19F, 13C NMR analysis of an oxygen carrier,perfluorotributylamine, and perfluoropentanoic acid

NMR relaxation measurement of perfluorocarbons (PFCs), such as perfluorotributylamine (FTBA), is a convenient method for the determination of oxygen concentrations in tissues and tumors. Previous relaxation studies of FTBA used different ¹⁹F NMR assignments causing some confusion. Fluorine‐detected ¹⁹F, ¹³C HMQC and HMBC and selectively ¹⁹F‐decoupled ¹³C NMR provided unequivocal ¹⁹F and ¹³C assignments for FTBA and perfluoropentanoic acid (FPA). Based on those assignments, ¹³C spin–lattice relaxation time constants (T₁) and effective correlation times for FTBA and FPA are reported and discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

Thermodynamics of solutions of iodine and perfluorocarbons in cycloalkanes

The solubilities of iodine from 9 to 30°C were measured in the C₅, C₆, C₇, C₈, and C₁₀ cycloalkanes. The solubilities were found to increase smoothly with ring size and to be greater than these of corresponding n-alkane. The results are analyzed in terms of the solubility parameter version of the regular solution theory and, unlike the n-alkanes, good agreement is found suggesting that the cycloalkanes are good model substances for testing theoretical predictions of the effect of molecular size on the thermodynamics of liquid mixtures and that molecular shape and flexibility need not be considered, at least in equilibrium properties governed by the free energy. A similar analysis of the upper critical solution temperatures of cyloalkane + perfluorotributylamine, cycloalkane + perfluorocyclohexane, and n-alkane + perfluorotributylamine mixtures leads to the same conclusion.