| Abstract
| - The formation of the chlorosiloxane ring (Cl2SiO)2 from the reaction of SiCl4 with O2 has been studied usingdensity functional theory (DFT). Geometries of reactants, intermediates, transition states, and products werefully optimized, and the relative energies of the stationary points and all of the transition states were calculatedon the B3LYP/6-311G* level. The initial reaction of O2 with SiCl4 starts on the triplet surface with theinsertion of O2 in SiCl4. This will loosen one Cl atom, and a barrier of 56.6 kcal/mol must be overcome. Inthe next step Cl2 is eliminated and the cyclic-Cl2SiO2 is formed. The latter reacts with SiCl4, which involvesa barrier of 76.0 kcal/mol. This process leads to the formation of a low-lying intermediate Cl2SiO(OCl)SiCl3.The intermediate proceeds under elimination of Cl2 to the product (Cl2SiO)2 ring over a barrier of 71.3 kcal/mol. This study also shows that the formation of the Cl3SiO radical is found to be energetically more favorablethan that of Cl2SiO. This can lead to the growth of larger chlorosiloxanes.
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