Measurement of gas‐phase binding energies of crown ethers with metal ions by Fourier‐transform ion cyclotron resonance mass spectrometry

Complexes of the type [crown+M] + were observed following laser desorption ionization of 18‐crown‐6 molecules ‘doped’ with K + , Cs + , and Ba + . Laser desorption ionization of 15‐crown‐5 and 12‐crown‐4 ‘doped’ with the same metals gave [(crown)] 2 +[M] + type sandwich complexes. Binding energies of crown ethers with different metal ions in all such complexes have been estimated from appearance energies obtained in the collisionally‐activated dissociation of the corresponding laster desorbed complexes.