- Highly regioselective rearrangement of 2,3-diaryl-oxiranes into 2,2-diarylacetaldehydes catalyzed by ytterbium porphyrin complex, Yb(TPP)OTf
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[5,10,15,20-Tetraphenylporphynato]ytterbium(III) triflate, Yb(TPP)-OTf, is an efficient Lewis acid catalyst for the highly regioselective rearrangement of 2,3-diaryloxiranes into 2,2-diarylacetaldehydes. The catalytic process can be easily performed not only in dichloroethane but also in a more environmentally friendly solvent, benzotrifluoride.
- Takanami, Toshikatsu,Nakajima, Shin-ichiro,Nakadai, Shoichi,Hino, Fumio,Suda, Kohji
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- Magnetocaloric behavior of REE porphyrin-based paramagnets at room temperature
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REE complexes with cyclic aromatic ligands are ranked as the molecular materials with both electronic functionality and a single-molecule magnet behavior at temperatures lower 80 K. At the temperature close to room, they display a positive magnetocaloric effect (MCE) often comparable with one in ferromagnetics. We were determined MCE during the magnetization of both (5,10,15,20-tetra(4-tert-butylphenylporphinato))ytterbium(III)chloride, (Cl)YbTtBuPP and (5,10,15,20-tetraphenylporphinato)ytterbium(III)chloride, (Cl)YbTPP in their aqueous suspensions over the temperature range of 278-320 K and in magnetic fields from zero to 1 T by the direct microcalorimetric method. Specific heat capacity in the solid of (Cl)YbTtBuPP/(Cl)YbTPP has been directly determined in zero magnetic fields using differential scanning calorimetry. Thermodynamic parameters of ytterbium(III) complexes magnetization namely enthalpy/entropy change was determined. To improve understanding of the correlation between (Cl)YbTtBuPP/(Cl)YbTPP magnetic properties and its electronic structure, we have compared magnetic behavior of paramagnets studied with those for (Cl)MTPP where M = Gd, Eu, Tm.
- Korolev,Lomova,Ramazanova,Balmasova,Mozhzhukhina
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