Group dipole moments of fluoroalkyl substituents

4,6-Di-O-pentyl-3-O-trifluoroacetyl/propionyl cyclofructan stationary phases for gas chromatographic enantiomeric separations

“…The decrease in retention and selectivity could be the result of the amide hydrogen of the acetamide group being less acidic than the corresponding moiety in the trifluoroacetamide or pentafluoropropionic amide groups as well as the less pronounced dipole of the acetamide group as compared to the trifluoroacetamide or pentafluoropropionic amide groups. 42,43,46 Similar results were observed on the DP-PN-CF6 phase. Thus, fluoroalkylation reagents are preferred for the analyte derivatization when using these two cyclofructan based CSPs.…”

Molecular dynamics in semifluorinated‐side‐chain polysulfone studied by broadband dielectric spectroscopy

“…16% of μ CF due to the helical structure of the molecule25). The dipole moment of the CF 3 end group is given as 2.3 D 52, 53. From the Arrhenius fit, E A is found to be 38 ± 2 kJ/mol, which is within the range of local dipole fluctuations (i.e., E A < 50 kJ/mol) 42.…”

Chemistry, Physical Chemistry, and Uses of Molecular Fluorocarbon−Hydrocarbon Diblocks, Triblocks, and Related Compounds—Unique “Apolar” Components for Self-Assembled Colloid and Interface Engineering

“…154 While the existence of a substantial dipole moment for FnHm diblocks is unquestionable, the exact values of this moment and of its group contributions remain uncertain. The molecular dipole moment of CF 3 -CH 3 has been determined by microwave spectroscopy (hence as a dilute gas) to be 2.32 ( 0.03 D. 155 The following group dipole moments have been calculated for F-chains from experimental data obtained for the corresponding F-acid methyl esters FnCOOMe: CF 3 , 2.30 D; C 2 F 5 , 2.46 D; C 3 F 7 , 2.46 D; and C 4 F 9 , 2.47 D. 156 These values leveled off rapidly as the chain length increased.…”