17536-00-4Relevant academic research and scientific papers
The crystal structure of 3,5-diisopropyl-4-nitropyrazole from X-ray powder diffraction data
Ochando,Amigó,Rius,Lou?r,Fontenas,Elguero
, p. 11 - 17 (2001)
The crystal structure of 3,5-diisopropyl-4-nitropyrazole, 3c, has been determined by a Patterson Search method from laboratory X-ray powder diffraction data. The crystal data are: monoclinic symmetry with the unit-cell parameters a = 19.530(5), b = 6.485(1) and c = 17.937(3) ?,β = 100.32(1)°, space group 12/a, C9H15N3O2, Z = 8, 293 K. After indexing the powder pattern by two methods, the unit-cell parameters found were refined by a least-squares technique. A whole pattern-fitting program was used to extract the integrated intensities. The structure was solved taking a related compound as a search model and the final Rietveld refinement converged to Rwp = 0.1971 and Rp = 0.1437. The structure presents a dimer conformation between N atoms through a hydrogen bond.
SULFONIMIDAMIDE COMPOUNDS AS INHIBITORS OF INTERLEUKIN-1 ACTIVITY
-
Paragraph 0646, (2020/02/14)
The present disclosure relates to novel sulfonimidamide compounds and related compounds and their use in treating a disorder responsive to modulation of cytokines such as IL-1β and IL-18, modulation of NLRP3 or inhibition of the activation of NLRP3 or related components of the inflammatory process. (I)
Versatile Tri(pyrazolyl)phosphanes as Phosphorus Precursors for the Synthesis of Highly Emitting InP/ZnS Quantum Dots
Panzer, René,Guhrenz, Chris,Haubold, Danny,Hübner, René,Gaponik, Nikolai,Eychmüller, Alexander,Weigand, Jan J.
supporting information, p. 14737 - 14742 (2017/10/23)
Tri(pyrazolyl)phosphanes (5R1,R2) are utilized as an alternative, cheap and low-toxic phosphorus source for the convenient synthesis of InP/ZnS quantum dots (QDs). From these precursors, remarkably long-term stable stock solutions (>6 months) of P(OLA)3 (OLAH=oleylamine) are generated from which the respective pyrazoles are conveniently recovered. P(OLA)3 acts simultaneously as phosphorus source and reducing agent in the synthesis of highly emitting InP/ZnS core/shell QDs. These QDs are characterized by a spectral range between 530–620 nm and photoluminescence quantum yields (PL QYs) between 51–62 %. A proof-of-concept white light-emitting diode (LED) applying the InP/ZnS QDs as a color-conversion layer was built to demonstrate their applicability and processibility.
Synthesis, crystal structure and photophysical study of luminescent three-coordinate cuprous bromide complexes based on pyrazole derivatives
Wu, Fengshou,Tong, Hongbo,Wang, Kai,Zhang, Xiulan,Zhang, Jie,Wong, Wai-Kwok,Zhu, Xunjin
, p. 926 - 933 (2016/04/08)
The 1: 2 M-ratio reaction between cuprous bromide and pyrazole derivatives in toluene results in mononuclear Cu(I) complexes [CuBr(pyrazole)2]. The complexes have been characterized by 1H NMR spectroscopy and elemental analysis. The molecular structure, established by single-crystal X-ray diffraction, features a trigonal planar geometry around copper, with monodentate pyrazole derivatives. All the Cu(I) complexes are luminescent in the solid state at ambient temperature. Intense blue or blue-green emission in the solid state is observed for these complexes, with the maxima ranging from 431 to 493 nm. The observed photoluminescence could be ascribed to the metal-to-ligand charge-transfer excited states, probably mixed with some halide-to-ligand character. The microsecond lifetime scale of the complexes implies that these transitions arise from the triplet excited states.
Synthesis of β-tosylethylhydrazine and its use in preparation of N-protected pyrazoles and 5-aminopyrazoles
Dastrup, David M.,Yap, Amy H.,Weinreb, Steven M.,Henry, James R.,Lechleiter, Andrew J.
, p. 901 - 906 (2007/10/03)
β-Tosylethylhydrazine (6) can be prepared efficiently in one step from commercially available p-tolyl vinyl sulfone (7) and hydrazine hydrate. This hydrazine reacts with both 1,3-diketones and conjugated ynones in glacial acetic acid to provide a variety of N-tosylethyl-protected (TSE) pyrazoles in good yields. The TSE group can be removed from the pyrazoles using potassium t-butoxide in THF at -30°C-rt. In addition, hydrazine 6 condenses with β-ketonitriles and β-aminoacrylonitriles to afford 5-aminopyrazoles, which can be deprotected by brief treatment with NaOEt in EtOH/DMSO at 45°C.
