Density functional theory calculated data of the iodomethane oxidative addition to oligothiophene-containing rhodium complexes – Importance of dispersion correction

Electronic and free energy data of density functional theory calculated optimized geometries of the reactants, transition state of the oxidative addition reaction and different reaction products of the [Rh(RCOCHCOCF3)(CO)(PPh3)] + CH3I reactions (R = C4H3S, C4H3S-C4H2S and C4H3S-C4H2S-C4H2S) are presented to illustrate the influence of the amount of thiophene groups, the implicit solvent and dispersion correction on the calculated energies. All calculations were done with the B3LYP functional, in gas as well as in solvent phase, with and without dispersion correction. The data can save computational chemists time when choosing an appropriate method to calculate reaction energies of oxidative addition reactions. Detailed knowledge of energies involved in the oxidative addition reaction of methyl iodide to rhodium complexes have an important implication in catalysis, for example the Monsanto process where methanol is converted to acetic acid catalysed by a rhodium complex. For more insight in the reported data, see the related research article “Synthesis, characterization, electrochemistry, DFT and kinetic study of the oligothiophene-containing complex [Rh((C4H3S-C4H2S)COCHCOCF3)(CO)(PPh3)]”, published in Polyhedron [1].

© 2021 The Author(s

Value of the Data
• Free energy data involved in oxidative addition reactions are important in the field of catalysis such as the oxidative addition reaction involved in the manufacturing of methanol from acetic acid (Monsanto process). • Free energy data obtained by different computational chemistry approaches, namely in gas and solvent phase, with and without dispersion corrections helps computational chemistry researchers in the choice of method when calculating energies involved in oxidative addition reactions. • Free energy data obtained by different computational chemistry approaches, indicates which method gives energies in agreement with experiment, making the theoretical prediction of energies involved in related oxidation addition reactions possible.

Data Description
Electronic and free energy data of the reactants, first transition state (TS) and the possible reaction products of [Rh(RCOCHCOCF 3 )(CO)(PPh 3 )] + CH 3 I reaction (R = C 4 H 3 S (tta) [2] , C 4 H 3 S-C 4 H 2 S (di-tta) [1] and C 4 H 3 S-C 4 H 2 S-C 4 H 2 S (tri-tta)) shown in Scheme 1 , are specified in the graphs in Figs. 1 -5 . The influence of dispersion correction to the energy data of the Rh(I)-di-tta + CH 3 I reaction (R = C 4 H 3 S-C 4 H 2 S) is illustrated in Fig. 1 (gas phase data), Fig. 2 (data in chloroform as solvent) and Fig. 3 (data in methanol as solvent). The influence of the phase (gas, chloroform or methanol) to the energy data of the Rh(I)-di-tta + CH 3 I reaction (R = C 4 H 3 S-C 4 H 2 S) is illustrated in Fig. 4 (B3LYP-D3 data). The influence of the amount of thienyl groups to the energy data of the Rh(I) + CH 3 I reaction (R = C 4 H 3 S (tta), C 4 H 3 S-C 4 H 2 S (di-tta) and C 4 H 3 S-C 4 H 2 S-C 4 H 2 S (tri-tta)) is illustrated in Fig. 5 (B3LYP-D3 data in chloroform as

Experimental Design, Materials and Methods
Density functional theory (DFT) calculations using the Gaussian 16 package [6] , were used to determine the optimized geometry and energy of the spesified molecules. The input coordinates for the compounds were constructed using Chemcraft [7] . The coordinates were spesified in the input files of the DFT calculations. DFT calculations were performed using the hybrid functional B3LYP functional [8,9] applying the GTO (Gaussian type orbital) triple-ζ basis set 6-311G(d,p) for the lighter atoms (C, H, O, F) and the Lanl2dz basis set [10] , that corresponds to the Los Alamos ECP plus DZ, for Rh and I. The optimization is performed using Berny algorithm using GEDIIS [11] as implemented in Gaussian 16. The convergence is reached when the root mean square force, the maximum force, the root mean square displacement and the maximum displacement are within the threshold of 0.0 0 030, 0.0 0 045, 0.0 012 and 0.0 018 atomic units, respectively. The requested convergence on energy is 1.0D-8 atomic unit. Calculations were done with and without Grimme's D3 dispersion correction [12] , in gas and solvent phase, using either chloroform or methanol as solvent. For solvent calculations, the integral equation formalism polarizable continuum model (IEFPCM) of solvation to describe the dielectric continuum medium, was used [13 , 14] . Frequency calculations were done on all molecules to ensure true minimum energy (no imaginary frequency) or transtion state structure (one imaginary frequency), and to provide the free energies of the molcules. The free energies were obtained from the output files searching for "Sum of electronic and thermal Free Energies = ". The electronic energies were obtained from the output files at the final optimization step, searching for "SCF Done" from the bottom of the output file.    Table 1 Electronic (E (eV)) and free energy (G (eV)) data of the indicated reaction products of the [Rh(RCOCHCOCF 3 )(CO)(PPh 3 )] + CH 3 I (MeI), reaction (R = C 4 H 3 S (tta), C 4 H 3 S-C 4 H 2 S (di-tta) and C 4 H 3 S-C 4 H 2 S-C 4 H 2 S (tri-tta)) calculated with B3LYP (with and without dispersion correction) and the indicated phase (gas, chloroform or methanol).

Ethics Statement
This work does not require any ethical statement.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships which have or could be perceived to have influenced the work reported in this article.