Photodissociation spectroscopy and dynamics of Si4

The photodissociation of Si4has been investigated using fast beam photofragment translational spectroscopy. The photofragment yield (PFY) spectrum shows features between 21370 and 22220 cm−1corresponding to the 1B1u←X̃1Agtransition that are attributed to multi-photon dissociation. Single-photon dissociation was examined at higher excitation energies ranging from 5.17 to 6.42 eV. The dominant product channel was found to be Si3+Si. Experimental photofragment translational energy distributions were modeled by phase space theory (PST), indicating statistical photodissociation with no exit barrier along the dissociation coordinate. PST modeling yields a dissociation energy of 4.60±0.15eVand ΔHf,00(Si4)=6.75±0.24eV.