Vibrational analysis of urea
Vibrational analysis of urea
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DOI：
10.1021/jp984190z
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发表时间：
1999-06-17
影响因子：
2.9
通讯作者：
Van Alsenoy, C
中科院分区：
文献类型：
--
作者：
Keuleers, A;Desseyn, HO;Van Alsenoy, C
虽然已经做了大量的工作，对尿素的振动分析，仍然存在一些矛盾和不确定性，主要是由于结晶尿素的振动光谱的解释的力场计算的基础上孤立的尿素，而不是尿素在其晶体相。我们已经表明，这种方法是不允许的尿素的情况下。通过在室温和-196 ℃下测量尿素的八种同位素异构体的固态红外光谱、在室温和-120 ℃下测量尿素-水溶液的拉曼光谱来解释尿素的振动光谱。还使用了我们最近发表的关于孤立的尿素和尿素晶体结构的文章中的力场计算，在Hartree-Fock水平上使用6-31++G** 基组。我们还表明，使用“金刚石砧室”的高压测量是没有用的，通过执行振动分析。
Although a lot of work has been done on the vibrational analysis of urea, there still remain some contradictions and uncertainties, mainly due to interpretation of the vibrational spectrum of crystalline urea based on force field calculations on isolated urea instead of on urea in its crystal phase. We have shown that this approach is not allowed in the case of urea. The vibrational spectrum of urea was interpreted by measuring the solid state infrared spectra of eight isotopomers of urea at room temperature and at -196 degrees C, and Raman spectra at room temperature and at -120 degrees C, and of a urea-water solution. Force field calculations from our recently published article on isolated urea and on urea in its crystal structure, at the Hartree-Fock level with a 6-31++G** basis set, were also used. We have also shown that high-pressure measurements using a "diamond anvil cell" are not useful by performing a vibrational analysis.