Multiple cation binding by bola-amphiphilic crown ethers: Assessment by fast atom bombardment mass spectrometry

Bola-amphiphiles having two aza-18-crown4 ether rings attached by a covalent spacer (O-O) and an analogous tris(macrocycle) (O-O-O) have been prepared and their cation complexation behavior has been assessed by fast atom bombardment and collisionally activated dissociation tandem mass spectrometry; the key finding is that two cations may simultaneously be complexed by a two-or three-crown system and that this complexation may also involve an anion.