Near-infrared spectra of Ba(NO2)2•X2O (X = H,D) at 10 K. A local-mode approach

1997 ◽  
Vol 75 (8) ◽  
pp. 1099-1105 ◽  
Author(s):  
Ian M. Walker ◽  
Paul J. McCarthy
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Fermi Resonance ◽  
Strong Hydrogen Bond ◽  
Local Mode ◽  
Morse Oscillator ◽  
Near Infrared Spectra ◽  
Bifurcated Hydrogen Bond

The fundamental and overtone vibrational spectra of Ba(NO2)2•X2O (X=H,D) have been interpreted using the local mode model. The calculated parameters are consistent with the structure, which has one strong hydrogen bond and one weak bifurcated hydrogen bond. Evidence for Fermi resonance between stretch and bend features having similar energies is discussed. Evidence for the breakdown of the simple Morse oscillator model, which was quite successful for [Formula: see text] hydrogen bonds, is also presented. Keywords: overtone, spectra, near-infrared, hydrates, local-mode model.

"Transitions vibrationnelles simultanées" d'un donneur et d'un accepteur de proton

1973 ◽  
Vol 51 (12) ◽  
pp. 2059-2070 ◽  
Author(s):  
André Burneau ◽  
Jacques Corset
Keyword(s):  
Hydrogen Bond ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Proton Donor ◽  
Strong Hydrogen Bond ◽  
Intensity Increase ◽  
Absorption Bands ◽  
Near Infrared Spectra ◽  
Weak Hydrogen Bonds ◽  
Proton Donors

Absorptions simultaneously involving the vibrations of two molecules are brought out of the near infrared spectra of mixtures containing a proton donor RXH and an acceptor R′AB. The donors under study are: chloroform, water, pentachlorophenol, and methanol, and the acceptors: acetonitrile, acetone, dimethylsulfoxide, and pyridine; for comparison, carbon disulfide and hexachloracetone are also used as solvents. Not only the combinations vXH + vAB and vXH + v3(CS2) are observed, but also vXH + vR′, at about 6500 cm−1, if R′ contains CH bonds; these absorptions at 6500 cm−1 do not exist when fully deuterated bases R′AB are used. A correlation between the intensity increase, through hydrogen bonding, of the vXH bands and that of the simultaneous transitions is suggested by the results. In the assignment of the near infrared spectra of proton donors, it is important to take into account the simultaneous transitions because their intensity is sometimes greater than that of the overtones 2vXH. It is likely that these conclusions, founded on the study of relatively weak hydrogen bonds, may be extended to stronger interactions; but the width of the absorption bands in the case of strong hydrogen bond makes the observation of the simultaneous transitions difficult.

Single crystal polarized spectra in the near-infrared region: a local-mode analysis of the spectra of CsMnCl3•2X2O (X = H, D)

1994 ◽  
Vol 72 (5) ◽  
pp. 1211-1217 ◽  
Author(s):  
Ian M. Walker ◽  
Paul J. McCarthy
Keyword(s):  
Hydrogen Bond ◽  
Near Infrared ◽  
Infrared Region ◽  
Chloride Ions ◽  
Mode Analysis ◽  
Local Mode ◽  
Local Modes ◽  
Near Infrared Spectra ◽  
Parameter Values ◽  
Local Mode Analysis

Polarized near-infrared spectra of single crystals of CsMnCl3•2X2O (X = H, D) were recorded at 10 K. Those bands which could be assigned to O—H or O—D stretch overtones were analyzed using local-mode theory specifically adapted for systems having less than C2v symmetry. Both O—H oscillators form nearly linear hydrogen bonds to neighboring chloride ions at different distances. As a result, the local-mode harmonic frequency and anharmonicity parameters show characteristic shifts from their gas-phase values. The parameter values cover an unusually narrow range in this crystal, considering the spread in hydrogen-bond distances. Assignment of stretch overtone bands to specific oscillators in the crystal was made by using the polarization behavior expected of local modes in the oriented gas model. Several of the overtone bands show combinations with lattice modes or low-energy hydrogen-bond modes in unusual detail.

scholarly journals Water Adsorption Properties of Free and Dehydrated β-Cyclodextrin Studied by near Infrared Spectroscopy and Gravimetry

2016 ◽  
Vol 689 ◽  
pp. 143-147 ◽  
Author(s):  
Alfred A. Christy
Keyword(s):  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Water Adsorption ◽  
Near Infrared ◽  
Adsorption Properties ◽  
Water Molecules ◽  
Hydroxyl Groups ◽  
Oh Groups ◽  
Near Infrared Spectra ◽  
Adsorption Of Water

