Polarization IR spectra of hydrogen bonded pyrazole crystals: self-organization effects in proton and deuteron mixture systems. Long-range H/D isotopic effects
作者:Henryk T Flakus、Aleksandra Machelska
DOI:10.1016/s1386-1425(01)00553-4
日期:2002.2
their polarization properties with the decrease of temperature. These effects were ascribed to some temperature-induced conformational changes in the hydrogen bond lattices. The studies reported allowed the finding of new kind of isotopic effects H/D in the open-chain hydrogen bond systems, i.e. the self-organization effects. It was found that the spectrally active aggregates of hydrogen bonds remain unchanged
本文涉及固态吡唑H1345以及其H1D345,D1H345和D1345氘衍生物的偏振红外光谱的实验研究。在298和77 K的温度下对vN-H和vN-D频段的频率范围进行了测量。发现随着温度的降低,光谱会强烈改变其强度分布和偏振特性。这些影响归因于氢键晶格中一些温度诱导的构象变化。报道的研究允许在开链氢键系统中发现新的同位素效应H / D,即自组织效应。已发现,尽管同位素H / D交换速率增加,氢键的光谱活性聚集体仍保持不变。通过对同位素稀释的晶体样品测量的残留极化vN-H和vN-D带性质的分析支持了这一说法。对四种氢同位素衍生物晶体的能带形状的分析证明存在另一种H / D同位素效应,即长程同位素效应。这取决于吡唑环氢原子对vN-H和vN-D带宽以及带精细结构的影响。