Abstract
The data presented in this article are related to research articles “Titanium and vanadium catalysts with oxazoline ligands for ethylene-norbornene (co)polymerization (Ochędzan-Siodłak et al., 2018). For the title compounds, 2-(1,3-oxazolin-2-yl)pyridine (Py-ox) and 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box), the single-crystal X-ray diffraction measurement together with NMR, GC, MS, DSC analysis, like also the method of crystallization are presented.
Keywords: Ligands, Oxazoline, Pyridine, Conformation, Association
Specifications table
| Subject area | Chemistry |
| More specific subject area | Organic Chemistry, Ligands for Catalysts |
| Type of data | Figures, tables, text file. |
| X-ray (table, figures), GC–MS (Figures), 13C NMR (figures), DSC (figures), synthesis (text) | |
| How data was acquired | X-ray (Xcalibur diffractometer), |
| NMR (Bruker Ultrashield spectrometer 400 MHz, solvent DMSO-d6), | |
| GC–MS (Hewlett Packard HP7890 A GC system) | |
| DSC (2010 TA calorimeter) | |
| Data format | X-ray (analyzed), GC–MS (raw), NMR (raw), DSC (raw) |
| Experimental factors | Crystallization at room temperature. Py-ox - highly anhydrous toluene/hexane mixture, Py-box - DMSO-d6 in NMR tube. |
| Experimental features | Highly anhydrous condition for crystals are required. |
| Data source location | City: Opole, Country: Poland, Latitude: N 50°40′23.981″, Longitude: E 17°55′53.173′, (Lat,Long: 50.673328, 17.93143699999996), |
| Data accessibility | The Cambridge Crystallographic Data Centre no. CCDC 1815355 and CCDC 1580983 (http://www.ccdc.cam.ac.uk/conts/retrieving.html, email:deposit@ccdc.cam.ac.uk.). |
Value of the data
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X-Ray structural information for Py-ox and Py-box compounds not coordinated by metal atom is presented.
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Conformation and association pattern in the crystal state is shown.
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Crystallization methods are shown.
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Purification for Py-ox is improved.
1. Data
The presented compounds, 2-(1,3-oxazolin-2-yl)pyridine (Py-ox) and 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box), are commonly applied as ligands for complexes with transition metals: cobalt [2], rhenium [3], platinum and palladium [4], [5] for Py-ox, as well as copper [6], [7], ruthenium [8], [9], [10], [11], rhodium [12], manganese [13], silver [14], nickel [15], cobalt [16], terbium [17], and iron [18], in the case of Py-box. Some of them reveal catalytic properties. In our work, the Py-ox and Py-box compounds were applied as ligands for titanium and vanadium complexes, which turned out to be active in polymerization of ethylene and copolymerization of ethylene with norbornene [1]. The X-Ray information for Py-ox and Py-box compounds can be important for comparative studies, to show differences between these compounds not coordinated by metal atom and applied as ligands. It can help to understand dependence between the structure and activity of the designed complexes. The presented crystallization methods are worth to notice. The improved method of purification enable to obtain the studied compound of high quality.
2. Experimental design, materials and methods
2.1. Synthesis
2.1.1. 2-(1,3-oxazolin-2-yl)pyridine (Py-ox)
The synthesis was performed mainly according to Stokes et al. [19]. The crude product was subjected to flash chromatography using the MeOH: AcOEt (1:4) mixture as eluent. Yield 60%. Elemental analysis C8H8N2O results: calculated C 64.85%, H 5.44%, N 18.91%, experimental C 64.92%, H 5.45%, N 19.09%. 1H NMR (400 MHz, DMSO-d6) δ 8.65 (1H, J = 4.5 Hz, d), 7.99 (1H, J = 8.0 Hz, d), 7.93 (1H, J = 7.8 Hz, td), 7.54 (1H, m), 4.45 (2H, J = 9.6 Hz, t), 4.00 (2H, J = 9.6 Hz, t). 13C NMR (400 MHz, DMSO-d6) δ 162.98, 149.53, 146.52, 137.09, 125.90, 123.80, 67.66, 54.61. GC–MS M+ 148 m/e. Melting temperature 57.0 (54.6–60.0) °C.
2.1.2. 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box)
The synthesis was performed mainly according to Zhu et al. [20]. Yield 76%. Elemental analysis C11H11N3O2 results: calculated C 64.82%, H 5.10%, N 19.34%, experimental: C 64.88%, H 5.12%, N 19.39%. 1H NMR (400 MHz, DMSO-d6) δ 8.11 (2H, J1 = 1.2 Hz, J2 = 7.2 Hz, t), 8.02(1H, J1 = 6.4 Hz, J2 = 2.4 Hz, q), 4.45 (4H, J = 9.6 Hz, t), 4.01 (4H, J = 9.6 Hz, t). 13C NMR (400 MHz, DMSO-d6) δ 163.10, 147.01, 138.46, 126.00, 68.28, 55.13. GC–MS M+ 217 m/e. Melting temperature 160.6 (159.4–163.0) °C.
