Ar-matrix IR spectra of 2-propanol and its OD, D7 and D8 isotopologues

Dobrowolski, Jan Cz.; Ostrowski, Sławomir; Kołos, Robert; Jamróz, Michał H.

doi:10.1016/j.vibspec.2007.12.017

Cited by 27 publications

(38 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the contrary, in the Ar-matrix IR study, the bands at 2884 cm À1 was attributed to CH group, whereas the band at 2933 cm À1 was attributed to CH 3 group. [24] Here, our results clearly show that those two kinds of assignments are not complete.…”

Section: Dft Calculationsmentioning

confidence: 66%

“…[24] However, we notice that their IR assignment is in disagreement with that from SFG method at the air/2-propanol interface. For example, the same peak at 2880 cm À1 was assigned to the CH stretching vibration in matrix, whereas it was attributed to CH 3 stretching at the interface.…”

Section: Introductionmentioning

confidence: 66%

“…At the present theoretical level, the gauche conformer is more stable than the trans by an energy difference of 0.19 kcal/mol (the energy value is zero point corrected), which is more consistent with that of 0.18 kcal/mol from focal point calculations but larger than that of 0.02 kcal/mol from CCSD(T)/cc-pVTZ. [24,32] The calculated Raman spectra are presented in Fig. 3, where only the spectrum of normal 2-propanol in the selected regions of C-H bending and stretching are displayed.…”

Section: Calculated Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Overlapping spectral features and new assignment of 2‐propanol in the C–H stretching region

Wang

et al. 2014

J Raman Spectroscopy

View full text Add to dashboard Cite

The vibrational spectra of gaseous and liquid 2-propanol in the C-H stretching region of 2800~3100 cm À1 were investigated by polarized photoacoustic Raman spectroscopy and conventional Raman spectroscopy, respectively. Using two deuterated samples, that is, CH 3 CDOHCH 3 and CD 3 CHOHCD 3 , the overlapping spectral features between the CH and CH 3 groups were identified. With the aid of depolarization ratio measurements and density functional theory calculations, a new spectral assignment was presented. In the gas phase, the band at 2884 cm À1 was assigned to the overlapping of one CH 3 Fermi resonance mode and a CH stretching of gauche conformer. The bands at 2917 and 2933 cm À1 were assigned to another two CH 3 Fermi resonance modes, but the latter includes weak contribution from CH stretching of trans conformer. The bands at 2950 and 2983 cm À1 were assigned to CH 3 symmetric and antisymmetric stretching, respectively. The spectral features of liquid 2-propanol are similar to those in the gas phase except for the blue shift of CH and the red shift of CH 3 band positions, which can be attributed to the intermolecular interaction in the liquid state. The new assignments not only clarify the confusions in previous studies from different spectral methods but also provide the reliable groundwork on spectral application of 2-propanol in the futures.

show abstract

Section: Dft Calculationsmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 66%

Section: Calculated Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Overlapping spectral features and new assignment of 2‐propanol in the C–H stretching region

Wang

et al. 2014

J Raman Spectroscopy

View full text Add to dashboard Cite

show abstract

“…At 150 K rotational temperature, this leads to a column density correction factor of 1.26 from thermal population of the anti conformer. Taking into account vibrational data from Inagaki et al (1973) and Dobrowolski et al (2008) yields a combined conformational and vibrational correction factor to the partition function of ∼1.86.…”

Section: Iso-propanol I-c 3 H 7 Ohmentioning

confidence: 99%

Exploring molecular complexity with ALMA (EMoCA): Alkanethiols and alkanols in Sagittarius B2(N2)

