Characterization of self-assembled supramolecular [Ga4L6] host-guest complexes by electrospray ionization mass spectrometry.
Self-assembled supramolecular host-guest complexes have been characterized by electrospray ionization mass spectrometry. The spectra obtained by use of a Q-TOF instrument equipped with a Z-spray ion source show primarily the 3- and 4- charge states of the assemblies. The assemblies have the general formula [guest subset Ga4L6]11- where L represents the chelating bidentate catechol ligand 1,5-bis(2',3'-dihydroxy-benzamido)naphthalene and guests are tetramethyl ammonium (Me4N+), tetraethyl ammonium (Et4N+), tetra-n-propyl ammonium (Pr4N+) and decamethylcobaltocenium (Cp*2Co+) cations. For the first time, the mass spectrum of the empty assembly [Ga4L6]12- is reported. This article also reports that provided the electrospray ion source is capable of preserving noncovalent interactions, it is possible to observe host-guest complexes containing both weak binding guests as well as sterically demanding guests in the mass spectra. The present data suggest that electrospray mass spectrometry is a powerful tool for characterization of supramolecular host-guest complexes.
Andersen
Ulla N
UN
Department of Chemistry, University of California at Berkeley, Berkeley, California 94720-1460, USA.
Seeber
Georg
G
Fiedler
Dorothea
D
Raymond
Kenneth N
KN
Lin
Dayin
D
Harris
Don
D
D003460:Crystallization / Q000379:methods; D005708:Gallium / Q000032:analysis* / Q000737:chemistry*; D046911:Macromolecular Substances / Q000032:analysis* / Q000737:chemistry*; D008968:Molecular Conformation; D009281:Naphthalenes / Q000032:analysis* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D046911:Macromolecular Substances; D009281:Naphthalenes; C031721:naphthalene; D005708:Gallium