Vol 482, No 1 (2018)

The structure, energies, and magnetic properties of electromeric forms of binuclear Fe–M complexes (M = Co, Ni, Cu, Zn) with a 1,10-phenanthroline-based linker have been studied by the DFT UB3LYP*/6-311++G(d,p) method. Studying the spin-state switching mechanisms has demonstrated that all the compounds under consideration are capable of undergoing spin crossover at the iron ion. In solutions of complexes with cobalt and nickel bis-chelates, a competing process accompanied by the change in magnetic characteristics—configurational isomerism—is possible.

Activation barriers for fast 1,3-N,N' migrations of phenylmercury groups in the corresponding derivatives of N,N'-di(p-tolyl)form(benz)amidines have been calculated by density functional theory B3LYP/Gen, 6-311++G(d,p)/SDD to be ΔE_ZPE^≠= 4.5 and 3.0 kcal/mol. The results correspond to the data of dynamic NMR, which have shown the upper limit of activation barriers of these rearrangements (ΔG^≠) to be below 8 kcal/mol. The calculations have shown that the most stable is the E-syn form of N-phenylmercury-N,N'-di(p-tolyl)form(benz)amidines stabilized by supplementary intramolecular coordination of mercury atom with imine nitrogen atom of the amidine triad.

Two new fused quinoxaline-containing monomers—2,3-bis(9-(2-decyltetradecyl)-9H-carbazol-3-yl)dithieno[3,2-f:2'3'-h]quinoxaline (М1) and 2,5-di(nonadecan-3-yl)bis[1,3]thiazolo[4,5-a:5',4'-c]bisthieno[3,2-h:2',3'-j]phenazine (М2)—have been synthesized in high yields of 88 and 83% as promising building blocks of D-A polymers for photovoltaic applications. The optical bandgaps, found from the absorption edge, are 2.79 and 2.88 eV, respectively. The HOMO/LUMO energies of М1 and М2 are–5.83/–2.96 and–5.83/–2.98 eV, respectively. Both monomers have low-lying HOMO levels, which is favorable for a high open-circuit voltage and a high stability in air in the development of PSCs. The E_g^ec values of monomers М1 and М2 are 2.87 and 2.85 eV and are consistent well with the optical bandgap (2.79 and 2.88 eV, respectively).

Titanium-based alloy with low-toxic metals such as niobium, tantalum and zirconium (TiNbTaZr) was manufactured. The primary weight percentages of elements used for fusion were: titanium, 65%; niobium, 20%, tantalum, 10%; and zirconium, 5%. The TiNbTaZr alloy had a yield strength of about 550 MPa, a tensile strength of about 700 MPa, and a Young’s modulus of about 50 GPa, that is, it was comparable with Nitinol. A primary study of the biocompatibility of the TiNbTaZr alloy using the SH-SY5Y cells showed that the alloy did not have significant short-term toxicicity towards the cells incubated on the alloy surface. The number of non-viable cells was 2.5 times lower on the TiNbTaZr alloy than on Nitinol. The biocompatibility of TiNbTaZr was more pronounced than that of the Nitinol reference sample.