计算机与应用化学
計算機與應用化學
계산궤여응용화학
COMPUTERS AND APPLIED CHEMISTRY
2013年
12期
1389-1392
,共4页
三聚氰胺%悬浊液%三聚氰酸二酰胺%红外光谱%分子模拟
三聚氰胺%懸濁液%三聚氰痠二酰胺%紅外光譜%分子模擬
삼취청알%현탁액%삼취청산이선알%홍외광보%분자모의
melamine%suspension%ammeline%infrared spectrum%molecular simulation
针对三聚氰胺在水中形成的悬浊液体系能呈现类胶体稳定性的实验现象，采用密度泛函方法在 B3LYP/6-311++G**水平上对三聚氰胺及其水解产物进行了量子化学计算，并将计算结果与红外光谱实验结果作比较。热力学计算结果表明，三聚氰酸二酰胺与相应酮式结构之间进行互变异构的ΔG为-41.62 kJ?mol-1，说明酮式结构更加稳定。红外光谱实验结果显示，三聚氰胺样品在2360 cm-1处有较明显的吸收峰，与三聚氰酸二酰胺酮式结构的计算结果比较吻合，因此三聚氰胺在水中发生初步水解生成三聚氰酸二酰胺酮式结构的可能性较大。通过分子振动频率分析与红外光谱实验的对比可知，三聚氰酸二酰胺酮式结构的二聚体在2300 cm-1附近的N-H键的伸缩振动吸收峰发生劈裂，吸收峰位红移约25 cm-1，表明二聚体之间形成了N-H···N氢键。可以推测，三聚氰酸二酰胺可以通过氢键连接形成聚集结构，最终导致三聚氰胺悬浊液能够稳定存在。这些研究结果为三聚氰胺-水体系的工业应用和深入探索提供了实验和理论的参考依据。
針對三聚氰胺在水中形成的懸濁液體繫能呈現類膠體穩定性的實驗現象，採用密度汎函方法在 B3LYP/6-311++G**水平上對三聚氰胺及其水解產物進行瞭量子化學計算，併將計算結果與紅外光譜實驗結果作比較。熱力學計算結果錶明，三聚氰痠二酰胺與相應酮式結構之間進行互變異構的ΔG為-41.62 kJ?mol-1，說明酮式結構更加穩定。紅外光譜實驗結果顯示，三聚氰胺樣品在2360 cm-1處有較明顯的吸收峰，與三聚氰痠二酰胺酮式結構的計算結果比較吻閤，因此三聚氰胺在水中髮生初步水解生成三聚氰痠二酰胺酮式結構的可能性較大。通過分子振動頻率分析與紅外光譜實驗的對比可知，三聚氰痠二酰胺酮式結構的二聚體在2300 cm-1附近的N-H鍵的伸縮振動吸收峰髮生劈裂，吸收峰位紅移約25 cm-1，錶明二聚體之間形成瞭N-H···N氫鍵。可以推測，三聚氰痠二酰胺可以通過氫鍵連接形成聚集結構，最終導緻三聚氰胺懸濁液能夠穩定存在。這些研究結果為三聚氰胺-水體繫的工業應用和深入探索提供瞭實驗和理論的參攷依據。
침대삼취청알재수중형성적현탁액체계능정현류효체은정성적실험현상，채용밀도범함방법재 B3LYP/6-311++G**수평상대삼취청알급기수해산물진행료양자화학계산，병장계산결과여홍외광보실험결과작비교。열역학계산결과표명，삼취청산이선알여상응동식결구지간진행호변이구적ΔG위-41.62 kJ?mol-1，설명동식결구경가은정。홍외광보실험결과현시，삼취청알양품재2360 cm-1처유교명현적흡수봉，여삼취청산이선알동식결구적계산결과비교문합，인차삼취청알재수중발생초보수해생성삼취청산이선알동식결구적가능성교대。통과분자진동빈솔분석여홍외광보실험적대비가지，삼취청산이선알동식결구적이취체재2300 cm-1부근적N-H건적신축진동흡수봉발생벽렬，흡수봉위홍이약25 cm-1，표명이취체지간형성료N-H···N경건。가이추측，삼취청산이선알가이통과경건련접형성취집결구，최종도치삼취청알현탁액능구은정존재。저사연구결과위삼취청알-수체계적공업응용화심입탐색제공료실험화이론적삼고의거。
In order to investigate the stability of the melamine-water suspension, theoretical calculation on melamine and its hydrolysate was carried out at B3LYP/6-311++G**level, and the solvent effect was explored by polarizable continuum model (PCM), assigning water as the solvent in consideration of the solvent effect. The melamine may be preliminarily hydrolyzed to form ammeline, and the Gibbs free energy change of the tautomerism from ammeline to its keto form is calculated to be -41.62 kJ?mol-1, which means the keto form is more stable. Meanwhile, the absorption peak of melamine powder at 2360 cm-1 obtained by infrared spectrums experiment is accordant with the quantum calculation result of the keto form of the ammeline. The coincident results suggest the primary hydrolysate of the melamine. Moreover, the absorption peak of stretching vibration of N-H bond in ammeline dimer splits, and the redshift of the peak is found to be about 25 cm-1, implying the formation of N-H···N hydrogen bond between the monomers. It can be speculated that the hydrolysate may be connected through hydrogen bonds to generate the aggregate structure, resulting in the stableness of the melamine suspension. And the structures of ammeline tetramer and multimer were also optimized at B3LYP/6-31G and PM6 level respectively. These conclusions can provide theoretical and experimental references for the industrial application and further research of melamine solution.
