Compound 40: Bis(ethyl 5-hydroxy-1-phenyl-1H-pyrazole-4-carboxylate)tetrakis(acetato)dirhodium

DOI: 10.14469/hpc/11395 Metadata

Created: 2022-10-12 09:50

Last modified: 2024-06-25 09:23

Author: Henry Rzepa

License: Creative Commons: Public Domain Dedication 1.0

Funding: (none given)

Description

Crystal structure, NMR and IR data for Bis(ethyl 5-hydroxy-1-phenyl-1H-pyrazole-4-carboxylate)tetrakis(acetato)dirhodium (40): [Rh2(OAc)4] (81.0 mg, 0.183 mmol, 1.00 equiv) was added with stirring to pyrazolone 6 (170 mg, 0.732 mmol, 4.00 equiv) in MeCN (4.0 mL) and the mixture was heated at reflux to 85 °C for 19 h, cooled to room temperature and evaporated to dryness. The residue was redissolved in CH2Cl2 (5.0 mL) and the complex was precipitated with the addition of hexanes (15 mL). The mixture was cooled in an ice-bath, the precipitate was collected by filtration and dried in vacuo. Rh-pyrazolone complex 39 (155 mg, 0.171 mmol, 93%) was obtained as a purple-red solid, essentially pure by its 1H NMR spectrum. Crystals suitable for X-ray crystallography were obtained from a CH2Cl2/hexanes solution. 1H-NMR (400 MHz, CD2Cl2): δ (ppm) = 8.08 (s, 2H), 7.80 (dd, J = 7.6, 1.7 Hz, 4H), 7.47 – 7.40 (m, 4H), 7.39 – 7.33 (m, 2H), 4.41 (q, J = 7.1 Hz, 4H), 1.72 (s, 12H), 1.40 (t, J = 7.1 Hz, 6H). 13C{1H}-NMR (101 MHz, CD2Cl2): δ (ppm) = 191.1, 166.5, 157.5, 148.0, 140.3, 136.8, 129.2, 129.0, 128.4, 125.7, 124.7, 119.5, 95.7, 61.4, 23.6, 14.6. IR (Diamond-ATR, neat) νmax (cm-1) = 3297, 1670, 1589, 1569, 1457, 1420, 1410, 1321, 1174, 1127, 965, 777, 751, 691. HRMS (ES-ToF) m/z: [M + H]+ calc. for ()+:, found:. m.p.: 210 – 212 °C (EtOH) (decomp.). Anal. Calcd for C32H36N4O14Rh2 ∙ 0.5 CH2Cl2 ∙ 0.5 C6H14: C, 42.98; H, 4.47; N, 5.65. Found: C, 43.37; H, 4.41; N, 5.57.

Member of collection / collaboration

DOIDescription
10.14469/hpc/10386 Syntheses and Characterization of Main Group, Transition Metal, Lanthanide and Actinide Complexes of Bidentate Acylpyrazolone Ligands

Members

DOIDescription
10.14469/hpc/11578 NMR Data for Compound 40.
10.14469/hpc/11577 IR Data for Compound 40.
10.14469/hpc/11416 Crystal structure data for Compound 40. Bis(ethyl 5-hydroxy-1-phenyl-1H-pyrazole-4-carboxylate)tetrakis(acetato)dirhodium

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