2.2. Crystallization
2.2.1. 2-(1,3-oxazolin-2-yl)pyridine (Py-ox)
The crystals were obtained at room temperature from highly anhydrous toluene/hexane mixture. The solvents were freshly distilled over sodium. The highly anhydrous conditions are crucial. All operations were performed in a glove-box filled with argon. Py-ox (20 mg) was placed in a 5 ml snap cap vial with plastic cap and dissolved in toluene (1 ml). Then, hexane (1 ml) was added and the solution was left to stand at room temperature for a week.
2.2.2. 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box)
The crystals of appropriate quality were obtained at room temperature from DMSO-d6 solution by long standing time in NMR tube. All operations were performed in a glove-box filled with argon. DMSO-d6 solvent from sealed glass ampoules was applied. Py-box (15 mg) and DMSO-d6 (0.6 ml) was placed in NMR tube and the cap was sealed by a parafilm. The solution was left to stand at room temperature for a month.
2.3. X-ray
The single-crystal X-ray diffraction experiments were performed at 293.0(1)K on the Xcalibur diffractometer, equipped with a CCD area detector and a graphite monochromator for the MoKα radiation. The reciprocal space was explored by ω scans with detector positions at 60 mm distance from the crystal. The diffraction data processing of studied compounds (Lorentz and polarization corrections were applied) were performed using the CrysAlis CCD [21], [22]. Both structures Py-ox and Py-box were solved in the C2 and P2/n space group respectively, by direct methods and refined by a full-matrix least-squares method using SHELXL14 program [23], [24]. The H atoms were found based on geometrical parameters. In both structures H atoms were refined using a riding model. The structure drawings were prepared using SHELXTL and Mercury programs [25] (Fig. 1, Fig. 2, Fig. 3 and Table 1, Table 2).
Fig. 1.
Molecular conformation of Py-ox (a) and Py-box (b) with atom labeling and the displacement ellipsoids at 50% probability level.
Fig. 2.
Association of molecule in the crystal structure. Hydrogen contacts are marked by dashed lines. The numbers of atoms and distances are omitted for clarity. All geometric parameters are in Table 2.
Fig. 3.
The crystal packing scheme of the title compounds. A view along the c axis of the crystals packing.
Table 1.
X-ray experimental details for 2-(1,3-oxazolin-2-yl)pyridine (Py-ox) and 2,6-bis(1,3-oxazolin-2-yl) pyridine (Py-box).
| Py-ox | Py-box | |
|---|---|---|
| Chemical formula | C8H8N2O | C11H11N3O2 |
| Mr | 148.16 | 217.23 |
| Crystal system, space group | Monoclinic, C2 | Monoclinic, P2/n |
| a, b, c (Å) | 10.2571 (7), 10.0159 (6), 14.4647 (9) | 6.4904 (8), 6.5835 (11), 11.9080 (19) |
| β (°) | 97.497 (6) | 94.215 (13) |
| V (Å3) | 1473.31 (16) | 507.45 (13) |
| Z | 8 | 2 |
| Measurement temperature | 293.0(1) | 293.0(1) |
| µ (mm−1) | 0.09 | 0.10 |
| Crystal size (mm) | 0.4 × 0.3 × 0.2 | 0.5 × 0.4 × 0.3 |
| Crystal colour | Colourless | |
| Crystal description | Plate | |
| Data collection | ||
| Radiation wavelength | 0.71073 | |
| Radiation type | MoKα | |
| Source | fine-focus sealed tube | |
| Measurement device type | Xcalibur | |
| Detector area resolution | 1024 × 1024 with blocks 2 × 2 | |
| Absorption correction | – | |
| No. of measured, independent and observed [I>2σ(I)] reflections | 5,034, 2786, 1587 | 3,172, 993, 459 |
| Rint | 0.018 | 0.048 |
| (sin θ/λ)max (Å−1) | 0.617 | 0.616 |
| Refinement | ||
| R[F2>2σ(F2)], wR(F2), S | 0.030, 0.077, 0.86 | 0.057, 0.173, 0.87 |
| No. of reflections | 2786 | 993 |
| No. of parameters | 200 | 75 |
| No. of restraints | 1 | 0 |
| Δρmax, Δρmin (e Å−3) | 0.11, −0.09 | 0.22, −0.18 |
Table 2.
