Charge Density Studies of Thiathiophthene. 4 Theoretical Studies on 2,5‐Dimethyl Thiathiophthene and 2,4‐Diphenyl Thlathiophthene with Density Functional Method

Abstract

The distribution of deformation density of 2,5‐dimethyl thiathiophthene and 2,4‐diphenyl thiathiophthene are calculated via density functional method. The results are in good agreement with the corresponding experimental and theoretical distributions from an ab initio method. The ionization potentials obtained in this calculation on 2,5‐dimethyl thiathiophthene are in good agreement with those obtained experimentally from photoelectron spectroscopy, it is in better agreement than those VIPs based on ab initio calculations. Net atomic charges are compared with the experimental multipole refinement and with those calculated with ab initio and DFT methods for various atomic partitions.

Bond Characterization of Chromium−Fischer Carbene Complexes: A Combined Study of Experiment and Theory

“…It is obvious that values obtained in this work are far closer to the experimental ones than those from earlier calculations, and values from DFT are better than those from HF. However it needs to be pointed out that the values from DFT are calculated on the basis of the transition state. − If we plotted the calculated values with respect to the observed ones as a linear function, the slope in DFT values is often close to 1, as found elsewhere …”

“…[61][62][63] If we plotted the calculated values with respect to the observed ones as a linear function, the slope in DFT values is often close to 1, as found elsewhere. 95 One example on the first compound (XR′ ) NH 2 , R ) Ph) is such that the slopes are 1.00, 1.57, and 2.92 and the intercepts are 0.37, -3.60, and -13.50 respectively for DFT, ab initio/HF, and Fenske-Hall 5 calculations.…”

Bond Characterization of a Unique Thiathiophthene Derivative: Combined Charge Density Study and X-ray Absorption Spectroscopy

“…19 Because of such interesting bonding character, charge density studies have been applied to quite a few S-related compounds, [13][14][15]20,21 including the thiathiophthene (TTP) derivatives. 22−26 There are many TTP derivatives: some are symmetric with equal S−S bonds when the substituents are at the 2,5-positions; 23,25,26 others are asymmetric with a long and a short S−S bond when the substituents are at 2,4positions. 22,24−26 The title compound, 2,5-dimethyl-3,4-trimethylene-6a-TTP, belongs to a symmetric one.…”

“…Because of such interesting bonding character, charge density studies have been applied to quite a few S-related compounds, − ,, including the thiathiophthene (TTP) derivatives. − There are many TTP derivatives: some are symmetric with equal S–S bonds when the substituents are at the 2,5-positions; ,, others are asymmetric with a long and a short S–S bond when the substituents are at 2,4-positions. ,− The title compound, 2,5-dimethyl-3,4-trimethylene-6a-TTP, belongs to a symmetric one. It was indicated , that the Lewis resonance structures of TTP could be represented as in Figure , where the structure was described as a 10π electron aromatic system , plus a 3c-4e σ bond along S–S–S.…”

“…It was indicated , that the Lewis resonance structures of TTP could be represented as in Figure , where the structure was described as a 10π electron aromatic system , plus a 3c-4e σ bond along S–S–S. The deformation density of two TTP derivatives, one symmetric, 2,5-dimethyl-TTP, and the other asymmetric, 2,4-diphenyl-TTP, was investigated. − The S–S bond lengths of these compounds are all longer than the corresponding S–S single bond. The aim of this study is to establish the bond characterization on the title molecule through a combined experimental and theoretical charge density distribution as well as sulfur K-edge X-ray absorption spectroscopy (XAS).…”