In situ FT-IR investigation of phospholipid monolayer phase transitions at the air water interface

1988 ◽  
Vol 110 (3) ◽  
pp. 712-718 ◽  
Author(s):  
Melody L. Mitchell ◽  
Richard A. Dluhy
Keyword(s):  
Phase Transitions ◽  
Water Interface ◽  
Phospholipid Monolayer ◽  
Air Water Interface ◽  
Ft Ir

In Situ Measurement of the FT-IR Spectra of Phospholipid Monolayers at the Air/Water Interface

1988 ◽  
Vol 42 (1) ◽  
pp. 138-141 ◽  
Author(s):  
Richard A. Dluhy ◽  
Norman A. Wright ◽  
Peter R. Griffiths
Keyword(s):  
Detailed Examination ◽  
In Situ Measurement ◽  
Surface Films ◽  
Water Interface ◽  
Monolayer Films ◽  
Air Water Interface ◽  
Monomolecular Films ◽  
Acyl Chains ◽  
Ft Ir

External reflection Fourier transform infrared spectroscopy has been applied to the in situ measurement of the infrared spectra of insoluble phospholipid monolayer films that were spread at the air/water interface. The spreading conditions for the phospholipids [1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)] were chosen to mimic those of liquid-condensed and liquid-expanded surface films, respectively. It is shown that the infrared reflection spectra can identify vibrations due to the hydrocarbon acyl chains, carbonyl ester, and phosphate groups for these monolayer films on water. Detailed examination of the frequencies and polarization properties of the C-H stretching region shows that the liquid-condensed DSPC acyl chains are in a rigid, mostly all-trans configuration, while the liquid-expanded DMPC acyl chains are highly fluid. The spectra demonstrate that the external reflection FT-IR experiment can differentiate between the physical conformation of monomolecular films when water is used as a reflective substrate.

scholarly journals Spin Crossover in Nickel(II) Tetraphenylporphyrinate via Forced Axial Coordination at the Air/Water Interface

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4155
Author(s):  
Alexander V. Shokurov ◽  
Daria S. Kutsybala ◽  
Andrey P. Kroitor ◽  
Alexander A. Dmitrienko ◽  
Alexander G. Martynov ◽  
...  
Keyword(s):  
Spin State ◽  
Spin Crossover ◽  
High Spin State ◽  
Water Interface ◽  
Metal Centers ◽  
Axial Coordination ◽  
Vis Spectroscopy ◽  
Air Water Interface ◽  
Nickel Cation

Coordination-induced spin crossover (CISCO) in nickel(II) porphyrinates is an intriguing phenomenon that is interesting from both fundamental and practical standpoints. However, in most cases, realization of this effect requires extensive synthetic protocols or extreme concentrations of extra-ligands. Herein we show that CISCO effect can be prompted for the commonly available nickel(II) tetraphenylporphyrinate, NiTPP, upon deposition of this complex at the air/water interface together with a ruthenium(II) phthalocyaninate, CRPcRu(pyz)2, bearing two axial pyrazine ligands. The latter was used as a molecular guiderail to align Ni···Ru···Ni metal centers for pyrazine coordination upon lateral compression of the system, which helps bring the two macrocycles closer together and forces the formation of Ni–pyz bonds. The fact of Ni(II) porphyrinate switching from low- to high-spin state upon acquiring additional ligands can be conveniently observed in situ via reflection-absorption UV-vis spectroscopy. The reversible nature of this interaction allows for dissociation of Ni–pyz bonds, and thus, change of nickel cation spin state, upon expansion of the monolayer.

Polymerization of a diacetylenic phospholipid monolayer at the air-water interface

1994 ◽  
Vol 4 (1) ◽  
pp. 37-58 ◽  
Author(s):  
L. Bourdieu ◽  
D. Chatenay ◽  
J. Daillant ◽  
D. Luzet
Keyword(s):  
Water Interface ◽  
Phospholipid Monolayer ◽  
Air Water Interface
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