Photodissociation spectroscopy and dynamics of Si4

The photodissociation of Si4 has been investigated using fast beam photofragment translational spectroscopy. The photofragment yield (PFY) spectrum shows features between 21 370 and 22 220 cm−1 corresponding to the 1B1u←X̃1Ag transition 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±0.15 eV and ΔHf,00(Si4)=6.75±0.24 eV.