A new model for dioxygen binding in hemocyanin. Synthesis, characterization, and molecular structure of the μ-η2:η2 peroxo dinuclear copper(II) complexes, [Cu(HB(3,5-R2pz)3)]2(O2) (R = i-Pr and Ph)
Kitajima, Nobumasa,Fujisawa, Kiyoshi,Fujimoto, Chisato,Moro-oka, Yoshihiko,Hashimoto, Shinji,Kitagawa, Teizo,Toriumi, Koshiro,Tatsumi, Kazuyuki,Nakamura, Akira
, p. 1277 - 1291 (2007/10/02)
The synthesis and characterization of μ-η2:η2 peroxo dinuclear copper(II) complexes which show many similarities to oxyhemocyanin (or oxytyrosinase) in their physicochemical properties are presented. The low-temperature reaction of a di-μ-hydroxo copper(II) complex [Cu(HB(3,5-i-Pr2pz)3)]2(OH)2 (8) with H2O2 gave a μ-peroxo complex [Cu(HB(3,5-i-Pr2pz)3)]2(O2) (6). Complex 6 was also prepared by dioxygen addition to a copper(I) complex Cu(HB(3,5-i-Pr2pz)3) (9). The preparation of an analogous peroxo complex [Cu(HB(3,5-Ph2pz)3)]2(O2) (7) was accomplished by the similar dioxygen treatment of a copper(I) acetone adduct Cu(Me2CO)(HB(3,5-Ph2pz)3) (10). The reaction of 6 with CO or PPh3 causes release of dioxygen, resulting in formation of the corresponding copper(I) adduct, Cu(CO)(HB(3,5-i-Pr2pz)3) (11) or Cu(PPh3)(HB(3,5-i-Pr2pz)3) (12). Crystallography was performed for 6-6(CH2Cl2), 8-1.5(CH2Cl2), and 11. Compound 6-6(CH2Cl2) crystallizes in the monoclinic space group C2/c with a = 26.36 (2) A?, b = 13.290 (4) A?, c = 29.29 (2) A?, β= 114.59 (6)°, V = 7915 (9) A?3, and Z = 4. The refinement converged with the final R (Rw) value, 0.101 (0.148), for 3003 reflections with F ≥ 3σ(Fo). Compound 8-1.5(CH2Cl2) crystallizes in the triclinic space group P1? with a = 16.466 (4) A?, b = 16.904 (5) A?, c = 14.077 (3) A?, a = 112.92 (2)°, β= 99.21 (2)°, γ = 90.76 (2)°, V = 3550 (2) A?3, Z = 2, and the final R (Rw) factor, 0.083 (0.105), for 7226 reflections with F ≥ 3σ(Fo). Compound 11 crystallizes in the monoclinic space group, P21/a with a = 16.595 (4) A?, b = 19.154 (4) A?, c = 10.359 (2) A?, β= 106.65 (2)°, V = 3155 (1) A?3, Z = 4, and the final R (Rw) value 0.083 (0.074) for 5356 reflections with F ≥ 3σ(Fo). The X-ray analysis of 6-6(CH2Cl2) definitely established the μ-η2:η2 coordination structure of the peroxide ion for the first time. This unusual side-on structure is entirely novel for a d-block element transition-metal-dioxygen complex. Both 6 and 7 show remarkable characteristics which are very similar to those known for oxyhemocyanin and oxytyrosinase. Complex 6: diamagnetic; ν(O-O), 741 cm-1; UV-vis, 349 nm (ε, 21 000), 551 nm (ε, 790); Cu-Cu, 3.56 A?. Complex 7: diamagnetic, ν(O-O), 759 cm-1; UV-vis, 355 nm (ε, 18 000), 542 nm (ε, 1040). These properties are all consistent with those of an analogous complex, [Cu(HB(3,5-Me2pz)3)]2(O2) (5), of which the characterization and reactivities were reported already (Kitajima, N., et al. J. Am. Chem. Soc. 1990, 112, 6402; 1991, 113, 5664). The magnetic and spectroscopic features of 5-7 and their biological relevance are discussed in detail. Furthermore, simple interpretation of the electronic state of the N3Cu(O22-)CuN3 chromophore is provided based on extended Hu?ckel MO calculations. The close resemblance between the properties of μ-η2:η2 peroxo complexes 5-7 and oxyhemocyanin led us to propose a new model for dioxygen binding in hemocyanin; dioxygen is simply bound between the two copper ions in the μ-η2:η2 mode. With this structural model; the existence of an endogenous bridging ligand, which has been generally supposed to account for the diamagnetism of oxyhemocyanin, is no longer necessary.
Preparations of Copper(I) Complexes Ligated with Novel Hindered Pyrazolylborates
Kitajima, Nobumasa,Fujisawa, Kiyoshi,Fujimoto, Chisato,Moro-Oka, Yoshihiko
, p. 421 - 424 (2007/10/02)
Novel hindered pyrazolylborates, HB(3,5-Ph2pz)3- and HB(3,5-iPr2pz)3- were synthesized.Several copper(I) complexes ligated with these ligands were prepared and their properties are compared with the corresponding complexes with conventional pyrazolylborate as ligand.
