Cruzan J D, Braly L B, Liu K, Brown M G, Loeser J G, Saykally R J
Department of Chemistry, University of California at Berkeley 94720, USA.
Science. 1996 Jan 5;271(5245):59-62. doi: 10.1126/science.271.5245.59.
Measurement of the far-infrared vibration-rotation tunneling spectrum of the perdeuterated water tetramer is described. Precisely determined rotational constants and relative intensity measurements indicate a cyclic quasi-planar minimum energy structure, which is in agreement with recent ab initio calculations. The O-O separation deduced from the data indicates a rapid exponential convergence to the ordered bulk value with increasing cluster size. Observed quantum tunneling splittings are interpreted in terms of hydrogen bond rearrangements connecting two degenerate structures.
描述了全氘代水四聚体的远红外振动-转动隧穿光谱的测量。精确测定的转动常数和相对强度测量表明存在一种环状准平面最低能量结构，这与最近的从头算计算结果一致。从数据推导出的O-O间距表明，随着团簇尺寸的增加，它迅速指数收敛到有序的体相值。观察到的量子隧穿分裂是根据连接两个简并结构的氢键重排来解释的。
