The infrared spectra of NH3⋅H2O and ND3⋅D2O at 100 K
The infrared spectra of NH3⋅H2O and ND3⋅D2O at 100 K
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NH3⋅H2O 和 ND3⋅D2O 在 100 K 时的红外光谱
DOI：
10.1063/1.449430
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发表时间：
1985
影响因子：
4.4
通讯作者：
M. Shehata
中科院分区：
文献类型：
--
作者：
J. Bertie;M. Shehata
首次报道了ND3⋅D2O和NH3⋅H2O或ND3⋅D2O中氢、氘杂质在100 K下的红外光谱。他们的解释是由P212121， D42晶体中重原子几乎共面引起的D2h伪对称所辅助的。没有观察到氢原子可能无序的证据。定向气体模型计算给出了分子振动的单位胞成分的近似相对强度。ν3和ν4的位点分裂和相关分裂是相似的；在D2下预测的6个单元胞成分被观测到3个，其中3个成分被计算为具有接近零的强度。氨ν2的对称变形产生了两个强度显著的单元胞模式，NH3和ND3的间距分别为37 cm−1和23 cm−1。ν2的同位素频率比低于其他任何模式，因此这种大的分裂一定是由于分子间耦合，可能是起源的跃迁偶极子。
The infrared spectra of ND3⋅D2O and hydrogen or deuterium impurity in NH3⋅H2O or ND3⋅D2O at 100 K are reported for the first time. Their interpretation is aided by a D2h pseudosymmetry caused by the heavy atoms being nearly coplanar in the P212121, D42, crystal. No evidence of the possible disorder of the hydrogen atoms is observed. Oriented gas model calculations gave the approximate relative intensities of the unit cell components of the molecular vibrations. The site splitting and correlation splitting are comparable for ν3 and, probably, ν4 of ammonia; three unit cell components are observed instead of the six predicted under D2, three components being calculated to have near‐zero intensity. The symmetric deformation of ammonia, ν2, yields two unit cell modes with significant intensity, separated by 37 cm−1 for NH3 and 23 cm−1 for ND3. The isotope frequency ratio for ν2 is lower thanfor any other mode, so this large splitting must be due to intermolecular coupling, probably transition dipolar in origi...