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Mononuclear copper (II) complexes containing 2,2'-dipyridylamine and hydroxybenzoate derivatives as catalyst for aerobic oxidation of hydroxamic acids |
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| รหัสดีโอไอ | |
| Title | Mononuclear copper (II) complexes containing 2,2'-dipyridylamine and hydroxybenzoate derivatives as catalyst for aerobic oxidation of hydroxamic acids |
| Creator | Wanassanan Chaisuriya |
| Contributor | Nantawat Wannarit, Advisor |
| Publisher | Thammasat University |
| Publication Year | 2566 |
| Keyword | Mononuclear Cu (II) complex, 2, 2'-dipyridylamine, Hydroxybenzoate derivatives, Crystal structure, Heterogeneous catalyst, Hydroxamic acid, สารเชิงซ้อนมอนอนิวเคลียร์คอปเปอร์ (II), อนุพันธ์ของไบพีริดิน, อนุพันธ์ไฮดรอกซีเบนโซเอต, โครงสร้างผลึก, ตัวเร่งปฏิกิริยาวิวิธพันธุ์, กรดไฮดรอกซามิก |
| Abstract | This research concerns the design, synthesis, characterization and catalytic properties of new mononuclear Cu(II) complexes containing 2,2'-dipyridylamine (dpyam) and hydroxybenzoate derivatives (x-OHbenz when x = 2-, 3-, and 4-hydroxy- benzoate). The mononuclear Cu(II) complexes have been classified into two series namely, a series I was designed with a general formula of [Cu(dpyam)(x-OHbenz)2], [Cu(dpyam)(3-OHbenz)(HCO2)] (1) and [Cu(dpyam)(4-OHbenz)2]·H2O (2) and a series II with a general formula of [Cu(dpyam)(x-OHbenz)Cl], when x = 2-OHbenz (3) and 3-OHbenz (4). All complexes were characterized by using FT-IR, UV-vis, solid-state diffuse reflectance spectroscopy, CHN elemental analysis, TGA and PXRD. The molecular structures of all complexes were determined by using single-crystal X-ray diffraction technique. The structures of Cu(II) complexes in a series I present different geometries, a distorted square-pyramidal with [CuN2O3] chromophore for complex 1 and a distorted square-planar with a [CuN2O2] chromophore for complex 2. Meanwhile, the Cu(II) complexes 3 and 4 in a series II are isostructural as a distorted square-pyramidal geometry with [CuN2O2Cl] chromophore. The crystal structures of these new mononuclear Cu(II) complexes were stabilized by various types of intermolecular interactions such as hydrogen bonding, π-π and C-H···π, and these supramolecular interactions have been confirmed by Hirshfeld surface analysis (dnorm) and two-dimensional fingerprint plots. Unfortunately, complex 1 could not be reproduced sufficiently for further catalysis studies. Consequently, the catalytic properties of complexes 2-4 have been investigated because they are insoluble in THF solution and stable at temperatures up to 250 C. Therefore, these complexes have been used as the heterogeneous catalyst in the aerobic oxidation reaction of hydroxamic acids to produce nitroso compounds. The progress of reactions was followed up by using the 1H-NMR technique. Interestingly, the result showed that complex 3 presents the most efficiency for catalyzing the reaction, giving the % yield of cycloadduct and ene-product up to 98%, and it could be reused at least five cycles with the TOF value of 15.29 h-1. In addition, the reaction mechanism was also proposed in this research. |
