Selective synthesis and self-organization at the air/water interface of long chain fluorinated unsaturated ethyl esters and alcohols

Stereoselective synthesis of (2S,3S,4Z)-4-fluoro-1,3-dihydroxy-2-(octadecanoylamino)octadec-4-ene, [(Z)-4-fluoroceramide], and its phase behavior at the air/water interface

“…It seems that the molecules of 4-fluoroceramide ( 2b ) interact more strongly with their hydrophobic parts due to the presence of fluorine, which might form intermolecular hydrogen bridges to the vinylic proton of the next molecule. Similar effects were observed in compressed monolayers of ethyl ( Z )-2-fluorooctadec-2-enoate [ 29 ] and ethyl (2 E ,4 Z )-4-fluorooctadeca-2,4-dienoate [ 43 ]. Moreover, a very short C–H···F–C distance (2.30 Å) was observed in crystalline state for ( Z )-2-amino-4-fluorododec-4-enecarboxylic acid [ 44 ].…”

“…Our synthetic sequence started from (ethoxycarbonylfluoromethyl)triphenylphosphonium bromide and tetradecanal, from which ( Z )-2-fluorohexadec-2-enal ( 3 ) was prepared in three steps according to a synthetic route we developed recently for the preparation of long chain α-fluoro-α,β-unsaturated carboxylic acid esters [ 29 ] and fluorinated 2,4-dienecarboxylic acid esters [ 30 ]. The key step of the synthesis is an asymmetric aldol reaction of the fluorinated aldehyde 3 with the enantiopure iminoglycinate 4 ( Scheme 1 ).…”

Stereoselective Synthesis of Fluorinated and Nonfluorinated Triazolo Analogues of Ceramides

“…5 On the other hand, due to their amphiphilic character, interesting properties are expected concerning the phase behavior at the air/water interface examined by film balance measurements. The monolayer formation of amphiphiles containing a second polar group, like fluorine or hydroxyl, within the alkyl chain led to an interesting phase behavior as described by our [7][8][9][10] and other groups. 11,12 Recently, we reported on the synthesis of enantiopure 4fluoroceramide and the influence of a single vinylic fluorine substituent on its phase behavior at the air/water interface.…”

Insights into the Headgroup and Chain Length Dependence of Surface Characteristics of Organic-Coated Sea Spray Aerosols

“…4,[28][29][30] In addition, fatty acid methyl esters are also known to be able to form organized structures at the air-water interface. [31][32][33][34] Previous studies of saturated long chain fatty acid and fatty acid methyl ester monolayers were carried out at the airwater interface with IRRAS technique, by which the conformational order of the monolayers were shown to be increased with increasing alkyl chain-length. [35][36] The response of SA and AA Langmuir monolayers to atmospheric inorganic ions was explored by Langmuir and IRRAS methods, which confirmed the existence of inorganic ions in the fatty acid monolayers and its impact on the surface properties of aqueous-phase aerosols.…”