Müller

Беллоче

et al. 2016

A&A

131

157

View full text Add to dashboard Cite

Context. Over the past five decades, radio astronomy has shown that molecular complexity is a natural outcome of interstellar chemistry, in particular in star forming regions. However, the pathways that lead to the formation of complex molecules are not completely understood and the depth of chemical complexity has not been entirely revealed. In addition, the sulfur chemistry in the dense interstellar medium is not well understood. Aims. We want to know the relative abundances of alkanethiols and alkanols in the Galactic center source Sagittarius B2(N2), the northern hot molecular core in Sgr B2(N), whose relatively small line widths are favorable for studying the molecular complexity in space. Methods. We investigated spectroscopic parameter sets that were able to reproduce published laboratory rotational spectra of ethanethiol and studied effects that modify intensities in the predicted rotational spectrum of ethanol. We used the Atacama Large Millimeter Array (ALMA) in its Cycles 0 and 1 for a spectral line survey of Sagittarius B2(N) between 84 and 114.4 GHz. These data were analyzed by assuming local thermodynamic equilibrium (LTE) for each molecule. Our observations are supplemented by astrochemical modeling; a new network is used that includes reaction pathways for alkanethiols for the first time. Results. We detected methanol and ethanol in their parent 12 C species and their isotopologs with one 12 C atom substituted by 13 C; the latter were detected for the first time unambiguously in the case of ethanol. The 12 C/ 13 C ratio is ∼25 for both molecules. In addition, we identified CH OH ratio of ∼7.3. Upper limits were derived for the next larger alkanols normal-and iso-propanol. We observed methanethiol, CH 3 SH, also known as methyl mercaptan, including torsionally excited transitions for the first time. We also identified transitions of ethanethiol (or ethyl mercaptan), though not enough to claim a secure detection in this source. The ratios CH 3 SH to C 2 H 5 SH and C 2 H 5 OH to C 2 H 5 SH are 21 and 125, respectively. In the process of our study, we noted severe discrepancies in the intensities of observed and predicted ethanol transitions and propose a change in the relative signs of the dipole moment components. In addition, we determined alternative sets of spectroscopic parameters for ethanethiol. The astrochemical models indicate that substantial quantities of both CH 3 SH and C 2 H 5 SH may be produced on the surfaces of dust grains, to be later released into the gas phase. The modeled ratio CH 3 SH/C 2 H 5 SH = 3.1 is lower than the observed value of 21; the model value appears to be affected most by the underprediction of CH 3 SH relative to CH 3 OH and C 2 H 5 OH, as judged by a very high CH 3 OH/CH 3 SH ratio. Conclusions. The column density ratios involving methanol, ethanol, and methanethiol in Sgr B2(N2) are similar to values reported for Orion KL, but those involving ethanethiol are significantly different and suggest that the detection of ethanethiol reported toward Orion KL ...

show abstract

“…However, in the range of CH stretching vibration the spectrum is often complicated by complex Fermi resonances, and precise assignment is hardly possible. [42] We start the discussion from b(OH) vibration bands. Out of the three neighboring bands at 1229.8, 1224.2, 1216.3 cm À1 , the weakest one at 1216.3 cm À1 is assigned to the b(OH) vibrations of I, while the remaining two are assigned to the much more intense b(C2H 2 ;C3H 2 ) modes in IV and II, respectively (Table 4SI).…”

mentioning

confidence: 99%

IR Low‐Temperature Matrix and ab Initio Study on β‐Alanine Conformers

et al. 2008

Self Cite

View full text Add to dashboard Cite

For the first time the argon-matrix low-temperature FTIR spectra of beta-alanine are recorded. They reveal a quite complicated spectral pattern which suggests the presence of several beta-alanine conformers in the matrix. To interpret the spectra, the eighteen beta-alanine conformers, stable in the gas phase, are estimated at the B3LYP and MP2 levels combined with the aug-cc-pVDZ. Ten low-energy structures are reoptimized at the QCISD/aug-cc-pVDZ and B3LYP and MP2 levels by using the aug-cc-pVTZ basis sets. Assignment of the experimental spectra is undertaken on the basis of the calculated B3LYP/aug-cc-pVDZ anharmonic IR frequencies as well as careful estimation of the conformer population. The presence of at least three beta-alanine conformers is demonstrated. The detailed analysis of IR spectra points to the possible presence of five additional beta-alanine conformers.

show abstract

Ar-matrix IR spectra of 2-propanol and its OD, D7 and D8 isotopologues

Cited by 27 publications

References 23 publications

Overlapping spectral features and new assignment of 2‐propanol in the C–H stretching region

Overlapping spectral features and new assignment of 2‐propanol in the C–H stretching region

Exploring molecular complexity with ALMA (EMoCA): Alkanethiols and alkanols in Sagittarius B2(N2)

IR Low‐Temperature Matrix and ab Initio Study on β‐Alanine Conformers

Contact Info

Product

Resources

About