β-cyclodextrin, like other carbohydrates has a tendency to adsorb water molecules and the properties are attributed to the hydroxyl groups in the molecules. β-cyclodextrin, the cyclic oligomer of glucose has a hydrophobic interior and hydrophilic exterior. The cyclic structure favours the formation of hydrogen bonds between the OH groups on the adjacent glucose units and affects the formation of hydrogen bonds with water molecules. The hydoxyl groups engaged in hydrogen bondings can be eliminated at high temperatures and the adsorption properties of the dehydrated β-cyclodextrin will depend on the new functional groups formed. The aim of the report is to discuss the issue of the water adsorption properties of free and dehydrated β-cyclodextrin. Dry β-cyclodextrin and dehydrated β-cyclodextrin at temperatures 250, 300 and 350 °C were allowed to adsorb water from a humidity controlled air environmennt and the evolving near infrared spectra were measured using a near infrared spectrometer equipped with a transflectance accessory. The near infrared spectra in the region 10,000-4000 cm-1 and their second and fourth derivative profiles were used in studying the variation in the adsorption characteristics of dehydrated β-cyclodextrin. The results of the analyses show that the adsorption of water by β-cyclodextrin decreses at 300 °C compared to 200 and 250 °C. Dehydration forms more of the ethereal type-O-bonds in the molecule and explains the decrease in the water molecular adsorption at higher dehydration temperatures.

The near-infrared spectra of some simple aldehydes

1970 ◽  
Vol 48 (23) ◽  
pp. 3694-3703 ◽  
Author(s):  
G. Lucazeau ◽  
C. Sandorfy
Keyword(s):  
Liquid Nitrogen ◽  
Infrared Spectra ◽  
Solvent Effects ◽  
Near Infrared ◽  
Fermi Resonance ◽  
Near Infrared Spectra ◽  
Anharmonicity Constants

The near-infrared spectra of CH3CHO, CD3CHO, CH3CDO, CF3CHO, CHCl2CHO, and CCl3CHO were measured from 4000 to 9000 cm−1 in solution at room and liquid nitrogen temperatures. Assignments are made and cases of Fermi resonance are examined. A few potential and anharmonicity constants are obtained. Solvent effects affecting fundamentals and overtones are discussed.

Short-Wave near Infrared Spectra of Organic Liquids

1993 ◽  
Vol 1 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Anthony S. Bonanno ◽  
Peter R. Griffiths
Keyword(s):  
Molecular Structure ◽  
Qualitative Analysis ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Short Wave ◽  
Organic Liquids ◽  
Local Mode ◽  
Near Infrared Spectra ◽  
Vibrational Transitions

Multi-quanta vibrational transitions are discussed in terms of the local mode model in order to develop a better understanding of the features observed in the short-wave near infrared (700–1100 nm) spectra of organic liquids. It is demonstrated that the spectra of simple alkanes and alcohols exhibit local mode features, and that these features are characteristic of molecular structure and will, therefore, be useful for quantitative and qualitative analysis.

Intramolecular Hydrogen Bonds and Fermi Resonance in N-Substituted N'-(2-Fluorobenzoyl)thiourea Derivatives

1994 ◽  
Vol 59 (4) ◽  
pp. 951-956 ◽  
Author(s):  
Oľga Hritzová ◽  
Dušan Koščík
Keyword(s):  
Hydrogen Bond ◽  
Perturbation Theory ◽  
Hydrogen Bonds ◽  
Bond Strength ◽  
Infrared Spectra ◽  
Fermi Resonance ◽  
Absorption Bands ◽  
Thiourea Derivatives ◽  
Hydrogen Bond Strength ◽  
Intramolecular Hydrogen

The presence of intramolecular NH...O=C bonds was proved in N-substituted N'-(2-fluorobenzoyl)thiourea derivatives by analysis of their infrared spectra. The intramolecular vibrational effects bring about a shift of the ν(NH) vibrational band to lower frequencies to the extent that the band gets into a vicinity to the δ(NH) overtone and Fermi resonance occurs between them. In addition, the ν(NH) vibration is also affected by Fermi resonance with the ν(CO) + δ(NH) combination. Double absorption bands were observed in the ν(CO) region for some of the derivatives. Based on perturbation theory applied to three-level interactions and using the Langseth and Lord equations, the band frequencies corrected for Fermi resonance were calculated and the hydrogen bond strength was examined in the compounds studied.

Single-crystal polarized spectra in the near-infrared region: a local-mode analysis of the spectra of M2MnCl4•2X2O (M = Cs, Rb; X = H, D)

1996 ◽  
Vol 74 (2) ◽  
pp. 246-253 ◽  
Author(s):  
Ian M. Walker ◽  
Paul J. McCarthy
Keyword(s):  
Hydrogen Bond ◽  
Single Crystal ◽  
Near Infrared ◽  
Infrared Region ◽  
Fermi Resonance ◽  
Mode Analysis ◽  
Local Mode ◽  
Bending Mode ◽  
Near Infrared Region ◽  
Local Mode Analysis

The polarized crystal spectra of M2MnCl4•2X2O (M = Cs, Rb; X = H, D) have been measured at 10 K in the near-infrared region. The data have been analyzed using a local-mode model that includes the bending mode. The resulting parameters are related to hydrogen bonding in the crystals. The spectra of partially deuterated species show a large number of bands due to HOD vibrations. The parameters from these spectra are compared to those from the H2O and D2O spectra. Arguments as to the importance of Fermi resonance in these spectra are presented. Key words: near-infrared, single crystal, hydrogen bond, Fermi resonance.

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