Iterative mass spectrometry and X-ray crystallography to study ion-trapping and rearrangements by a flexible cluster

Abstract

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 CH3OH, H 2 O and EtOH) replacement. The flexibility of the Ni3 OL 3 species in solution permits the formation of six derivatives. The complimentary techniques open a broader prospect for cluster design and applications.