摘要
The molecular structure of liquid water has been an outstanding issue for many years. The identification of free -OH holds the key in differentiating structure models for liquid water. By analyzing the relative changes of the intensity and depolarization ratio in temperature dependent Raman spectra, the occurrence of free -OH in liquid water is unambiguously de- termined. Furthermore, upon the increase of temperature from 5 ~C to 85 ~C, the structure of liquid water undergoes significant change, but the relative proportion of free -OH is con- siderably small and remains almost unchanged. This implies that the breaking of hydrogen bond from the tetrahedral structure prefers to The energetic favoring of the structural change experiments. occur at the site of the hydrogen acceptor. for liquid water is thus clearly revealed from
基金
This work is supported by the National Key Basic Research Special Foundation （No.2010CB923300）, the National Natural Science Foundation of China （No.20925311, No.91127042, and No.21103158）, and the GSran Gustafsson Foundation for Research in Natural Sciences and Medicine.