Selected geometric parameters (Å, °) for Py-ox and Py-box molecules.
| Structure 2 (Py-ox) | |||
|---|---|---|---|
| N1A-C2A | 1.386 (7) | C5B-H5B | 0.9300 |
| N1A-C6A | 1.394 (6) | C7A-N8A | 1.292 (7) |
| C2A-C3A | 1.367 (8) | C7A-O11A | 1.314 (6) |
| C2A-H2A | 0.9300 | C6B-C7B | 1.478 (7) |
| N1B-C6B | 1.360 (6) | N8A-C9A | 1.423 (7) |
| N1B-C2B | 1.393 (7) | C7B-N8B | 1.289 (6) |
| C3A-C4A | 1.400 (8) | C7B-O11B | 1.292 (7) |
| C3A-H3A | 0.9300 | C9A-C10A | 1.518 (8) |
| C2B-C3B | 1.344 (9) | C9A-H9AA | 0.9700 |
| C2B-H2B | 0.9300 | C9A-H9AB | 0.9700 |
| C4A-C5A | 1.307 (8) | N8B-C9B | 1.427 (7) |
| C4A-H4A | 0.9300 | C10A-O11A | 1.470 (7) |
| C3B-C4B | 1.361 (9) | C10A-H10A | 0.9700 |
| C3B-H3B | 0.9300 | C10A-H10B | 0.9700 |
| C5A-C6A | 1.335 (6) | C9B-C10B | 1.513 (8) |
| C5A-H5A | 0.9300 | C9B-H9BA | 0.9700 |
| C4B-C5B | 1.345 (7) | C9B-H9BB | 0.9700 |
| C4B-H4B | 0.9300 | O11B-C10B | 1.488 (6) |
| C6A-C7A | 1.464 (7) | C10B-H10C | 0.9700 |
| C5B-C6B | 1.342 (6) | C10B-H10D | 0.9700 |
| C2A-N1A-C6A | 116.2 (5) | C5B-C6B-C7B | 119.1 (5) |
| C3A-C2A-N1A | 122.5 (6) | N1B-C6B-C7B | 117.4 (5) |
| C3A-C2A-H2A | 118.8 | C7A-N8A-C9A | 106.3 (5) |
| N1A-C2A-H2A | 118.8 | N8B-C7B-O11B | 119.6 (6) |
| C6B-N1B-C2B | 115.8 (5) | N8B-C7B-C6B | 120.4 (6) |
| C2A-C3A-C4A | 116.1 (6) | O11B-C7B-C6B | 120.0 (5) |
| C2A-C3A-H3A | 122.0 | N8A-C9A-C10A | 106.9 (6) |
| C4A-C3A-H3A | 122.0 | N8A-C9A-H9AA | 110.3 |
| C3B-C2B-N1B | 121.2 (6) | C10A-C9A-H9AA | 110.3 |
| C3B-C2B-H2B | 119.4 | N8A-C9A-H9AB | 110.3 |
| N1B-C2B-H2B | 119.4 | C10A-C9A-H9AB | 110.3 |
| C5A-C4A-C3A | 123.3 (6) | H9AA-C9A-H9AB | 108.6 |
| C5A-C4A-H4A | 118.3 | C7B-N8B-C9B | 105.7 (5) |
| C3A-C4A-H4A | 118.3 | O11A-C10A-C9A | 101.9 (4) |
| C2B-C3B-C4B | 120.0 (6) | O11A-C10A-H10A | 111.4 |
| C2B-C3B-H3B | 120.0 | C9A-C10A-H10A | 111.4 |
| C4B-C3B-H3B | 120.0 | O11A-C10A-H10B | 111.4 |
| C4A-C5A-C6A | 119.6 (6) | C9A-C10A-H10B | 111.4 |
| C4A-C5A-H5A | 120.2 | H10A-C10A-H10B | 109.3 |
| C6A-C5A-H5A | 120.2 | N8B-C9B-C10B | 106.8 (4) |
| C5B-C4B-C3B | 120.2 (6) | N8B-C9B-H9BA | 110.4 |
| C5B-C4B-H4B | 119.9 | C10B-C9B-H9BA | 110.4 |
| C3B-C4B-H4B | 119.9 | N8B-C9B-H9BB | 110.4 |
| C5A-C6A-N1A | 122.4 (5) | C10B-C9B-H9BB | 110.4 |
| C5A-C6A-C7A | 118.1 (5) | H9BA-C9B-H9BB | 108.6 |
| N1A-C6A-C7A | 119.6 (5) | C7A-O11A-C10A | 106.8 (5) |
| C6B-C5B-C4B | 119.1 (5) | C7B-O11B-C10B | 106.1 (5) |
| C6B-C5B-H5B | 120.5 | O11B-C10B-C9B | 101.7 (5) |
| C4B-C5B-H5B | 120.5 | O11B-C10B-H10C | 111.4 |
| N8A-C7A-O11A | 118.1 (5) | C9B-C10B-H10C | 111.4 |
| N8A-C7A-C6A | 122.8 (5) | O11B-C10B-H10D | 111.4 |
| O11A-C7A-C6A | 119.1 (6) | C9B-C10B-H10D | 111.4 |
| C5B-C6B-N1B | 123.6 (5) | H10C-C10B-H10D | 109.3 |
| Symmetry code(s): (i) −x+1/2, y, −z+1/2. | |||
| Structure 1 (Py-Box) | |||
