Vacuum

Example 1

InCl (1 eq.) was added to a Schlenk flask charged with LiCp(CH₂)₃NMe₂ (11 mmol) in Et₂O (50 mL). The reaction mixture was stirred overnight at room temperature. After filtration of the reaction mixture, the solvent was evaporated under reduced pressure to obtain a red oil. After distillation a yellow liquid final product was collected (mp˜5° C.). Various measurements were done to the final product. ¹H NMR (C₆D₆, 400 MHz): δ 5.94 (t, 2H, Cp-H), 5.82 (t, 2H, Cp-H), 2.52 (t, 2H, N—CH₂—), 2.21 (t, 2H, Cp-CH₂—), 2.09 (s, 6H, N(CH₃)₂, 1.68 (q, 2H, C—CH₂—C). Thermogravimetric (TG) measurement was carried out under the following measurement conditions: sample weight: 22.35 mg, atmosphere: N₂ at 1 atm, and rate of temperature increase: 10.0° C./min. 97.2% of the compound mass had evaporated up to 250° C. (Residue <2.8%). T (50%)=208° C. Vacuum TG measurement was carried out under delivery conditions, under the following measurement conditions: sample weight: 5.46 mg, atmosphere: N₂ at 20 mbar, and rate of temperature increase: 10.0° C./min. TG measurement was carried out under delivery conditions into the reactor (about 20 mbar). 50% of the sample mass is evaporated at 111° C.

Using In(Cp(CH₂)₃NMe₂) synthesized in Example 1 as an indium precursor and H₂O and O₃ as reaction gases, indium oxide film may be formed on a substrate by ALD method under the following deposition conditions. First step, a cylinder filled with In(Cp(CH₂)₃NMe₂) is heated to 90° C., bubbled with 100 sccm of N₂ gas and the In(Cp(CH₂)₃NMe₂) is introduced into a reaction chamber (pulse A). Next step, O₃ generated by an ozone generator is supplied with 50 sccm of N₂ gas and introduced into the reaction chamber (pulse B). Following each step, a 4 second purge step using 200 sccm of N₂ as a purge gas was performed to the reaction chamber. 200 cycles were performed on a Si substrate having a substrate temperature of 150° C. in the reaction chamber at a pressure of about 1 torr. As a result, an indium oxide film will be obtained at approximately 150° C.

Example 2

Same procedure as Example 1 started from Li(CpPiPr₂) was performed to synthesize In(CpPiPr₂). An orange liquid was obtained. ¹H NMR (C₆D₆, 400 MHz): δ 6.17 (t, 2H, Cp-H), 5.99 (t, 2H, Cp-H), 1.91 (sept, 2H, P—CH—), 1.20-1.00 (m, 12H, C—CH₃).

Using In(CpPiPr₂) synthesized in Example 2 as the indium precursor and H₂O and O₃ as the reaction gases, indium oxide film may be formed on a substrate by the ALD method under the following deposition conditions. First step, a cylinder filled with In(CpPiPr₂) is heated to 90° C., bubbled with 100 sccm of N₂ gas and the In(CpPiPr₂) is introduced into a reaction chamber (pulse A). Next step, O₃ generated by an ozone generator is supplied with 50 sccm of N₂ gas and introduced into the reaction chamber (pulse B). Following each step, a 4 second purge step using 200 sccm of N₂ as a purge gas was performed to the reaction chamber. 200 cycles were performed on the Si substrate having a substrate temperature of 150° C. in an ALD chamber at a pressure of about 1 torr. As a result, an indium oxide was obtained at 150° C.

Example 1

10 g (33.09 mmol) of 1-(2-fluoro-6-trifluoromethyl-benzyl)-6-methyl-1H-pyrimidine-2,4-dione (III), 6.8 g (49.62 mmol) of K₂CO₃ and 2.4 g (6.6 mmol) of tetrabutylammonium iodide were mixed with 50 mL of acetone at the temperature of about 20° C. Subsequently, 13.6 g (43.12 mmol) of (R)-2-((tert-butoxycarbonyl)amino)-2-phenylethyl methanesulfonate (IVa) were added and the obtained mixture was heated at the temperature of about 55° C. and maintained under stirring for about 16 hours at said temperature.

Once this maintenance was finished, the solvent was vacuum distilled and 50 mL of ethyl acetate and 50 mL of water were added to the residue thus obtained. A 1 M aqueous solution of HCl was slowly added, maintaining the temperature between 20 and 25° C. until achieving a pH of between 7 and 8. The aqueous phase was separated and treated with 3 fractions of 30 mL each of ethyl acetate. All the organic extracts were pooled and the solvent was removed by means of vacuum to obtain a slightly yellowish oily residue to which 45 mL of methanol were added, obtaining complete dissolution of the residue.

