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Abstract

Perhalogenated closo-dodecaborates [B₁₂X₁₂]^2- (X = F, Cl, Br, I) play a key role in room temperature ionic liquids, electrolytes for lithium ion batteries, and stabilization of multiply charged cations. The central goal of this master thesis is to spectroscopically test predicted changes in the structure of the B₁₂-icosahedron, found in the periodinated closo-dodecaborate [B₁₂I₁₂]^2- upon partially deiodination. To this end, infrared photodissociation (IR-PD) spectra are measured using an ion-trap triple mass spectrometer. In order to simplify the acquisition of the IR-PD spectra, a genetic algorithm is implemented to automate the optimization of the ion optics, because manual optimization of these voltages, in particular for the ion-trap, is typically very tedious and time-consuming. [B₁₂I₁₂]^2- clusters are brought into the gas phase by electrospray ionization, and the singly-charged fragment ions [B₁₂I_n]^- (n = 5-11) are produced by collisioninduced dissociation. The IR-PD spectra of [B₁₂I₁₂]^2- and [B₁₂I_n]^- (n = 7-9) are assigned on the basis of electronic structure calculations and provide unambiguous evidence that cage-opening occurs in between n = 8 and n = 7.