Cancer affects a major part of the worldwide population, and, to minimize deaths, the diagnosis in the early stages of the disease is fundamental. Thus, to improve diagnosis and treatment new potential spectroscopic probes are crucial. Benzothiazole derivates present antitumor properties and are highly selective and interact strongly with the enzyme phosphoinositide 3-kinase (PI3K), which was associated with cell proliferation and breast cancer cells. In this paper, the rhenium shielding tensors (187Re(σ)) and hydrogen and carbon chemical shifts (1H(δ) and 13C(δ)) of the Re(CO)3(NNO) complex conjugated with 2-(4'-aminophenyl)benzothiazole (ReABT) were evaluated. A statistical HCA model was used to analyze the best DFT protocol to compute σ and δ values and to evaluate the relativistic effects, both in the basis set and Hamiltonian as well as the functionals M06L or PBE0. The best protocol was applied to obtain 187Re(σ) of the ReABT complex in different environments (gas phase, solution, and in the active site of the PI3K enzyme). The results point out that 187Re(σ) values of the ReABT complex change significantly when the complex is docked in the PI3K enzyme.

• Klíčová slova
• DFT, HCA, RMN, ReCO3,
• MeSH
• benzothiazoly * MeSH
• fosfatidylinositol-3-kinasy * MeSH
• magnetická rezonanční spektroskopie MeSH
• rozpouštědla MeSH
• statistické modely MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• benzothiazoly * MeSH
• rozpouštědla MeSH

We have performed a hierarchical ab initio benchmark and DFT performance study of D2 Ch•••A- chalcogen bonds (Ch = S, Se; D, A = F, Cl). The ab initio benchmark study is based on a series of ZORA-relativistic quantum chemical methods [HF, MP2, CCSD, CCSD(T)], and all-electron relativistically contracted variants of Karlsruhe basis sets (ZORA-def2-SVP, ZORA-def2-TZVPP, ZORA-def2-QZVPP) with and without diffuse functions. The highest-level ZORA-CCSD(T)/ma-ZORA-def2-QZVPP counterpoise-corrected complexation energies (ΔECPC ) are converged within 1.1-3.4 kcal mol-1 and 1.5-3.1 kcal mol-1 with respect to the method and basis set, respectively. Next, we used the ZORA-CCSD(T)/ma-ZORA-def2-QZVPP (ΔECPC ) as reference data for analyzing the performance of 13 different ZORA-relativistic DFT approaches in combination with the Slater-type QZ4P basis set. We find that the three-best performing functionals are M06-2X, B3LYP, and M06, with mean absolute errors (MAE) of 4.1, 4.2, and 4.3 kcal mol-1 , respectively. The MAE for BLYP-D3(BJ) and PBE amount to 8.5 and 9.3 kcal mol-1 , respectively.

• Klíčová slova
• benchmark study, chalcogen bonds, coupled-cluster, density functional calculations, noncovalent interactions,
• Publikační typ
• časopisecké články MeSH

Static and dynamic magnetic properties of the tetracoordinate CoII complex [Co(CH3-im)2Cl2], (1, CH3-im = N-methyl-imidazole), studied using thorough analyses of magnetometry, and High-Frequency and -Field EPR (HFEPR) measurements, are reported. The study was supported by ab initio complete active space self-consistent field (CASSCF) calculations. It has been revealed that 1 possesses a large magnetic anisotropy with a large rhombicity (magnetometry: D = -13.5 cm-1, E/D = 0.33; HFEPR: D = -14.5(1) cm-1, E/D = 0.16(1)). These experimental results agree well with the theoretical calculations (D = -11.2 cm-1, E/D = 0.18). Furthermore, it has been revealed that 1 behaves as a field-induced single-ion magnet with a relatively large spin-reversal barrier (Ueff = 33.5 K). The influence of the Cl-Co-Cl angle on magnetic anisotropy parameters was evaluated using the CASSCF calculations.

• Klíčová slova
• slow‐relaxation of magnetization, magnetic  anisotropy, single ion magnet, tetracoordinate CoII,
• Publikační typ
• časopisecké články MeSH

Crystal structures and magnetic properties of polymeric and trinuclear heterobimetallic MnIII···PtII···MnIII coordination compounds, prepared from the Ba[Pt(CN)₄] and [Mn(L4A/B)(Cl)] (1a/b) precursor complexes, are reported. The polymeric complex [{Mn(L4A)}₂{μ⁴-Pt(CN)₄}]n (2a), where H₂L4A = N,N'-ethylene-bis(salicylideneiminate), comprises the {Mn(L4A)} moieties covalently connected through the [Pt(CN)₄]2- bridges, thus forming a square-grid polymeric structure with the hexacoordinate MnIII atoms. The trinuclear complex [{Mn(L4B)}₂{μ-Pt(CN)₄}] (2b), where H₂L4B = N,N'-benzene-bis(4-aminodiethylene-salicylideneiminate), consists of two [{Mn(L4B)} moieties, involving pentacoordinate MnIII atoms, bridged through the tetracyanidoplatinate (II) bridges to which they are coordinated in a trans fashion. Both complexes possess uniaxial type of magnetic anisotropy, with D (the axial parameter of zero-field splitting) = -3.7(1) in 2a and -2.2(1) cm-1 in 2b. Furthermore, the parameters of magnetic anisotropy 2a and 2b were also thoroughly studied by theoretical complete active space self-consistent field (CASSCF) methods, which revealed that the former is much more sensitive to the ligand field strength of the axial ligands.

• Klíčová slova
• crystal structures, magnetic anisotropy, manganese(III), platinum(II), zero-field splitting,
• MeSH
• komplexní sloučeniny chemie   MeSH
• krystalografie rentgenová MeSH
• ligandy MeSH
• magnetismus MeSH
• mangan chemie   MeSH
• molekulární struktura MeSH
• Schiffovy báze chemie   MeSH
• sloučeniny platiny chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• komplexní sloučeniny MeSH
• ligandy MeSH
• mangan MeSH
• Schiffovy báze MeSH
• sloučeniny platiny MeSH

The novel field-induced single-molecule magnet based on a tetracoordinate mononuclear heteroleptic Co(II) complex involving two heterocyclic benzimidazole (bzi) and two thiocyanido ligands, [Co(bzi)2(NSC)2], (CoL4), was prepared and thoroughly characterized. The analysis of AC susceptibility data resulted in the spin reversal energy barrier U = 14.7 cm(-1), which is in good agreement with theoretical prediction, U(theor). = 20.2 cm(-1), based on axial zero-field splitting parameter D = -10.1 cm(-1) fitted from DC magnetic data. Furthermore, mutual interactions between CoL4 and ferromagnetic barium ferrite BaFe12O19 (BaFeO) in hybrid materials resulted in suppressing of slow relaxation of magnetization in CoL4 for 1:2, 1:1 and 2:1 mass ratios of CoL4 and BaFeO despite the lack of strong magnetic interactions between two magnetic phases.

• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH