (PSS) of the CH 3 , CH 3 S and NH 2 groups were undertaken to shed light on the rather complicated conformational interchanges in the molecule under investigation.…”

Section: Introductionmentioning

confidence: 99%

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Infrared, Raman and NMR spectra, conformational stability, normal coordinate analysis and B3LYP calculations of 5-amino-4-cyano-3-(methylthio)-1H-pyrazole-1-carbothioamide

Mohamed

Hassan

Soliman

et al. 2011

Journal of Molecular Structure

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Section: Ch 3 Barriers To Internal Rotationsupporting

confidence: 85%

Section: Ch 3 Barriers To Internal Rotationsupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

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Infrared, Raman and NMR spectra, conformational stability, normal coordinate analysis and B3LYP calculations of 5-amino-4-cyano-3-(methylthio)-1H-pyrazole-1-carbothioamide

Mohamed

Hassan

Soliman

et al. 2011

Journal of Molecular Structure

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“…As shown in the figure, three substances contain the same functional groups, which is similar to glucose [17]. In this chart, the bands at 3441cm assigned to C-O-C stretching vibration absorptions [18]. It should be noted that there have been some new characteristic peaks for these three substances.…”

Section: Chemical Characteristics Of Hydrothermal Carbonization Productsmentioning

confidence: 78%

Evolution of Waster Cotton Fiber Hydro-Char Physicochemical Structure during Hydrothermal Carbonation

Shi¹,

Zhang²,

Zhang³

et al. 2017

Preprint

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Abstract：In order to study the hydrothermal behavior of cotton fiber, the carbonization process and structural evolution of discarded cotton fiber (WCF) under hydrothermal conditions were discussed use microcrystalline cellulose (MCC) and glucose as model compounds. The results showed that high temperature was beneficial to the hydrolysis of discarded cotton fiber, and the yield of the sugar was 4.5% which was lower than that of MCC 6.51%.WFC and MCC are carbonized in 240~260 ℃ and 220~240 ℃ respectively, while the carbonation temperature of glucose is lower than 220 ℃. The quality ratio of C/O in WCF and glucose hydrothermal products is 5.79 and 5.85 respectively; three kinds of hydrothermal carbonization products have similar crystal structure and oxygen-containing functional groups, and the WCF carbonization products contain a lot of irregular particles while the main products of glucose carbonization are 0.5 μm carbon microspheres (CMCC). The results show that glucose is an important intermediate product of WCF hydrolysis carbonation, and there are two main paths of cotton fiber hydrothermal carbonization: some cotton fibers are completely hydrolyzed into glucose and the nucleation is formed, and then the carbon microspheres are grown; for the other part, the glucose ring of the polysaccharide oligosaccharide formed by the incomplete hydrolysis of cotton fiber in the hydrothermal environment of high temperature and pressure breaks, then forms the particulate matters.

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“…Peaks at 3,441 and 1,023 cm -1 were assigned to -OH stretching vibrations, whereas peak at 2,923 cm -1 was attributed to C-H stretching vibrations. Peaks at 1,299 and 1,208 cm -1 could be assigned to C-O-C stretching vibrations [17]. The three samples showed some new characteristic peaks.…”

Section: Chemical Nature Of Hydrothermal Carbonization Productsmentioning

confidence: 87%

Evolution of Physicochemical Structure of Waste Cotton Fiber (Hydrochar) During Hydrothermal Carbonation

Shi

Zhang

et al. 2020

Autex Research Journal

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To study the hydrothermal behavior of cotton fiber, the carbonization process and structural evolution of discarded or waste cotton fiber (WCF) under hydrothermal conditions were investigated using microcrystalline cellulose (MCC), and glucose was used as a model compound. Results showed that high temperature was beneficial for the hydrolysis of discarded cotton fiber, and the yield of sugar was 4.5%, which was lower than that of MCC (6.51%). WCF and MCC were carbonized at 240–~260°C and 220–~240°C, respectively, whereas the carbonization temperature of glucose was lower than 220°C. The C/O ratios of WCF and glucose hydrothermal products were 5.79 and 5.85, respectively. The three kinds of hydrothermal carbonization products had similar crystal structures and oxygen-containing functional groups. The carbonized products of WCF contained many irregular particles, while the main products of glucose carbonization were 0.5-mm-sized carbon microspheres (CMSs). Results showed that glucose was an important intermediate in WCF carbonization and that there were two main pathways of hydrothermal carbonization of cotton fibers: some cotton fibers were completely hydrolyzed into glucose accompanied by nucleation and then the growth of CMSs. For the other part, the glucose ring of the oligosaccharide, formed by the incomplete hydrolysis of cotton fibers under hydrothermal conditions of high temperature and pressure, breaks and then forms particulate matter.

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Raman spectrum, conformational stability, barriers to internal rotations and DFT calculations of 1,1,1-trifluoro-propane-2-thione with double-internal-symmetric rotor

Cited by 6 publications

References 51 publications

Infrared, Raman and NMR spectra, conformational stability, normal coordinate analysis and B3LYP calculations of 5-amino-4-cyano-3-(methylthio)-1H-pyrazole-1-carbothioamide

Infrared, Raman and NMR spectra, conformational stability, normal coordinate analysis and B3LYP calculations of 5-amino-4-cyano-3-(methylthio)-1H-pyrazole-1-carbothioamide

Evolution of Waster Cotton Fiber Hydro-Char Physicochemical Structure during Hydrothermal Carbonation

Evolution of Physicochemical Structure of Waste Cotton Fiber (Hydrochar) During Hydrothermal Carbonation

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