Iterative Mass Spectrometry and X-Ray Crystallography to Study Ion-Trapping and Rearrangements by a Flexible Cluster

An important aspect of chemical reactions involves understanding the intermediate steps from reactants to products. The iterative use of mass spectrometry and X-Ray crystallography is demonstrated to be a powerful combination in this respect. We have applied them in identifying molecular clusters in solution followed by their solid-state structural characterizations. We used a key ligand, 2-[(2-hydroxy-3-methoxy-benzylidene)-amino]-ethanesulfonate (L), which serves as chelating/bridging units to stabilize the precursor [Li(4)Ni(6)(OH)(2)(L)(6)(CH(3)CN)(6)](ClO(4))(2)·4CH(3)CN. The results of subsequent reactions witness a cascade of processes involving fragmentation, inner bridging ligand substitution (OH(−) to OCH(3)(−)), changing modes of binding (chelate to monodentate) of the key ligand, ion-trapping and exchange (Li(+), Na(+) and Ca(2+)) and their site preferences, coordinating and non-coordinating solvents (CH(3)CN to CH(3)OH, H(2)O and EtOH) replacement. The flexibility of the Ni(3)OL(3) species in solution permits the formation of six derivatives. The complimentary techniques open a broader prospect for cluster design and applications.