Gas-phase structure, rotational barrier and vibrational properties of trimethylsilyl trifluoroacetate CF3C(O)OSi(CH3)3: An experimental and computational study

M. E. DEFONSI LESTARD; M. E. TUTTOLOMONDO; E. L. VARETTI; D. A. WANN; H. E. ROBERTSON; D. W- H. RANKIN; A. BEN ALTABEF

JOURNAL OF MOLECULAR STRUCTURE

ELSEVIER SCIENCE BV

Año: 2010 vol. 978 p. 114 - 123

0022-2860

The molecular structure of trimethylsilyl trifluoroacetate, CF3C(O)OSi(CH3)3, has been determined in the gas phase from electron-diffraction data supplemented by ab initio (MP2) and DFT calculations using 6- 31G(d), 6-311G(d,p), 6-311++G(d,p) and 6-311++G(3df,3pd) basis sets. Experimental data indicate that only one conformer, with Cs symmetry [dihedral angle /(CCOSi) = 180, and all groups staggered], is observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered 31G(d), 6-311G(d,p), 6-311++G(d,p) and 6-311++G(3df,3pd) basis sets. Experimental data indicate that only one conformer, with Cs symmetry [dihedral angle /(CCOSi) = 180, and all groups staggered], is observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered 31G(d), 6-311G(d,p), 6-311++G(d,p) and 6-311++G(3df,3pd) basis sets. Experimental data indicate that only one conformer, with Cs symmetry [dihedral angle /(CCOSi) = 180, and all groups staggered], is observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered observed in the gas phase. Theoretical data indicate that both this anti conformer and a gauche conformer, created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggered created by rotating about the C(O)AO bond, are possible, although the preferred conformation is the staggere