scholarly journals Specific Far Infrared Spectroscopic Properties of Phospholipids

2012 ◽  
Vol 27 ◽  
pp. 525-532 ◽  
Author(s):  
Ruth Hielscher ◽  
Petra Hellwig
Keyword(s):  
Hydrogen Bonding ◽  
Far Infrared ◽  
Spectroscopic Properties ◽  
Spectral Signature ◽  
Head Group ◽  
Group Contributions ◽  
Hydrocarbon Chains ◽  
Infrared Spectroscopic ◽  
Skeleton Vibration

We describe the specific spectral signature of different phospholipids and sphingolipids in the far infrared. Three specific spectral domains have been found: the head group contributions (600 and 480 cm−1); the modes of the torsion motion of the hydrocarbon chains and of the skeleton vibration (460 to 180 cm−1); and the hydrogen-bonding continuum (below 300 cm−1). Marker bands for individual phospholipids are distinguished.

High-Pressure Far-Infrared Spectroscopic Studies of Hydrogen Bonding in Formic Acid

2013 ◽  
Vol 67 (9) ◽  
pp. 1080-1086 ◽  
Author(s):  
Virginia W. Manner ◽  
Raja S. Chellappa ◽  
Stephen A. Sheffield ◽  
Zhenxian Liu ◽  
Dana M. Dattelbaum
Keyword(s):  
High Pressure ◽  
Hydrogen Bonding ◽  
Formic Acid ◽  
Far Infrared ◽  
Spectroscopic Studies ◽  
Infrared Spectroscopic

Liquid-helium-cooled Fabry-Perot spectrometer and the frequency switching method for far-infrared spectroscopic observations

1990 ◽  
Author(s):  
Takao Nakagawa ◽  
Haruyuki Okuda ◽  
Hiroshi Shibai ◽  
Hideo Matsuhara ◽  
Yukiyasu Kobayashi ◽  
...  
Keyword(s):  
Liquid Helium ◽  
Far Infrared ◽  
Spectroscopic Observations ◽  
Fabry Perot ◽  
Infrared Spectroscopic ◽  
Switching Method

scholarly journals QM AND AB INITIO INVESTIGATION ON THE HYDROGEN BONDING, NMR CHEMICAL SHIFTS AND SOLVENT EFFECTS ON THE DPPE

2010 ◽  
Vol 7 (3) ◽  
pp. 260-272
Author(s):  
M. Monajjemi ◽  
A. Nouri ◽  
H. Monajemi
Keyword(s):  
Hydrogen Bonding ◽  
Ab Initio ◽  
Atomic Orbital ◽  
Theoretical Data ◽  
Basis Sets ◽  
Stable Complex ◽  
Head Group ◽  
Water Molecules ◽  
Hartree Fock ◽  
Zwitterionic Form

The hydrogen bonding effects that were produced from interaction of membrane lipid dipalmitoylphosphatidyl-ethanolamine (DPPE) with 1-5 water molecules, has been theoretically  investigated through the quantum mechanical calculations at the Hartree-Fock level of theory and the 3-21G, 6-31G and 6-31G* basis sets with the computational package of Gaussian 98. According to the obtained results of the structural optimization of the isolated DPPE in the gas phase, we can see the evidences of interactions in the head group of this macromolecule (from the molecular point of view we have a proton transfer from the ammonium group to the phosphate oxygen of zwitterionic form. As we know that the hydrogen bonding of DPPE with water molecules which have surrounded its head group plays an important role in the permeability of DPPE. So, in order to understand the microscopic physico-chemical nature of this subject we have analyzed bond and torsion angles of DPPE before and after added water molecules.  In this paper we have theoretically studied the complexes DPPE with water molecules which have surrounded its head group. As mentioned before, this theoretically study has been done through Hartree-Fock level of theory by using simple basis sets. Theoretical data shows that the interaction of head group of DPPE with water molecules causes some changes in the geometry of DPPE which were explained by the contribution of zwitterionic form of DPPE macromolecule, and finally hydrated DPPE becomes stable complex. Comparison between theoretical and experimental geometry data of DPPE macromolecule shows that the calculation at the HF/3-21 level of theory produces results which they are in better agreement with the experimental data. Moreover the hydrogen bonding effects on the NMR shielding tensor of selected atoms in the hydrated complexes of DPPE were reported. The ";Gauge Including Atomic Orbitals"; (GIAO) approaches within the SCF-Hartree-Fock approximation have been used in order to investigate the influence of hydrogen bonding of DPPE-water complex on the shielding tensors. Finally, the solvent affects on the stability of DPPE macromolecule, dipole moment and atomic charge of some selected atoms of DPPE molecule was discussed using Onsager model and Merz-Singh-Kolman schema.   Keywords  : Gauge Including Atomic Orbital, DPPE, hydrogen bonding, solvation, quantum mechanics, ab initio

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