Incipient chemical bond formation of Xe to a cationic silicon cluster: Vibrational spectroscopy and structure of the Si4Xe+ complex

► The IR spectrum of Si4Xe+ is obtained using infrared multiple photon dissociation. ► Its spectrum differs from that predicted for bare Si4+, indicating a distinct influence of Xe. ► The interaction of Xe with Si4+ results in the formation of an incipient chemical Si-Xe bond.