Example 2

16.1 g (99.24 mmol) of iodine monochloride (ICI) were dissolved in 40 mL of methanol at the temperature of about 10° C. The methanol solution previously obtained according to the methodology described in Example 1 comprising 3-((R)-2-(tert-butoxycarbonyl)amino-2-phenylethyl)-1-(2-fluoro-6-trifluoromethylbenzyl)-6-methyl-1H-pyrimidine-2,4-dione (II) was added to the iodine monochloride solution, maintaining the temperature between 20 and 25° C. Once the addition was finished, the obtained solution was heated to about 50° C. and was maintained under stirring for 2 hours at the mentioned temperature.

Once the maintenance was finished, the solvent was vacuum distilled and 50 mL of acetone were slowly added to the obtained oily residue at the temperature of between and 25° C. The addition of acetone caused a solid precipitate to appear almost immediately. The obtained mixture was maintained for 1 hour under stirring at the mentioned temperature. The resulting solid was isolated by filtration, washed with two fractions of 25 mL of acetone, and finally dried at the temperature of 50° C. to obtain 15.6 g (80.8% yield) of a white solid corresponding to the 3-((R)-2-(amino-2-phenylethyl)-1-(2-fluoro-6-trifluoromethylbenzyl)-5-iodo-6-methyl-1H-pyrimidine-2,4-dione hydrochloride salt (Ia) (UHPLC purity: 98.9%).

¹H-NMR (d₆-DMSO, 400 MHz) δ (ppm): 8.70 (2H, s broad), 7.65-7.48 (3H, m), 7.40-7.32 (5H, m), 5.40-5.29 (2H, dd), 4.47 (1H, t), 4.25 (2H, dd), 2.65 (3H, s).

¹³C-NMR (d₆-DMSO, 100 MHz) δ (ppm): 161.87, 159.47, 159.41, 154.19, 150.98, 134.70, 129.93, 129.84, 129.01, 128.58, 127.38, 122.61, 122.34, 122.22, 121.34, 121.10, 74.80, 52.26, 45.45, 44.60, 25.66.

The DSC of this compound is shown in FIG. 1 and the XRPD is shown in FIG. 2.

Example 1

95 g of manganese (purity: 99.95%; purchased from Taewon Scientific Co., Ltd.) and 5 g of high-purity graphite (purity: 99.5%; purchased from Taewon Scientific Co., Ltd.) were placed in a water-cooled copper crucible of an argon plasma arc melting apparatus (manufactured by Labold AG, Germany, Model: vacuum arc melting furnace Model LK6/45), and melted at 2,000 K under an argon atmosphere. The melt was cooled to room temperature at a cooling rate of 10⁴ K/min to obtain an alloy ingot. The alloy ingot was crushed to a particle size of 1 mm or less by hand grinding. Thereafter, the obtained powders were magnetically separated using a Nd-based magnet to remove impurities repeatedly, and the Mn₄C magnetic powders were collected. The collected Mn₄C magnetic powders were subjected to X-ray diffraction (XRD) analysis (measurement system: D/MAX-2500 V/PO, Rigaku; measurement condition: Cu—K_α ray) and energy-dispersive X-ray spectroscopy (EDS) using FE-SEM (Field Emission Scanning Electron Microscope, MIRA3 LM).

FIGS. 2(a) and 2 (b) show an X-ray diffraction pattern and an energy-dispersive X-ray spectroscopy graph of the Mn₄C magnetic material produced according to Example 1 of the present disclosure, respectively.

As can be seen in FIG. 2(a), the Mn₄C magnetic material showed diffraction peaks of (111), (200), (220), (311) and (222) crystal planes at 2θ values of 40°, 48°, 69°, 82° and 88°, respectively, in the XRD analysis. Thus, it can be seen that the XRD patterns of the Mn₄C magnetic material produced according to Example 1 are well consistent with the patterns of the cubic perovskite Mn₄C. In addition, the Mn₄C magnetic material shows several very weak diffraction peaks that can correspond to Mn₂₃C₆ and Mn. That is, the diffraction peak intensity at 2θ values of 43° and 44°, which correspond to Mn and Mn₂₃C₆ impurities, is as very low as about 2.5% of the diffraction intensity of the peak corresponding to the (111) plane. Through this, it can be seen that the powders obtained in Example 1 have high-purity Mn₄C phase. The lattice parameter of the Mn₄C is estimated to be about 3.8682 Å.

