Synthesis and characterization of partially fluorinated stearolic acid analogs: Effect of their fluorine content on the monolayer at the air–water interface

Synthesis and monolayer properties of double-chained phosphatidylcholines containing perfluoroalkyl groups of different length

“…It is noteworthy that the monolayer stability of non-fluorinated PC counterpart 1e and CF 3 -termenated PC 1a is unexpectedly almost the same in contrast with a series of fluorinated stearolic acids, where the introduction of terminal CF 3 -group significantly raises the equilibrium surface pressure of stearolic acid at 25 8C [25]. One factor affecting the relationship between the value of p e and the fluorinated carbon number should be a difference in the bulk state, i.e., hydrated stearolic acid and its CF 3 -terminated analog are in the solid state at the air-water interface while the more fluorinated stearolic acid analogs and all of the PCs in this study are considered to be in the liquid one.…”

“…The fluorinated stearolic acids 2a-d, the corresponding nonfluorinated counterpart, i.e., stearolic acid (2e), and (R)-3-O-(4 0 -methoxybenzyloxy)-1,2-propanediol (3) were provided by a known procedure [23][24][25][26]. The esterification of 2a-e with 3 proceeded at room temperature in the presence of N, N 0 -dicyclohexyl carbodiimide (DCC) to afford 4a-e in high yields.…”

“…We have already reported the synthesis of a series of fluorinated C 18 fatty acids with monoyne bond, i.e., fluorinated stearolic acids containing F(CF 2 ) n (n = 1, 2, 3,4,8), and estimated their monolayer stability by measuring their equilibrium spreading pressures, p e s, at the air-water interface and at 25 8C. Under this condition, the replacement of at least five hydrogen atoms at the terminal hydrophobic segment in stearolic acid molecule by fluorine atoms (CF 3 CF 2 group) was required to alter the bulk property of stearolic acid and exhibit the monolayer stabilizing effect, whereas further fluorination of stearolic acid (F(CF 2 ) n ; n > 4) had a minor effect on the monolayer stability [24,25].…”

Dynamic Molecular Behavior of Semi-Fluorinated Oleic, Elaidic and Stearic Acids in the Liquid State

“…However, ESP for SF-acid is always larger than that for its corresponding H-acid. Takai et al 28 . also reported the effect of fluorine content in the hydrophobic chain on the ESP of stearolic acid analogs containing shorter perfluoroalkyl groups, such as CF 3 , C 2 F 5 , n-C 3 F 7 , n-C 4 F 9 or n-C 8 F 17 at the air-water interface: An increase in fluorine-content in a stearolic acid molecule increases its ESP value.…”

“…On the other hand, Takai et al 28 reported that an introduction of a fluorinated group such as CF 3 , C 2 F 5 , C 3 F 7 , or C 4 F 9 in a terminal acyl group of stearolic acid decreases its melting temperature. The difference in the melting temperature tendency between SFacids and stearolic acid analogs may be correlated with the difference in bonding structure such as a double bond or triple bond.…”