AbstractThe concentration dependence of the1H and13C NMR chemical shifts in D2O and in CDCl3solutions were determined for (±)‐α‐phenylethylamine (I). Aqueous solutions of (−)‐Iand (+)‐I, 50% enantiomerically enriched in (−)‐ and (±)‐2, 2, 2,‐trifluoro‐1‐phenylethanol and the (+)‐ and (−)‐N‐formyl derivatives ofI, were also studied.1H nuclear Overhauser enhancements were used to check the conformations of the solutes at various concentrations and1HT1values were used to monitor the changes in molecular tumbling in solutions. The results are interpreted in terms of a spontaneous aggregation of solute molecules in water, with the possible determination of the critical micelle concentration. The time‐dependent splittings in the1H NMR spectra suggest further, more detailed, studies of the structures of the aggregates and the possibil