Aqua­(phthalocyaninato)magnesium n‐propyl­amine disolvate

The crystals of the title compound, [Mg(C₃₂H₁₆N₈)(H₂O)]·2C₃H₉N, are built up from MgPc(H₂O) [Pc is phthalo­cyaninate(2−)] and n‐propyl­amine mol­ecules that inter­act via O—H⋯N hydrogen bonds. The MgPc(H₂O) mol­ecule is non‐planar. The central Mg atom is coordinated by the four equatorial isoindole N atoms of the Pc ring system and by the O atom of an axial water mol­ecule. The Mg atom is displaced by 0.509 (1) Å from the N₄ plane towards the water O atom. MgPc(H₂O)·2(n‐propyl­amine) mol­ecules related by the inversion centre are linked by N—H⋯O hydrogen bonds to form a dimeric aggregate.     

Thermal properties of rare earth dodecaborides

We have measured heat capacity and thermal expansion of rare earth dodecaborides REB₁₂ (RE=Y, Tb-Tm, Lu). YB₁₂ and LuB₁₂ are diamagnetics whereas the other dodecaborides are ordered antiferromagnetically. The amplitude of the heat capacity discontinuity at the Néel temperature and the shape of the heat capacity variation in the critical region for all these antiferromagnetics are characteristics for amplitude-modulated magnetic structures. In the ordered state TbB₁₂ reveals two first-order phase transitions, most likely due to magnetic structure changes. The heat capacity of ErB₁₂ just below the Néel point shows an anomaly of unclear origin. From the Schottky contribution to the heat capacity we have determined crystal field parameters. They are completely different than that is estimated from Point Charge Model.     

Aqua(phthalocyaninato‐κ4N)magnesium(II) 3‐chloropyridine disolvate

The structure of the title compound, [Mg(C₃₂H₁₆N₈)(H₂O)]·2C₅H₄ClN, comprises MgPcH₂O [Pc is phthalocyaninate(2−)] and 3‐chloropyridine solvent molecules interacting via O—H...N hydrogen bonds and π–π interactions. The central Mg atom is (4+1)‐coordinated by four equatorial isoindole N atoms of the macrocycle and by the O atom of an axial water molecule. The MgPcH₂O molecule is not planar, the Mg atom being displaced by 0.496 (2) Å from the isoindole N₄ plane towards the water O atom. MgPcH₂O molecules related by a twofold screw axis interact via O—H...N_azamethine hydrogen bonds, forming a polymeric chain along the b axis, while those related by inversion centres form π–π interacting dimers.     

Barker–Larman Problem for Convex Polygons in the Hyperbolic Plane

We solve an analogue of the Barker–Larman problem for convex polygons in the hyperbolic plane.     

Crotonic,cynnamic, and propiolic acids motifs in the synthesis of thiopyrano[2,3-d][1,3]thiazoles via hetero-Diels–Alder reaction and related tandem processes

Various novel thiopyrano[2,3-d][1,3]thiazol-2-one-6-carboxylic acids derivatives were synthesized in 54–86% yields via hetero-Diels–Alder reactions and related acylation-based tandem processes of 5-arylidene-4-thioxo-2-thiazolidinones with crotonic, propiolic, and cynnamic acids derivatives. Stereo- and regioselectivity of cycloaddition were investigated.     

Anomalous High Temperature Structural Behavior of Potential Multifunctional Material SmCo0.5Cr0.5O3

Crystal structure parameters of the mixed cobaltite–chromite SmCo_0.5Cr_0.5O₃ in the temperature range of 298–1173 K were derived from in situ high-resolution X-ray synchrotron powder diffraction data. Similar to the parent SmCoO₃ compound, SmCo_0.5Cr_0.5O₃ reveals anomalous thermal expansion reflected in abnormal temperature dependence of the unit cell dimensions and the selected interatomic distances and angles. These anomalies are associated with temperature induced changes of spin state of Co³⁺ ions and coupled insulator-metal transition. Observed decreasing behavior of the bandwidth W points on the increasing population of the exited spin states of Co³⁺ ions in SmCo_0.5Cr_0.5O₃ with increasing temperature. First principle calculations revealed antiferromagnetic ground state of SmCo_0.5Cr_0.5O₃ as the most stable.     

Multifrequency electron paramagnetic resonance characterization of PpoA, a CYP450 fusion protein that catalyzes fatty acid dioxygenation

PpoA is a fungal dioxygenase that produces hydroxylated fatty acids involved in the regulation of the life cycle and secondary metabolism of Aspergillus nidulans . It was recently proposed that this novel enzyme employs two different heme domains to catalyze two separate reactions: within a heme peroxidase domain, linoleic acid is oxidized to (8R)-hydroperoxyoctadecadienoic acid [(8R)-HPODE]; in the second reaction step (8R)-HPODE is isomerized within a P450 heme thiolate domain to 5,8-dihydroxyoctadecadienoic acid. In the present study, pulsed EPR methods were applied to find spectroscopic evidence for the reaction mechanism, thought to involve paramagnetic intermediates. We observe EPR resonances of two distinct heme centers with g-values typical for Fe(III) S = (5)/(2) high-spin (HS) and Fe(III) S = (1)/(2) low-spin (LS) hemes. (14)N ENDOR spectroscopy on the S = (5)/(2) signal reveals resonances consistent with an axial histidine ligation. Reaction of PpoA with the substrate leads to the formation of an amino acid radical on the early millisecond time scale concomitant to a substantial reduction of the S = (5)/(2) heme signal. High-frequency EPR (95- and 180-GHz) unambiguously identifies the new radical as a tyrosyl, based on g-values and hyperfine couplings from spectral simulations. The radical displays enhanced T(1)-spin-lattice relaxation due to the proximity of the heme centers. Further, EPR distance measurements revealed that the radical is distributed among the monomeric subunits of the tetrameric enzyme at a distance of approximately 5 nm. The identification of three active paramagnetic centers involved in the reaction of PpoA supports the previously proposed reaction mechanism based on radical chemistry.     

Reactions of ((i)PrO)3M≡M(O(i)Pr)3 (M = Mo, W) with low-coordinate phosphorus compounds. Formation of the first four-membered planar metallacycles, containing an M≡M triple bond

The low-coordinate phosphorus compounds (Me(3)Si)(2)N-P=NSiMe(3), (Me(3)Si)(2)N-P(=S)=N(t)Bu and (Me(3)Si)(2)N-P(=NSiMe(3))(2) react with ((i)PrO)(3)M≡M(O(i)Pr)(3) (M = Mo, W) to form four- and five-membered metallacycles with intact endocyclic or exocyclic M≡M triple bonds. The first four-membered planar metallacycles, containing an M≡M triple bond were obtained in reaction with (Me(3)Si)(2)N-P=NSiMe(3).     

Characterization of solutions of a class of ultraparabolic equations of the Kolmogorov type

For a class of ultraparabolic equations of the Kolmogorov type, we prove the theorems on the correct solvability and the integral representation of solutions of the Cauchy problem, whose initial data belong to special weight spaces of functions and generalized Borel measures. On the basis of these theorems, we obtained the full characterization of appropriate classes of solutions of the equations under consideration.