Dokter Adriaan M, Petersen Christian, Woutersen Sander, Bakker Huib J
FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
J Chem Phys. 2008 Jan 28;128(4):044509. doi: 10.1063/1.2826376.
The ultrafast vibrational dynamics of HDO:D(2)O ice at 180 K in anionic reverse micelles is studied by midinfrared femtosecond pump-probe spectroscopy. Solutions containing reverse micelles are cooled to low temperatures by a fast-freezing procedure. The heating dynamics of the micellar solutions is studied to characterize the micellar structure. Small reverse micelles with a water content up to approximately 150 water molecules contain an amorphous form of ice that shows remarkably different vibrational dynamics compared to bulk hexagonal ice. The micellar amorphous ice has a much longer vibrational lifetime than bulk hexagonal ice and micellar liquid water. The vibrational lifetime is observed to increase linearly from 0.7 to 4 ps with the resonance frequency ranging from 3100 to 3500 cm(-1). From the pump dependence of the vibrational relaxation the homogeneous linewidth of the amorphous ice is determined (55+/-5 cm(-1)).
利用中红外飞秒泵浦 - 探测光谱研究了180K下阴离子反胶束中HDO:D₂O冰的超快振动动力学。通过快速冷冻程序将含有反胶束的溶液冷却至低温。研究了胶束溶液的加热动力学以表征胶束结构。含水量高达约150个水分子的小反胶束含有一种非晶态冰，其振动动力学与块状六方冰相比有显著差异。胶束非晶态冰的振动寿命比块状六方冰和胶束液态水长得多。观察到振动寿命随着共振频率从3100至3500cm⁻¹线性增加，从0.7ps增加到4ps。根据振动弛豫的泵浦依赖性确定了非晶态冰的均匀线宽（55±5cm⁻¹）。
