Polymerization Mechanism of Nitrogen-Containing Heteroaromatic Compound Under High-Pressure and High-Temperature Conditions
Polymerization Mechanism of Nitrogen-Containing Heteroaromatic Compound Under High-Pressure and High-Temperature Conditions
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含氮杂芳族化合物高压高温聚合机理
DOI：
10.1021/acs.jpca.0c08288
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Cody George D.
中科院分区：
文献类型：
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作者：
Shinozaki Ayako;Mimura Koichi;Nishida Tamihito;Cody George D.
以含氮杂环化合物1，5-萘啶为原料，在高温高压条件下进行聚合反应，合成了氢化氮化碳。在0.5GPa下，聚合在高于573 K的温度下显著进行，在1.5GPa下，聚合在高于623 K的温度下显著进行。反应温度相对低于纯萘的反应温度，表明当氮原子存在于芳环结构中时，反应温度显著降低。聚合反应在很大程度上进行，而N/C比没有显著变化。确定了三种类型的二聚;萘化，精确的二聚，和二聚与氢化，从气相色谱-质谱分析的可溶性产物。红外光谱分析表明，加氢产物中可能存在sp3碳和NH键。固体~（13）C核磁共振结果表明，在0.5和1.5GPa下合成的不溶性固体中，sp3/sp2比值均为0.14。不仅二聚体，而且可溶性较重的低聚物和不溶性聚合物通过更广泛的聚合形成。1，5-Nap的主要反应机理在0.5和1.5 GPa实验中是共同的，尽管所需的反应温度随着压力的增加而增加，并且芳环优先保持在较高的压力下。
Hydrogenated carbon nitride is synthesized by polymerization of 1,5-naphthyridine, a nitrogen-containing heteroaromatic compound, under high-pressure and high-temperature conditions. The polymerization progressed significantly at temperatures above 573 K at 0.5 GPa and above 623 K at 1.5 GPa. The reaction temperature was relatively lower than that observed for pure naphthalene, suggesting that the reaction temperature is considerably lowered when nitrogen atoms exist in the aromatic ring structure. The polymerization reaction largely progresses without significant change in the N/C ratio. Three types of dimerization are identified; naphthylation, exact dimerization, and dimerization with hydrogenation as determined from the gas chromatograph–mass spectrometry analysis of soluble products. Infrared spectra suggest that hydrogenation products were likely to be formed with sp3carbon and NH bonding. Solid-state13C nuclear magnetic resonance reveals that the sp3/sp2ratio is 0.14 in both the insoluble solids synthesized at 0.5 and 1.5 GPa. Not only the dimers but also soluble heavier oligomers and insoluble polymers formed through more extensive polymerization. The major reaction mechanism of 1,5-Nap was common to both the 0.5 and 1.5 GPa experiments, although the required reaction temperature increased with increasing pressure and aromatic rings preferentially remained at the higher pressure.