Molecular Structure of M(N13) Compounds with 12-Membered Nitrogen-Containing Cycle and Axial Nitrogen Atom (M = Mn, Fe): Quantum-Chemical Design by DFT Method

Abstract

Based on the results of a quantum chemical calculation using the DFT method in the B3PW91/TZVP, OPBE/TZVP, M06/TZVP, and M062/Def2TZVP levels, the possibility of the existence of M(N13) chemical compounds (M = Mn, Fe) that are unknown for these elements has been predicted. Data on the structural parameters, the multiplicity of the ground state, APT and NBO analysis, and standard thermodynamic parameters of formation (standard enthalpy ΔfH0, entropy S0, and Gibbs’s energy ΔfG0) for these compounds are presented.

Coordination compounds with subporphyrazine may exist: DFT quantum chemical prediction for M(ii) complexes with a given macrocyclic ligand (M = Ti–Zn)

“…The calculations were carried out using the Gaussian09 program package. 48 As in our previous articles, in which the DFT method of calculation was used, 34–37 the correspondence of the found stationary points to the energy minima in all cases was proved by calculating the second derivatives of the energy to the coordinates of the atoms; herein, all equilibrium structures corresponding to the minimum points on the potential energy surfaces had only real (and, moreover, always positive) frequency values. Among the optimized structures for further consideration, the one with the lowest total energy was selected.…”

“…The version of the DFT method, namely, DFT with the B3PW91 functional described in detail in, [30][31][32] which combines the standard extended split valence basis set TZVP 33 and has already been used before by us, in particular, in, [34][35][36][37] was also used in this work. The use of the given version of the DFT method in this case is because according to, [30][31][32] it allows one to obtain the most accurate (i.e., close to experimental) values of the geometric parameters of molecular structures as well as much more accurate values of thermodynamic and other physicochemical parameters in comparison with other variants of the DFT method.…”

“…The version of the DFT method, namely, DFT with the B3PW91 functional described in detail in, 30–32 which combines the standard extended split valence basis set TZVP 33 and has already been used before by us, in particular, in, 34–37 was also used in this work. The use of the given version of the DFT method in this case is because according to, 30–32 it allows one to obtain the most accurate ( i.e.…”

First Examples of s-Metal Complexes with Subporphyrazine and Its Phenylene-Annulated Derivatives: DFT Calculations

“…The DFT/B3PW91 method [27][28][29] combined with the standard extended split valence basis set TZVP was successfully used in [30][31][32]. According to [27][28][29], the calculations at this theoretical level make it possible, as a rule, to obtain values of geometric structural parameters that are close to experimental values, as well as thermodynamic characteristics that are acceptable in accuracy compared to other variants of the DFT method.…”

“…This version of the DFT method, in principle, should provide more accurate data on the parameters of molecular and electronic structures than DFT B3PW91/TZVP; however, it is much more time consuming compared to it, and that is why we used it to compare the above data. Such a comparison was made by us in a recent article [32] using the example of Fe(VII) and Mn(VII) complexes with a 12-atomic (NNNN) tetradentate ligand and a nitride anion. The calculations were carried out using the Gaussian09 program package [35].…”