DETECTION OF HYDROGEN-BONDED SUPRAMOLECULAR COMPLEXES USING ELECTROSPRAY-IONIZATION FROM CHLOROFORM

The stoichiometry of a noncovalent, hydrogen-bonded supramolecular com plex, hub(M)(3) . RCA(3), was characterized using electrospray ionizat ion from chloroform, The intact (1:3) complex was observed in the nega tive-ion mode as a Cl--bound species using Ph(4)Cl as the source of th e charge donor, Collisionally and thermally induced dissociation of th e (1:3) complex resulted in the simultaneous loss of all the three RCA units, indicating a cooperative binding of RCA units in the (1:3) com plex, These results suggest that the attachment of small, organic-solu ble ions may be a useful technique for mass spectrometric characteriza tion of neutral supramolecular complexes that are stable or soluble on ly in non-polar organic solvents.