Data for unwrapping a dodecaboranes’ B12 core: A structure, electronic property, and chemical reactivity study over the holistic series of [B12In]– (n = 11–1)

Successively stripping the exohedral substituents from the stable closo-dodecaborate anion [B12I12]2– results in structural transformations of the icosahedral B12 into a (quasi-)planar unsubstituted B120/– unit. Previous studies have finally pinpointed the first ions with an open B12 unit to [B12I7]–, but further transitions in geometry, electronic structure and chemical reactivity across the whole range of fragments [B12In]– (n = 11–1) remained elusive. Herein, we report a systematic investigation to explore the chemical properties of these intermediate structures using negative ion photoelectron spectroscopy (NIPES), ion mobility spectrometry (IMS), ion-molecule reactions, and quantum chemical calculations. [B12In]– ions can be categorized into three groups: (1) very reactive fragments with intact (quasi-)icosahedral B12-cages (n = 11–8), (2) less reactive open structures (n = 7–4), and (3) almost unreactive (quasi-)planar structures (n = 3–1). Preparative mass spectrometry shows that the unsaturated B12 core of category (2) ions tends to form smaller fully substituted closo-borate anions [BmXm]2– (m=6-11 with X=I, H, OH) on surfaces. In contrast, category (3) ions fully decay, and no ions were found on surfaces. This research provides fundamental insights into physical and chemical properties of B12 units depending on their substitution level and paves the way for the rational design of boron-rich compounds using unconventional [B12In]– building blocks. The raw data was collected on a Thermo linear quadrupole ion trap mass spectrometer and the files are named in the following order: mode of ionization, ionization source, name of the neutral reagent, targeted ion of interest and the isolation steps.