2398-81-4Relevant articles and documents
Two series of reactant's ratio-dependent lanthanide organic frameworks derived from nicotinic acid N-oxide and oxalate: Synthesis, crystal structures and luminescence properties
Yu, Yanyan,Zhang, Lijuan,Zhou, Yunshan,Zuhra, Zareen
, p. 4601 - 4612 (2015)
Two series of lanthanide(iii)-organic frameworks with the molecular formula [Ln2(NNO)2(OX)2(H2O)4]n (Ln = Eu 1, Tb 2, Sm 3, Dy 4, Gd 5) and [Ln2(NNO)4(OX)(H2O)2]n (Ln = Eu 6, Tb 7, Sm 8, Dy 9, Gd 10) were synthesized successfully under the same hydrothermal conditions with nicotinic N-oxide (HNNO) and oxalic acid (H2OX) as the mixed ligands merely through varying the molar ratio of the reactants. The compounds were characterized by IR, elemental analysis, UV, TG-DTA and powder X-ray diffraction (XRD). X-ray single-crystal diffraction analyses of compounds 1 and 7 selected as representatives and powder XRD analysis of the compounds revealed that both the series of compounds feature three-dimensional (3-D) open frameworks, and crystallize in the triclinic P1 space group while with different unit cell parameters. In compound 1, pairs of Eu3+ ions and pairs of NNO- ligands connect with each other alternately to form a 1-D infinite Eu-NNO double chain, the adjacent 1-D double-chains are then joined together through OX2- ligands leading to a 2D layer, the 2-D layers are further 'pillared' by OX2- ligands resulting in a 3-D framework. In compound 7, the 1-D Tb-NNO infinite chain and its 2-D layer are formed in an almost similar fashion to that in compound 1. The difference between the structures of the two compounds 1 and 7 is that the adjacent 2-D layers in compound 7 are further connected by NNO- ligands resulting in a 3-D framework. The photoluminescence properties and energy transfer mechanism of the compounds were studied systematically. The energy level of the lowest triplet states of the HNNO ligand (23148 cm-1) was determined based on the phosphorescence spectrum of compound 5 at 77 K. The 5D0 (Eu3+) and 5D4 (Tb3+) emission lifetimes are 0.46 ms, 0.83 ms, 0.69 ms and 0.89 ms and overall quantum yields are 1.03%, 3.29%, 2.58% and 3.78% for the compounds 1, 2, 6 and 7, respectively. This journal is
Recyclable anhydride catalyst for H2O2 oxidation:: N -oxidation of pyridine derivatives
Gajeles, Ghellyn,Kim, Se Mi,Lee, Kyung-Koo,Lee, Sang Hee,Yoo, Jong-Cheol
, p. 9165 - 9171 (2020/03/13)
The catalytic efficiency and recyclability of poly(maleic anhydride-alt-1-octadecene) (Od-MA) and poly(maleic anhydride-alt-1-isobutylene) (Bu-MA) were evaluated for use in the development of a metal-free, reusable catalyst for the oxidation of pyridines to pyridine N-oxides in the presence of H2O2. The Od-MA catalyst was easily recovered via filtration with recovery yields exceeding 99.8%. The catalyst retained its activity after multiple uses and did not require any treatment for reuse. The Od-MA and H2O2 catalytic system described herein is eco-friendly, operationally simple, and cost-effective; thus, it is industrially applicable. Od-MA and H2O2 could potentially be used in place of percarboxylic acid as an oxidant in a wide range of oxidation reactions.
New green technology for preparation of 2-chloronicotinic acid
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Paragraph 0026; 0027; 0030; 0031, (2019/01/24)
The invention relates to a new green technology for preparation of 2-chloronicotinic acid. The technology includes: adopting nicotinic acid (I) as the raw material, conducting hydrogen peroxide N-oxidation under the action of a catalyst in a water system to obtain nicotinic acid N-oxide (II), then under the action of organic base, conducting phosphorus oxychloride chlorination to synthesize 2-chloronicotinyl chloride (III), and then performing hydrolysis and refining to obtain 2-chloronicotinic acid (IV). The method avoids the use of benzene and acetic acid, has the advantages of short process, safety and environmental protection, good product quality and high yield, is an environment-friendly green synthetic route, and is suitable for industrial production.
