Raman, infrared and NMR spectral analysis, normal coordinate analysis and theoretical calculations of 5-(methylthio)-1,3,4-thiadiazole-2(3H)-thione and its thiol tautomer

Mohamed, Tarek A.; Soliman, Usama A.; Shaaban, Ibrahim A.; Zoghaib, Wajdi M.; Wilson, Lee D.

doi:10.1016/j.saa.2015.05.039

Cited by 17 publications

(8 citation statements)

References 55 publications

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“…The intermolecular H‐bonding leads to a shift in NH stretch ( ν 1 ) as low as 3100 cm −1 , [ 51 ] which was found to be consistent with the observed IR/Raman bands at 3121 (m)/3120 (w) nearby that computed at 3122 cm −1 for H‐bonded dimer and that was found in agreement with Mohamed et al [ 52 ] and X‐rays. [ 20 ] The δ ip NH of the dimer is observed/scaled at 1465 (m)/1455 cm −1 ( ν 9 ) accompanied by a shoulder at 1484 (w)/1488 cm −1 ( ν 18 ).…”

Section: Resultssupporting

confidence: 88%

“…(m)/3120 (w) nearby that computed at 3122 cm À1 for Hbonded dimer and that was found in agreement with Mohamed et al [52] and X-rays. [20] The δ ip N H of the dimer is observed/scaled at 1465 (m)/1455 cm À1 (ν 9 ) accompanied by a shoulder at 1484 (w)/1488 cm À1 (ν 18 ).…”

Section: Nh Fundamentalssupporting

confidence: 91%

“…QM theoretical predictions of the vibrational spectra normally assist in vibrational assignment and structural elucidation, [ 49a,52 ] therefore the IR and Raman spectra were simulated for enol ‐HNP and keto ‐NPO tautomers. For this purpose, the B3LYB/6‐311++G(d,p) scaled frequencies combined with calculated IR intensities and Raman activities have been used in a plot program written in C language [ 53 ] ; see Figures 1b,c and 2c,d (HNP/NPO) for simulated Raman and IR spectrum, respectively.Raman intensities were theoretically obtained from the Raman scattering cross‐sections, which were computed using the predicted scattering activities and scaled wavenumbers for each normal mode.…”

Section: Resultsmentioning

confidence: 99%

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2‐Hydroxy‐5‐nitropyridine and 5‐nitro‐2‐pyridone: Tautomerism, infrared, Raman, and NMR spectral interpretations, normal coordinate analysis, and DFT calculations

Mohamed

Shaaban

Soliman

et al. 2021

J Chinese Chemical Soc

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Raman (3700-50 cm À1 ) and infrared (IR) (4000-230 cm À1 ) spectra of 2-hydroxy-5-nitropyridine (HNP; C 5 H 4 N 2 O 3 ) have been recorded in the solid phase in addition to 1 H, 13 C, and 15 N nuclear magnetic resonance (NMR) spectra of the sample in dimethyl sulfoxide-d 6 (DMSO-d 6 ). Initially, keto and enol tautomeric forms were proposed owing to proton transfer from the hydroxyl group to pyridine nitrogen atom. Quantum mechanical calculations based on density functional theory (DFT; B3LYP, ωB97XD, and mPW1PW91) were carried out using 6-31G(d) and 6-311++G(d,p) basis sets favoring keto-NPO, 5-nitro-2-pyridone, tautomer by $0.857-1.345 kcal/mol with minor enol-HNP in the gas phase. Moreover, 1 H, 13 C, and 15 N NMR chemical shifts were predicted using gauge-invariant atomic orbital-DFT calculation at 6-311++G (d,p) basis set using integral equation formalism of the polarization continuum solvation model including solvent effects. The calculated chemical shifts and spin-spin coupling constants (J HH ) for keto tautomer better resemble those experimentally observed rather than the enol form. The observed IR/Raman bands were assigned quantitatively to their normal modes based on the calculated vibrational frequencies, force constants in internal coordinates, normal coordinate analysis, and potential energy distributions. Finally, the nitro and hydroxyl barriers to internal rotations were predicted via a relaxed potential energy surface scan using B3LYP/6-311++G(d,p) calculations. The results are reported herein and compared with similar molecules whenever appropriate.

