The Equilibrium Structure of Silyl Fluoride

Abstract The experimental equilibrium structure of silyl fluoride has been determined using new sets of accurate rotational constants that have recently been obtained by taking into account the most important interactions between the excited vibrational states. The equilibrium structure has also been calculated at the CCSD(T) level of theory with the cc-pVQZ+1 basis set (including corrections for the core correlation). The anharmonic force field up to semidiagonal quartic terms has been calculated at the MP2 level of theory and the equilibrium structure has been derived from the experimental rotational constants and the ab initio rovibrational interaction parameters. Finally, the average structure of both 28 SiH 3 F and 28 SiD 3 F has been reevaluated and used to derive the equilibrium structure. These structures are compared and the experimental structure is found to be in slight disagreement with the other ones. The preferred structure is obtained by calculating the median value of the different structures. The results are r e (SiF)=1.5907 (9) A, r e (SiH)=1.4696 (13) A, ∠ e (HSiF)=108.32(15)°, and ∠ e (HSiH)=110.60(14)°.