| N1-C2i | 1.355 (3) | C5-O9 | 1.316 (4) |
| N1-C2 | 1.355 (3) | N6-C7 | 1.448 (4) |
| C2-C3 | 1.381 (4) | C7-C8 | 1.502 (4) |
| C2-C5 | 1.468 (4) | C7-H7A | 0.9700 |
| C3-C4 | 1.380 (4) | C7-H7B | 0.9700 |
| C3-H3 | 0.9300 | C8-O9 | 1.471 (3) |
| C4-C3i | 1.380 (4) | C8-H8A | 0.9700 |
| C4-H4 | 0.9300 | C8-H8B | 0.9700 |
| C5-N6 | 1.293 (3) | ||
| C2i-N1-C2 | 116.0 (4) | N6-C7-C8 | 105.1 (2) |
| N1-C2-C3 | 123.4 (3) | N6-C7-H7A | 110.7 |
| N1-C2-C5 | 116.5 (3) | C8-C7-H7A | 110.7 |
| C3-C2-C5 | 120.0 (2) | N6-C7-H7B | 110.7 |
| C4-C3-C2 | 119.5 (3) | C8-C7-H7B | 110.7 |
| C4-C3-H3 | 120.2 | H7A-C7-H7B | 108.8 |
| C2-C3-H3 | 120.2 | O9-C8-C7 | 104.0 (3) |
| C3i-C4-C3 | 118.1 (4) | O9-C8-H8A | 110.9 |
| C3i-C4-H4 | 121.0 | C7-C8-H8A | 110.9 |
| C3-C4-H4 | 121.0 | O9-C8-H8B | 110.9 |
| N6-C5-O9 | 118.1 (2) | C7-C8-H8B | 110.9 |
| N6-C5-C2 | 121.0 (3) | H8A-C8-H8B | 109.0 |
| O9-C5-C2 | 120.9 (2) | C5-O9-C8 | 105.8 (2) |
| C5-N6-C7 | 106.9 (2) | ||
2.3.1. 2-(1,3-oxazolin-2-yl)pyridine (Py-ox)
2.3.2. 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box)
2.4. NMR
Bruker Ultrashield spectrometer 400 MHz, solvent DMSO-d6, TMS standard. Concentration: 15 mg in 0.6 ml (Fig. 4, Fig. 5, Fig. 6, Fig. 7).
Fig. 4.
1H NMR spectrum for 2-(1,3-oxazolin-2-yl)pyridine (Py-ox) in DMSO-d6.
Fig. 5.
13C NMR spectrum for 2-(1,3-oxazolin-2-yl)pyridine (Py-ox) in DMSO-d6.
Fig. 6.
1H NMR spectrum for 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box) in DMSO-d6.
Fig. 7.
13C NMR spectrum for 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box) in DMSO-d6.
2.5. GC–MS
Hewlett Packard HP7890 A GC system, equipped with 7000 GC/MS triple-quadrupol and HP-5 capilar 300 m × 0.32 mm column with 0.25 µm dimethylpolysilloxane stationary phase, dopped by 5% of phenylpolysilloxane (Fig. 8, Fig. 9, Fig. 10, Fig. 11).
Fig. 8.
GC analysis of 2-(1,3-oxazolin-2-yl)pyridine (Py-ox).
Fig. 9.
MS analysis of 2-(1,3-oxazolin-2-yl)pyridine (Py-ox).
Fig. 10.
GC analysis of 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box).
Fig. 11.
MS analysis of 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box).
2.6. DSC
The melting temperatures were measured by differential scanning calorimetry DSC 2010 TA instrument calorimeter equipped with an automated sampler. The data were collected with the heat/cool/heat cycle at a heating rate of 10 °C/min under a nitrogen atmosphere (Figs. 12 and 13).
Fig. 12.
DSC analysis of 2-(1,3-oxazolin-2-yl)pyridine (Py-ox).
Fig. 13.
DSC analysis of 2,6-bis(1,3-oxazolin-2-yl)pyridine (Py-box).
Footnotes
Transparency data associated with this article can be found in the online version at https://doi.org/10.1016/j.dib.2018.09.129.
Transparency document. Supplementary material
Supplementary material.
.
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