Infrared spectroscopic investigation of complexes of ClF and Cl2 with crown ethers and related cyclic polyethers in argon matrices

Bai, Hebi; Ault, Bruce S.

doi:10.1016/0022-2860(89)85004-5

Cited by 10 publications

(7 citation statements)

References 28 publications

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“…The conclusion that 12c4 in the above-mentioned phases exists in the C i conformation was probably not reached before, according to the best of our knowledge, since a detailed vibrational analysis of free 12c4 did not receive a suitable attention. − This conclusion is in agreement with the previous X-ray study of solid 12c4 at −150 °C, but contradicts with the NMR study which could not indicate what conformation, or conformations, 12c4 exists in . This was attributed to the rapid interconversion of 12c4 between different conformations.…”

Section: Discussionmentioning

confidence: 56%

“…The number of studies of the vibrational spectra of 12c4 is quite limited with only a small number of vibrational bands assigned. − These studies were concerned mainly with the changes due complexation with different metal cations. Fukushima et al reported a Raman study of the vibrational spectra of 12c4 and some of its alkali metal and alkaline earth metal as well as NH 4 + complexes.…”

Section: Introductionmentioning

confidence: 99%

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Experimental and Theoretical Study of the Vibrational Spectra of Free 12-Crown-4

El-Azhary

Al-Kahtani

2005

J. Phys. Chem. A

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The Raman and IR spectra of free 12-crown-4 (12c4) were measured in the solid, liquid, and solution phases. In the three phases, IR active modes were Raman inactive and IR inactive modes were Raman active. According to the exclusion rule, this is consistent with a conformation with a center of inversion. This indicates that 12c4 in the above-mentioned three phases exists in the C(i) conformation. Harmonic force fields were calculated for five of the lowest energy conformations of 12c4 of C(i), S(4), C(4), C(2), and C(s) symmetries at the corresponding optimized geometries at the B3LYP/6-31+G level. The five force fields were scaled using a six-scale-factor scaling scheme. The scale factors were varied to minimize the difference between the calculated and experimental fundamental frequencies, except that corresponding to the C-H stretching mode that was held fixed. The root-mean-square (rms) deviation of the experimental to the calculated vibrational frequencies was 6.2, 12.0, 10.8, 13.2, and 13.5 cm(-1), for C(i)(), S(4), C(4), C(2), and C(s) conformations, respectively. This supports the above conclusion that 12c4 in the solid, liquid, and considered solution phases exists in the C(i) conformation.

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Section: Discussionmentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Study of the Vibrational Spectra of Free 12-Crown-4

El-Azhary

Al-Kahtani

2005

J. Phys. Chem. A

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“…8 Ault et al measured IR spectra of (18-crown-6)-ClF, -Cl 2 , -HF, and -HCl complexes in argon matrix. 9,10 In both cases, Raman and IR spectra become sharper and simpler than those at room temperature, suggesting that the cooling will be effective for shedding light on the details of the intermolecular interaction in the host-guest complexes, free from congested spectral features. Supersonic jet expansion is another powerful method for the cooling as well as for the solvent-free condition.…”

Section: Introductionmentioning

confidence: 99%

Structure of hydrated clusters of dibenzo-18-crown-6-ether in a supersonic jet—encapsulation of water molecules in the crown cavity

Kusaka

Inokuchi

Ebata

2008

Phys. Chem. Chem. Phys.

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The structure of dibenzo-18-crown-6-ether (DB18C6) and its hydrated clusters has been investigated in a supersonic jet. Two conformers of bare DB18C6 and six hydrated clusters (DB18C6-(H(2)O)(n)) were identified by laser-induced fluorescence, fluorescence-detected UV-UV hole-burning and IR-UV double-resonance spectroscopy. The IR-UV double resonance spectra were compared with the IR spectra obtained by quantum chemical calculations at the B3LYP/6-31+G* level. The two conformers of bare DB18C6 are assigned to "boat" and "chair I" forms, respectively, among which the boat form is dominant. All the six DB18C6-(H(2)O)(n) clusters with n = 1-4 have a boat conformation in the DB18C6 part. The water molecules form a variety of hydration networks in the boat-DB18C6 cavity. In DB18C6-(H(2)O)(1), a water molecule forms the bidentate hydrogen bond with the O atoms adjacent to the benzene rings. In this cluster, the water molecule is preferentially hydrogen bonded from the bottom of boat-DB18C6. In the larger clusters, the hydration networks are developed on the basis of the DB18C6-(H(2)O)(1) cluster.

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“…Surprisingly, as the number of studies of the vibrational spectra of free 12c4 is quite limited, − the number of studies of the vibrational spectra of its alkali metal cation complexes, to the best of our knowledge, is very scarce. , The most detailed study of the vibrational spectra of 12c4−alkali metal cation complexes was reported by Fukushima and Tamaki in 1987 . The authors reported the Raman spectra of the 12c4−Li + , −Na + , −K + , −NH 4 + , −Mg 2+ , −Ca 2+ , −Sr 2+ , −Ba 2+ , and −Pb 2+ complexes in the region below 1000 cm -1 .…”

Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Study of the Vibrational Spectra of 12-Crown-4−Alkali Metal Cation Complexes

2006

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The vibrational, Raman, and IR, spectra of the five 12-crown-4 (12c4) complexes with Li+, Na+, K+, Rb+, and Cs+ alkali metal cations were measured. Except for a small shift of the position of some bands in the vibrational spectra of the Li+ complex, the vibrational spectra of the five complexes are so similar that it is concluded that the five complexes exist in the same conformation. B3LYP/6-31+G* force fields were calculated for six of the eight predicted conformations in a previous report (J. Phys. Chem. A 2005, 109, 8041) of the 12c4-Li+, Na+, and K+ complexes that are of symmetries higher than the C1 symmetry. These six conformations, in energy order, are of C4, Cs, Cs, C(2v), C(2v), and Cs symmetries. Comparison between the experimental and calculated vibrational frequencies assuming any of the above-mentioned six conformations shows that the five complexes exist in the C4 conformation. This agrees with the fact that the five alkali metal cations are larger than the 12c4 ring cavity. The B3LYP/6-31+G* force fields of the C4 conformation of the Li+, Na+ and K+ complexes were scaled using a set of eight scale factors and the scale factors were varied so as to minimize the difference between the calculated and experimental vibrational frequencies. The root-mean-square (rms) deviations of the calculated frequencies from the experimental frequencies were 7.7, 5.6, and 5.1 cm(-1) for the Li+, Na+, and K+ complexes, respectively. To account for the earlier results of the Li+ complex that the Cs conformation is more stable than the C4 conformation by 0.16 kcal/mol at the MP2/6-31+G* level, optimized geometries of the complex were calculated for the C4 and Cs conformations at the MP2/6-311++G** level. The C4 conformation was calculated to be more stable than the Cs conformation by 0.13 kcal/mol.

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Infrared spectroscopic investigation of complexes of ClF and Cl2 with crown ethers and related cyclic polyethers in argon matrices

Cited by 10 publications

References 28 publications

Experimental and Theoretical Study of the Vibrational Spectra of Free 12-Crown-4

Experimental and Theoretical Study of the Vibrational Spectra of Free 12-Crown-4

Structure of hydrated clusters of dibenzo-18-crown-6-ether in a supersonic jet—encapsulation of water molecules in the crown cavity

Experimental and Theoretical Study of the Vibrational Spectra of 12-Crown-4−Alkali Metal Cation Complexes

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