Photoisomerization of Matrix-Isolated Bis(trifluoromethyl) Sulfoxide:  Formation of the Sulfenic Ester CF₃SOCF₃

Abstract

Bis(trifluoromethyl) sulfoxide, CF(3)S(O)CF(3), isolated in noble gas matrixes at low temperatures, isomerizes upon UV irradiation into the sulfenic ester CF(3)SOCF(3). The new species is characterized spectroscopically, and the vibrational assignment is supported by (18)O isotopic labeling experiments and by DFT calculations. The calculated structural parameters of CF(3)SOCF(3) are compared with the calculated and experimental data of the related compounds CF(3)SSCF(3) and CF(3)OOCF(3). In addition, the computed enthalpy differences between the sulfoxide R(2)S=O and sulfenate RSOR structures for R = H, F, CH(3), and CF(3) are included.

Structural and Vibrational Properties of the CF3XXCF3 (X = O, S, Se, Te) Molecules

“…This mixed molecule was obtained by photolysis of CF 3 S(O)CF 3 isolated in an low temperature argon matrix 18. The optimized molecular structure obtained in the presented work predicted the following bond lengths: C–S = 1.835 Å, C–O = 1.375 Å, S–O = 1.706 Å, and a dihedral angle C–S–O–C = 103.2°.…”

“…The vibrational frequencies for the CF 3 SOCF 3 molecule were also calculated as a part of the presented work. The experimental values18 were reproduced with a RMSD of 13 cm –1 , but no further calculations were made.…”

Spectroscopic Characterization and Conformational Properties of S‐(Fluoroformyl)‐O‐(acetyl) Thioperoxide and S‐(Fluoroformyl)‐O‐(trifluoroacetyl) Thioperoxide

“…Moreover, thioperoxides CF 3 SOCF 3 [12] and CH 3 SOCH 3 [13] were observed and spectroscopically characterized in argon matrices after photoisomerization of CF 3 S(O)CF 3 and CH 3 S(O)CH 3 , respectively. The dihedral angle in CF 3 SOCF 3 [12] [φ(C-S-O-C) = 105°] is closer to that in the corresponding disulfide, CF 3 SSCF 3 [14] [φ(C-S- [11] [φ(C-S-O-C) = 100(4)°], CF 3 SOC(O)CF 3 [11] [φ(C-S-O-C) = 101(3)°], and CCl 3 SOC(O)CF 3 [16] [φ(C-S-O-C) = 108.5°].…”

“…The dihedral angle in CF 3 SOCF 3 [12] [φ(C-S-O-C) = 105°] is closer to that in the corresponding disulfide, CF 3 SSCF 3 [14] [φ(C-S- [11] [φ(C-S-O-C) = 100(4)°], CF 3 SOC(O)CF 3 [11] [φ(C-S-O-C) = 101(3)°], and CCl 3 SOC(O)CF 3 [16] [φ(C-S-O-C) = 108.5°]. Otherwise, in sulfenic esters with two C=O groups, the dihedral angle around the S-O bond is smaller than 90°, as in FC(O)-SOC(O)CF 3 [17] [φ(C-S-O-C) = 75(3)°] and CF 3 C(O)SOC-(O)CF 3 [18] [φ(C-S-O-C) = 77°].…”

“…Method HS-OH [34] 1.662 91.3 CCSD(T)/cc-pCVQZ CF 3 S-OCF 3 [12] 1.677 105.0 B3LYP/6-311++G(3df,3pd) CF 3 S-OC(O)CH 3 [11] 1.659 (4) 100(4) GED CF 3 S-OC(O)CF 3 [11] 1.663 (5) 101(3) GED CCl 3 S-OC(O)CH 3 [10] 1.663 (14) 105. . In the present study, we report the first example of a thioperoxide exhibiting two carbonyl substituents, FC(O) and CH 3 C(O), for which also a trans conformer (syn-trans-syn) with a contribution of 18 (5) % is observed.…”