FIG. 2(b) shows the results of analyzing the atomic ratio of Mn:C in the powder by EDS. The atomic ratio of Mn:C is 80.62:19.38, which is very close to 4:1 within the experimental uncertainties. Thus, it can be seen that the powder is also confirmed to be Mn₄C.

The M-T curve of the field aligned Mn₄C powder obtained in Example 1 was measured under an applied field of 4 T and at a temperature ranging from 50 K to 400 K. Meanwhile, the M-T curve of the randomly oriented Mn₄C powder was measured under an applied field of 1 T. The Curie temperature of Mn₄C was measured under 10 mT while decreasing temperature from 930 K at a rate of 20 K/min.

FIGS. 3(a) to 3(c) show the M-T curves of the Mn₄C magnetic material, produced according to Example 1 of the present disclosure, under magnetic fields of 4 T, 1 T, and 10 mT, respectively.

FIG. 3 shows magnetization-temperature (M-T) curves indicating the results of measuring the temperature-dependent magnetization intensity of the Mn₄C magnetic material, produced in Example 1, using the vibrating sample magnetometer (VSM) mode of Physical Property Measurement System (PPMS®) (Quantum Design Inc.).

According to the Néel theory, the ferrimagnets that contain nonequivalent substructures of magnetic ions may have a number of unusual forms of M-T curves below the Curie temperature, depending on the distribution of magnetic ions between the substructures and on the relative value of the molecular field coefficients. The anomalous M-T curves of Mn₄C, as shown in FIG. 3(a), can be explained to some extent by the Néel's P-type ferrimagnetism, which appears when the sublattice with smaller moment is thermally disturbed more easily. For Mn₄C with two sublattices of Mn_I and Mn_II, as shown in FIG. 1, the Mn_I sublattice might have smaller moment.

FIG. 3(a) shows the temperature dependence of magnetization of the Mn₄C magnetic material produced in Example 1. The magnetization of Mn₄C measured at 4.2K is 6.22 Am²/kg (4 T), corresponding to 0.258μ_B per unit cell. The magnetization of the Mn₄C magnetic material varies little at temperatures below 50 K, and is quite different from that of most magnetic materials, which undergo a magnetization deterioration with increasing temperature due to thermal agitation. Furthermore, the magnetization of the Mn₄C magnetic material increases linearly with increasing temperature at temperatures above 50 K. The linear fitting of the magnetization of Mn₄C at 4 T within the temperature range of 100 K to 400 K can be written as M=0.0072T+5.6788, where M and T are expressed in Am²/kg and K, respectively. Thus, the temperature coefficient of magnetization of Mn₄C is estimated to be about ˜2.99*10⁻⁴μ_B/K per unit cell. The mechanisms of the anomalous thermomagnetic behaviors of Mn₄C may be related to the magnetization competition of the two ferromagnetic sublattices (Mn_I and Mn_II) as shown in FIG. 1.

FIG. 3(b) shows the M-T curves of the Mn₄C powders at temperatures within the range of 300 K to 930 K under 1 T. The linear magnetization increment stops at 590 K, above which the magnetization of Mn₄C starts to decrease slowly first and then sharply at a temperature of about 860 K. The slow magnetization decrement at temperatures above 590 K is ascribed to the decomposition of Mn₄C, which is proved by further heat-treatment of Mn₄C as described below.

According to one embodiment of the present disclosure, the saturation magnetization of Mn₄C increases linearly with increasing temperature within the range of 50 K to 590 K and remains stable at temperatures below 50 K. The increases in anomalous magnetization of Mn₄C with increasing temperature can be considered in terms of the Néel's P-type ferrimagnetism. At temperatures above 590 K, the Mn₄C decomposes into Mn₂₃C₆ and Mn, which are partially oxidized into the manganosite when exposed to air. The remanent magnetization of Mn₄C varies little with temperature. The Curie temperature of Mn₄C is about 870 K. The positive temperature coefficient (about 0.0072 Am²/kgK) of magnetization in Mn₄C is potentially important in controlling the thermodynamics of magnetization in magnetic materials.

The Curie temperature T_e of Mn₄C is measured to be about 870 K, as shown in FIG. 3(c). Therefore, the sharp magnetization decrement of Mn₄C at temperatures above 860 K is ascribed to both the decomposition of Mn₄C and the temperature near the Tc of Mn₄C.

