High-resolution electrospray-ionization tandem-mass spectrometer

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Electrospray-ionization (ESI) mass spectrometry is one of the most powerful analytical methods for the identification of reactive and catalytic intermediates of chemical transformations. In particular, it is of great value for the analysis of organometallic species because it is able to distinguish between the different aggregation, association, and coordination states of the metal centers, even if fast dynamic equilibria occur in solution. Recent examples have also demonstrated that time-resolved ESI-mass spectrometric experiments can afford in-depth kinetic information. Finally, tandem-mass spectrometers offer the possibility to examine the microscopic unimolecular reactivity of mass-selected ions. In this way, individual elementary steps can be probed without the interference of intermolecular exchange processes or solvent coordination. The thus obtainable mechanistic insight is of key importance for the rational development of improved practical applications. The requested high-resolution ESI tandem-mass spectrometer will be used for determining the speciation of organocuprates and elucidating the mechanism of iron-catalyzed cross-coupling as well as transition-metal mediated fluorination and C–O activation reactions. Moreover, it will be applied to the real-time analysis of a wide range of polymerization reactions. At the same time, the tandem functionality of the requested instrument will be taken advantage of for examining transmetalation reactions and reductive eliminations for numerous transition-metal complexes. The applicant in charge has extensive experience in the use of high-resolution ESI tandem-mass spectrometers for mechanistic studies of organometallic reactions, most of which have been performed with an instrument commissioned in 2011. Due to the heavy wear resulting from the frequent infusion of highly concentrated sample solutions containing reactive organometallics into this device as well as due to the development of a new generation of mass spectrometers, the existing instrument no longer permits state-of-the-art experiments and needs to be replaced as soon as possible. The requested instrument will substitute the old one and, thus, ensure that the applicant and his collaboration partners can maintain their international competitiveness. Moreover, the superior mass resolution of the new instrument will offer exciting experimental possibilities far beyond those feasible with the old equipment.