Fragmentation of B12H11S-R(2−) in electrospray mass spectrometry

The electrospray ionization (ESI) mass spectrometry (MS) of (3-carboxyethyl)-thio-undecahydro-closo-dodecaborate(2−) shows the appearance of additional peaks corresponding to B12H11SH(2−) and B12H11(1−). Their origin can be traced to fragmentation reactions in the skimmer-CID region and the ion trap of the spectrometer.