FIG. 4 is a graph showing the magnetic hysteresis loops of the Mn₄C magnetic material, produced according to Example 1 of the present disclosure, at 4.2 K, 200 K and 400 K. The magnetic hysteresis loops were measured by using the PPMS system (Quantum Design) under a magnetic field of 7 T while the temperature was changed from 4 K to 400 K.

As shown in FIG. 4, the positive temperature coefficient of magnetization was further proved by the magnetic hysteresis loops of Mn₄C as shown in FIG. 4. The Mn₄C shows a much higher magnetization at 400 K than that at 4.2 K. Moreover, the remanent magnetization of Mn₄C varies little with temperature and is Δ3.5 Am²/kg within the temperature range of 4.2 K to 400 K. The constant remanent magnetization of Mn₄C within a wide temperature range indicates the high stability of magnetization against thermal agitation. The coercivities of Mn₄C at 4.2 K, 200 K, and 400 K were 75 mT, 43 mT, and 33 mT, respectively.

The magnetic properties of Mn₄C measured are different from the previous theoretical results. A corner Mn_I moment of 3.85μ_B antiparallel to three face-centered Mn_II moments of 1.23μ_B in Mn₄C was expected at 77 K. The net moment per unit cell was estimated to be 0.16μ_B. In the above experiment, the net moment in pure Mn₄C at 77 K is 0.26μ_B/unit cell, which is much larger than that expected by Takei et al. It was reported that the total magnetic moment of Mn₄C was calculated to be about 1μ_B, which is almost four times larger than the 0.258μ_B per unit cell measured at 4.2 K, as shown in FIG. 4.

FIG. 5 is an enlarged view of the temperature-dependent XRD patterns of the Mn₄C magnetic material produced according to Example 1 of the present disclosure.

The thermomagnetic behaviors of Mn₄C are related to the variation in the lattice parameters of Mn₄C with temperature. It is known that the distance of near-neighbor manganese atoms plays an important role in the antiferro- or ferro-magnetic configurations of Mn atoms. Ferromagnetic coupling of Mn atoms is possible only when the Mn—Mn distance is large enough. FIG. 5 shows the diffraction peaks of the (111) and (200) planes of Mn₄C at temperatures from 16 K to 300 K. With increasing temperature, both (111) and (200) peaks of Mn₄C shifted to a lower degree at temperatures between 50 K and 300 K, indicating an enlarged distance of Mn—Mn atoms in Mn₄C. No peak shift is obviously observed for Mn₄C at temperatures below 50 K. The distance of nearest-neighbor manganese atoms plays an important role in the antiferro- or ferro-magnetic configurations of Mn atoms and thus has a large effect on the magnetic properties of the compounds.

Thus, it can be seen that the abnormal increase in magnetization of Mn₄C with increasing temperature occurs due to the variation in the lattice parameters of Mn₄C with temperature.

The powder produced in Example 1 was annealed in vacuum for 1 hour at each of 700 K and 923 K, and then subjected to X-ray spectroscopy, and the results thereof are shown in FIG. 6.

The magnetization reduction of Mn₄C at temperatures above 590 K is ascribed to the decomposition of Mn₄C, which is proved by the XRD patterns of the powders after annealing Mn₄C at elevated temperatures. FIG. 6 shows the structural evolution of Mn₄C at elevated temperatures. When Mn₄C is annealed at 700 K, a small fraction of Mn₄C decomposes into a small amount of Mn₂₃C₆ and Mn. The presence of manganosite is ascribed to the spontaneous oxidation of the Mn precipitated from Mn₄C when exposed to air after annealing. The fraction of Mn₂₃C₆ was enhanced significantly for Mn₄C annealed at 923 K, as shown in FIG. 6.

These results prove that the metastable Mn₄C decomposes into stable Mn₂₃C₆ at temperatures above 590 K. The presence of Mn₄C in the powder annealed at 923 K indicates a limited decomposition rate of Mn₄C, from which the Tc of Mn₄C can be measured. Both Mn₂₃C₆ and Mn are weak paramagnets at ambient temperature and elevated temperatures. Therefore, the magnetic transition of the Mn₄C magnetic material at 870 K is ascribed to the Curie point of the ferrimagnetic Mn₄C.

The Mn₄C shows a constant magnetization of 0.258μ_B per unit cell below 50 K and a linear increment of magnetization with increasing temperature within the range of 50 K to 590 K, above which Mn₂₃C₆ precipitates from Mn₄C. The anomalous M-T curves of Mn₄C can be considered in terms of the Néel's P-type ferrimagnetism.