Structure, conformational properties and matrix photochemistry of S -( tert -butyl)trifluorothioacetate CF 3 C(O)SC(CH 3 ) 3

CAYÓN, VANINA M.; ERBEN, MAURICIO F.; ROMANO, ROSANA M.; STAMMLER, HANS-GEORG; MITZEL, NORBERT W.; DELLA VÉDOVA, CARLOS O.

NEW JOURNAL OF CHEMISTRY

ROYAL SOC CHEMISTRY

Año: 2020 vol. 44 p. 14568 - 14577

1144-0546

S-(tert-Butyl) trifluorothioacetate, CF 3 C(O)SC(CH 3 ) 3 , was prepared by condensationof CF 3 C(O)Cl and (CH 3 ) 3 CSH under vacuum conditions. The compound was isolated andproperly characterized by using vibrational (infrared and Raman), UV-Vis and multinuclearNMR spectroscopy techniques and by mass spectrometry. The conformational preference andits crystal structure have been determined by means of FTIR spectroscopy (gas phase and Ar-matrix) and by X-ray diffraction. A charge density determination of X-ray diffraction (XRD)data of single crystals formed by in-situ crystallization reveals the presence of solely asynperiplanar conformation (syn form orientation of the C=O double bond with respect to theS?C single bond) belonging to the C S point group of symmetry. Intermolecular C=O···C=O andC=O···H?C interactions were detected in the crystal. Quantum-chemical calculations at theB3LYP/cc-pVTZ level of approximation reproduce the conformational preference and theexperimental geometrical parameters fairly well. Vibrational information was obtained from Ar-matrix isolation FTIR and liquid Raman spectroscopy. Additionally, CF 3 C(O)SC(CH 3 ) 3 isolatedin solid Ar at ca. 15 K was irradiated with and its photolysis products CF 3 SC(CH 3 ) 3 and COwere detected.