DFT Quantum-Chemical Modeling Molecular Structures of Cobalt Macrocyclic Complexes with Porphyrazine or Its Benzo-Derivatives and Two Oxygen Acido Ligands

Abstract

Based on the results of a quantum chemical calculation using the DFT method with the OPBE/TZVP and B3PW91/TZVP levels, the possibility of the existence of three cobalt heteroligand complexes containing in the inner coordination sphere porphyrazine, di[benzo]- and tetra[benzo]porphyrazine, and two oxygen (O2−) ions with probable oxidation state VI of Co, which is unknown for this element at the present time, was shown. Data on the structural parameters are presented. It was shown that CoN4 chelate nodes as well as all metal-chelate and non-chelate cycles in each of these complexes, were strictly planar. Besides, the bond angles formed by two donor nitrogen atoms and a Co atom were close or equal to 90°, while the bond angles formed by donor atoms N, Co, and O, in most cases, albeit insignificantly, differed from this value. Good agreement between the calculated data obtained using the above two versions of the DFT method was found. Standard thermodynamic parameters of formation (standard enthalpy ΔH0f, 298, entropy S0f, 298 and Gibbs’s energy ΔG0f, 298) for the indicated complexes were presented too.

Structural changes at complexing of 3d (4d) elements with “template” tetradentate ligand – 1,8-diimino-1,8-dimercapto- 3,6-diazaoctadien-3,5-dithione-2,7: DFT analysis

“…The calculations were performed by using the Gaussian09 program. 22 As in our earlier works, for example 10,11,23,24 the correspondence of the found stationary points to energy minima in all cases was proved by calculating the second derivatives of the energy to atomic coordinates; besides, all equilibrium structures corresponding to minimum points on the potential energy surfaces, had only positive values of frequencies. In the case of Cr(II) and Mo(II) complexes having 4d 4 electron configuration, multiplicities 1, 3, 5 and 7, in the case of Mn(II) and Tc(II) complexes (4d 5 ), 2, 4 and 6, for Fe(II) and Ru(II) ones (4d 6 ), 1, 3 and 5, for Co(II) and Rh(II) ones (4d 7 ), 2, 4 and 6, for Ni(II) and Pd(II) ones (4d 8 ), 1, 3 and 5, for Cu(II) and Ag(II) ones (4d 9 ), 2, 4 and 6, and for Zn(II) and Cd(II) ones (4d 10 ), 1 and 3, were considered.…”

A new chemical compound with an unusual ratio of number of carbon and nitrogen atoms – C(N12): quantum-chemical modelling

“…The calculations were carried out using the Gaussian09 program package. 43 As in our previous articles, in which this method of calculation was used, [40][41][42] 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; wherein, all equilibrium structures corresponding to the minimum points on the potential energy surfaces had only real (and, moreover, always positive) frequency values. Of the optimized structures for further consideration, the one with the lowest total energy was selected.…”

“…37-39 and used by us, in particular, in ref. [40][41][42]. The use of the B3PW91/TZVP method, in this case, is because, according to, 37-39 it allows one to obtain, as a rule, 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 physical-chemical parameters in comparison with other variants of the DFT method.…”

The Physical Chemistry and Chemical Physics (PCCP) Section of the International Journal of Molecular Sciences in Its Publications: The First 300 Thematic Articles in the First 3 Years

“…This direction is represented by 39 articles [ 28 , 35 , 129 , 134 , 136 , 190 , 191 , 192 , 193 , 194 , 195 , 196 , 197 , 198 , 199 , 200 , 201 , 202 , 203 , 204 , 205 , 206 , 207 , 208 , 209 , 210 , 211 , 212 , 213 , 214 , 215 , 216 , 217 , 218 , 219 , 220 , 221 , 222 , 223 ]. Their distribution, according to the above types, is presented in Table 7 .…”

“…In this research, the given reaction between cyclopentadiene and methyl acrylate was computationally investigated in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM] [PF 6 ], as a basis for the validation of the OPLS-VSIL to properly reproduce a reaction medium environment. The articles of group ( c ) include publications [ 28 , 129 , 136 , 193 , 195 , 199 , 200 , 202 , 208 , 209 , 212 , 213 , 215 , 220 ]: in most of them [ 129 , 136 , 195 , 199 , 200 , 202 , 208 , 209 , 212 , 215 ], the objects of quantum chemical calculations were the chelate and macrocyclic coordination compounds of various s -, p -, d -, and f -elements. The most significant of them seems to be publication [ 136 ], devoted to Pu(IV) and Pu(VI) complexes with tridentate (NNN)-donor-atomic ligands, in particular, di(pyridyl-2)amine, 1,3-diamino-2-azapropane, and 2,6-di(pyridyl-2) pyridine, the results of which can be very useful in the development of new extractants and organic sensors of plutonium.…”