Preparation and Properties of Trifluorothioacetic Acid- S-(trifluoromethyl)ester, CF ₃C(O)SCF ₃

Abstract

Trifluorothioacetic acid-S-(trifluoromethyl)ester, CF3C(O)SCF3, was prepared by reacting CF3C(O)Cl and AgSCF3 at 50 degrees C. The compound was characterized by (13)C-, (19)F-NMR, UV, and vibrational spectroscopy as well as by gas electron diffraction (GED) and quantum chemical calculations (HF, MP2, and B3LYP methods 6-31G(d) and 6-311+G(2df) basis sets). GED and vibrational spectroscopy result in the presence of a single conformer with C1 symmetry and synperiplanar orientation of the S-CF3 bond relative to the CO bond. This result is in agreement with quantum chemical calculations which predict the anti conformer to be higher in energy by about 4 kcal/mol. An assignment of the IR (gas) and Raman (liquid) spectra is proposed, and the GED analysis results in the following skeletal geometric parameters (r(a) and angle(a) values with 3sigma uncertainties; these parameters are thermal averages and are not inconsistent with calculated equilibrium values): C=O = 1.202(6) A, C-C = 1.525(10) A, S-C(sp(2)) = 1.774(3) A, S-C(sp(3)) = 1.824 (3) A. O=C-C = 118.7(21) degrees, O=C-S = 127.1(15) degrees, C-S-C = 99.8 (13) degrees.

Mixed bivalent transition metal complexes of 1,10-phenanthroline and 2-aminomethylthiophenyl-4-bromosalicylaldehyde Schiff base: Spectroscopic, molecular modeling and biological activities

“…All geometric parameters were allowed to relax and the global minimum structure has been identified by calculating the matrix of second derivative and ensures that all its Eigen values are positive. Natural bond order analysis has been carried out using NBO 3.0 program [37,38] as implemented in the G09W package.…”

Synthesis, DFT, computational exploration of chemical reactivity, molecular docking studies of novel formazan metal complexes and their biological applications

“…The molecular geometry for the studied compounds were fully optimized using Density functional theory B3LYP method, by implementing LANL2DZ basis set for Cu, Fe, Cr, Co and Ni‐atoms and 6–31 + G(d,p) basis set for the rest of atoms. No symmetry constrains were applied during the geometry optimization . NBO calculations have been performed at the same level of calculation by using NBO 3.1 program as implemented in the Gaussian 09 W software package.…”

“…No symmetry constrains were applied during the geometry optimization. [71,72] NBO calculations have been performed at the same level of calculation by using NBO 3.1 program as implemented in the Gaussian 09 W software package. The optimized structure was visualized using Chemcraft version 1.6 package [73] and GaussView version 5.0.9.…”

Substituent effects on the absorption and vibrational spectra of some 2-hydroxy Schiff bases: DFT/TDDFT, natural bond orbital and experimental study

“…NBO calculations have been performed at the B3LYP/6-311+G** level using the NBO 3.1 program as implemented in the Gaussian09W software package in order to quantitatively measure the intramolecular delocalization in the studied systems. NBO theory [35,36] proved to be extremely useful in analyzing hyper conjugative [37] interactions through the second-order perturbation energy (E (2) ), which is estimated as…”