Electrospray mass spectrometry (ESMS) of a series of europium(III) supramol
ecules derived from tris(2-aminoethyl)amine (tren) and 2,6-diformyl-4-R-phe
nol (R = F, Cl, t-Butyl) is described. The peaks were assigned by both m/Z
values and the isotope distributions. The ESMS are largely affected by the
nature of the cryptates.