Vibrational Spectroscopy

Hsu, Shaw Ling

doi:10.1002/0471440264.pst381

Cited by 4 publications

(14 citation statements)

References 198 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This resonance can result in much enhanced intensity of overtone band through the borrowing of the intensity from the fundamental band. 10,12 In principle, the smaller the difference in the two vibrational levels is, the greater the resonance becomes. As a result, small changes in the frequency of the fundamental vibration may cause significant changes in the overtone spectral profile.…”

Section: Introductionmentioning

confidence: 99%

“…As a result, small changes in the frequency of the fundamental vibration may cause significant changes in the overtone spectral profile. 10,12 In theory, the Fermi resonant interactions can be explained as a combined effect of molecular anharmonicity of an isolated molecule and the intermolecular interaction potential between the single molecule and its neighboring molecules. 13−20 For the same isolated molecule, the molecular anharmonicity and the zero-order state energy will be the same.…”

Section: Introductionmentioning

confidence: 99%

“…The intensity ratio of the ν 1 and 2ν 2 bands (R 2ν 2 /ν 1 = I 2ν 2 /I ν 1 ) has been used for quantifying the intermolecular interaction by Raman spectra. 10,12 We could anticipate that the second-order Fermi resonant signals, provided by surface-sensitive sum frequency generation vibrational spectroscopy (SFG-VS), might permit to obtain the interfacial interaction force. To materialize this idea, here we used phospholipids such as phosphatidic acid (PA) and phosphocholine as the models, to carry out the first detailed study on the correlation between the total interfacial molecular interactions and the second-order Fermi resonant signals.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Intermolecular Interactions at the Interface Quantified by Surface-Sensitive Second-Order Fermi Resonant Signals

Tian

Zhang

et al. 2015

J. Phys. Chem. C

View full text Add to dashboard Cite

Accurate determination of intermolecular interaction forces at the surface and the interface is essential to identify the nature of interfacial phenomena such as absorption, interfacial assembly, and specific ion effect, but it still represents a major technical challenge. In this study, we proposed a novel method to deduce the interfacial interaction forces by using surface-sensitive second-order Fermi resonant signals, generated in sum frequency generation vibrational spectroscopy (SFG-VS). By investigating the influence of lipid chain length and intermolecular distance on the Fermi resonant signals of phospholipid monolayer at the air/CaF 2 surface and the air/water interface, a linear correlation between the Fermi resonant intensity ratio and the dominated interactions in the lipid monolayer has been observed. It implies that the amplitude of the intensity ratio can be used as an effective in situ vibrational optical ruler to characterize the total intermolecular interaction forces at the surface and the interface. Such a relationship further enables us to elucidate the specific ion effects on the interfacial interactions, allowing us to identify different contributions from van der Waals, electrostatic, and hydration interactions. This study clearly demonstrates the power of the second-order Fermi resonant signals for evaluating the interfacial interaction forces in situ and in real time.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Intermolecular Interactions at the Interface Quantified by Surface-Sensitive Second-Order Fermi Resonant Signals

Tian

Zhang

et al. 2015

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…Here, we are interested in the early "glassy" elastic regime, observed above GT at times shorter than the structural relaxation time τ α . Our interest is motivated by recent development in vibrational spectroscopy 14 and especially Terahertz spectroscopy which evidenced both a strikingly similar response for a wide range of disordered systems of the dielectric response of the vibrational density of states 15,16 and coupling with mechanical properties in polymers 17 , nanocomposites 18,19 and pharmaceuticals 20 . We address two aspects concerning both G ∞ and G p which will be compared to the features of the elastic response below GT , namely the influence of the chainlength and the roles played by the bonded and non-bonded interactions.…”

Section: Introductionmentioning

confidence: 99%

Short-time elasticity of polymer melts: Tobolsky conjecture and heterogeneous local stiffness

Bernini

Leporini

2015

J. Polym. Sci. Part B: Polym. Phys.

View full text Add to dashboard Cite

An extended Molecular-Dynamics study of the short-time "glassy" elasticity exhibited by a polymer melt of linear fully-flexible chains above the glass transition is presented. The focus is on the infinite-frequency shear modulus G ∞ manifested in the picosecond time scale and the relaxed plateau G p reached at later times and terminated by the structural relaxation. The local stiffness of the interactions with the first neighbours of each monomer exhibits marked distribution with average value given by G ∞ . In particular, the neighbourhood of the end monomers of each chain are softer than the inner monomers, so that G ∞ increases with the chain length. G p is not affected by the chain length and is largely set by the non-bonding interactions, thus confirming for polymer melts the conjecture formulated by Tobolsky for glassy polymers.

show abstract

“…Here, Fermi resonance interaction is an intramolecular coupling between a fundamental vibration (ν 1 ) and an overtone band (2ν 2 ) of another vibration that has the same symmetry and nearly the same energy . Fermi resonant interaction is highly sensitive to the small conformation change of a molecule caused by the interactions between the molecule and its environment. − A change in the Fermi resonant interaction can be used to estimate the change in the total intermolecular interactions. − We have demonstrated the power of this new technique in the study of specific ion effects on the interfacial interactions. Different contributions from the van der Waals (vdW) interaction, the electrostatic interaction, and the hydration interaction can be identified for ion in lipids .…”

Section: Introductionmentioning

confidence: 99%

Fermi Resonant Interaction of the Tailed Methyl Groups of Langmuir Monolayer at the Air/Water Interface during Phase Transition

Tian

2015

J. Phys. Chem. C

View full text Add to dashboard Cite

Molecular insight into the interactions of two-dimensional (2D) materials at the interface is essential to understand the functionality of interfacial molecular devices. Yet it still remains elusive so far. Fermi resonant interaction is highly sensitive to the total molecular interactions. In this study, we used lipid 1,2-dimyristoylsn-glycero-3 -phospho-(1′-rac-glycerol) (sodium salt) (DMPG) monolayer as a model, and performed a systematic study to investigate the Fermi resonant interactions of 2D materials at the interface during liquid-expanded (LE) to liquid-condensed (LC) phase transition using multiplexed-polarization sum frequency generation vibrational spectroscopy (SFG-VS). It is found that the ratio (R 1 ) between Fermi resonance and symmetric stretching mode of the tailed methyl groups sharply decreases during the phase transition. The sharp drop of R 1 originates from the nonsynchronous change of the tail and head groups of the lipid. The tailed CH 3 groups of DMPG locally accumulate at the air/water interface during LE− LC phase transition while the head glycerol groups do not. The local aggregation of the methyl groups strengthens the van der Waals (vdW) interaction, leading to the decrease of the total intermolecular interactions and the drop of the ratio of R 1 . However, such phenomena are not observed at the air/KCl solution (0.3M) interface.

show abstract

Vibrational Spectroscopy

Cited by 4 publications

References 198 publications

Intermolecular Interactions at the Interface Quantified by Surface-Sensitive Second-Order Fermi Resonant Signals

Intermolecular Interactions at the Interface Quantified by Surface-Sensitive Second-Order Fermi Resonant Signals

Short-time elasticity of polymer melts: Tobolsky conjecture and heterogeneous local stiffness

Fermi Resonant Interaction of the Tailed Methyl Groups of Langmuir Monolayer at the Air/Water Interface during Phase Transition

Contact Info

Product

Resources

About