Opening of an icosahedral boron framework: A combined infrared spectroscopic and computational study

- We study the cage opening of the periodinated closo-dodecaborate B12I122− upon deiodination.
- We report infrared photodissociation spectra combined with electronic structure calculations.
- Quasi-icosahedral cage structures absorb exclusively below 975 cm−1.
- Breakup of the cage structure is signaled by IR activity above 1000 cm−1.
- Cage opening occurs in-between B12I8− and B12I7−.