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Section: Resultssupporting

confidence: 88%

Section: Nh Fundamentalssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

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2‐Hydroxy‐5‐nitropyridine and 5‐nitro‐2‐pyridone: Tautomerism, infrared, Raman, and NMR spectral interpretations, normal coordinate analysis, and DFT calculations

Mohamed

Shaaban

Soliman

et al. 2021

J Chinese Chemical Soc

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“…Due to their essential role in biological and chemical processes and its importance in understanding their mechanisms caused considerable experimental and theoretical attention [7][8][9]. Several theoretical and experimental studies were performed to warble the information concerning H-transfer mechanism and properties relevant to such tautomeric-equilibrium processes [10][11][12][13][14]. The tautomeric single H-transfer in many compounds, determining the thiol-thione favoured structure was concerned in several areas of biochemistry, pharmacy and chemistry [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Untitled

Razavi

2020

J. Med. Chem. Sci.

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This study discussed the prediction of tautomerization manner of the 1,4bis(methane sulfonyloxy)butane in chemical reactions with an excellent and accurate quantum methods in gas phase. H transition and H migration for the O-H to nearby C=S was theoretically elaborated. The thione tautomer isomer structure formation was investigated as a novel work in recent years. The accurate energy of optimized molecule structures in gas-phase was surveyed by two basis sets of 6-31++G(d) and 6-31++G (d,p) to determine the best reactivity in the biochemical and chemical media. According to the defined computational results, the 1,4-bis(methane sulfonyloxy)butane has been followed by three reactions. Activation and formation energy of reaction was calculated and showed logical way to tautomerization manner. Three predicted reactions state that dissociation of 1,4-bis(methane sulfonyloxy)butane to alkene and sulfonyloxy functional groups is more occruable than tautomer transition in chemical and biochemical media.

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“…The Density Functional Theory (DFT) and Hartree Fock (HF) methods have been significantly used for the calculation of many parameters of some 4,5-dihydro-1H-1,2,4-triazol-5-one derivatives such as structural and spectral parameters; 1 H-and 13 C-NMR, FT-IR, UV-Vis spectra, HOMO-LUMO energies, Mulliken atomic scharge distributions, thermodynamics and electronic properties. In the literature, the appropriate HF and DFT quantum chemical calculations have been carried out and the findings obtained from the experimental techniques were assessed [17][18][19][20][21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Investigations of Structural Properties, Spectroscopic Aspects, Electronic and Thermodynamic Properties of 3-Benzyl-4-[3-(3-methoxybenzoxy)-benzylidenamino]-4,5-Dihydro-1H-1,2,4-Triazol-5-one with DFT/HF Basis Sets

Medetalibeyoğlu

Yüksek

2019

Bilecik Şeyh Edebali Üniversitesi Fen Bilimleri Dergisi

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Bu makalede, öncelikle 3-benzil-4-[3-(3-metoksibenzoksi)-benzilidenamino]-4,5-dihidro-1H-1,2,4-triazol-5on(1)'un sentezi, FT-IR, NMR kimyasal kaymaları, UV-Vis spektral değerleri incelenmiştir. Daha sonra, molekül 6-311G(d)/3-21G temel setleriyle B3LYP ve HF yöntemleri kullanılarak optimize edilmiştir. Molekülün, elektronik ve termodinamik parametreleri, geometrik ve yapısal özellikleri, HOMO-LUMO enerji değerleri, moleküler elektrostatik potansiyeli (MEP) ve Mulliken atomik yükleri oluşturulmuştur. Bu molekülün 1 H-NMR ve 13 C-NMR kimyasal kayma değerleri (DMSO çözücüsünde ve temel durumda) GIAO yöntemiyle gerçekleştirilmiştir. Molekülün, geometrik ve spektroskopik parametreleri, 6-311G(d) ve 3-21G temel setleriyle yoğunluk fonksiyoneli (DFT/B3LYP) ve Hartree-Fock (HF) yöntemleri kullanılarak oluşturulmuştur. Ayrıca, FT-IR değerlerinin tayin edilmesinde veda4f yazılım programı kullanılmıştır. UV-vis verileri (etanol ortamında) hesaplanmış ve tüm spektral parametreler deneysel verilerle karşılaştırılmıştır.

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Raman, infrared and NMR spectral analysis, normal coordinate analysis and theoretical calculations of 5-(methylthio)-1,3,4-thiadiazole-2(3H)-thione and its thiol tautomer

Cited by 17 publications

References 55 publications

2‐Hydroxy‐5‐nitropyridine and 5‐nitro‐2‐pyridone: Tautomerism, infrared, Raman, and NMR spectral interpretations, normal coordinate analysis, and DFT calculations

2‐Hydroxy‐5‐nitropyridine and 5‐nitro‐2‐pyridone: Tautomerism, infrared, Raman, and NMR spectral interpretations, normal coordinate analysis, and DFT calculations

Untitled

Investigations of Structural Properties, Spectroscopic Aspects, Electronic and Thermodynamic Properties of 3-Benzyl-4-[3-(3-methoxybenzoxy)-benzylidenamino]-4,5-Dihydro-1H-1,2,4-Triazol-5-one with DFT/HF Basis Sets

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