氮气笼型水合物的激光拉曼光谱

在253K和16MPa的压力下，于实验室内合成了氮气水合物，用显微共焦拉曼光谱对其N-N和O-H键伸缩振动的光谱特征进行了研究．结果表明，氮气水合物中的N-N和O—H键的拉曼峰分别为2322．4和3092．1cm^-1，与天然的空气水合物中的数据十分接近．另外，还测定了液氮和溶解于水中的氮分子中N—N键的拉曼峰值，分别为2326．6和2325．0cm^-1．氮气笼型水合物分解的拉曼谱图表明，氮分子同时进入水合物的大笼和小笼中，但由于氮分子在大、小笼中的环境氛围十分接近，其拉曼位移相差不大，故拉曼谱图只能显示N—N键伸缩振动一个峰．

Raman Spectroscopy of Nitrogen Clathrate Hydrates

Nitrogen hydrate samples were synthesized using liquid nitrogen and powder ice at 16 MPa and 253 K. Confocal laser Raman spectroscopy was used to investigate the characteristics of nitrogen clathrate hydrates. The results show that the Raman peaks of N-N and O-H stretching vibration in nitrogen hydrates are observed at 2322.4 and 3092.1 cm^-1, respectively, which are very similar to those in natural air clathrate hydrates. For comparison, we measured the Raman peaks of N-N stretching vibration both in liquid nitrogen and nitrogen molecules saturated water, which appear at 2326.6 and 2325.0 cm^-1, respectively. The Raman spectroscopic observations on the dissociation process suggest that nitrogen molecules occupy both the large and small cages in nitrogen clathrate hydrates. However, only one Raman peak is observed for N N stretching vibration because the difference of the environment of nitrogen molecules between large and small cages is too small to be differentiated by Raman spectroscopy.