Hansen K, Andersson P U, Uggerud E
Department of Physics, University of Gothenburg, SE-41296 Gothenburg, Sweden.
J Chem Phys. 2009 Sep 28;131(12):124303. doi: 10.1063/1.3230111.
Experimental mass abundance spectra are used to extract evaporative activation energies (dissociation energies) for protonated water clusters, (H(2)O)(N)H(+), and deprotonated water clusters, (H(2)O)(N)OH(-), in the size range up to hundred molecules. The inversion is achieved by application of the shell correction method adapted from nuclear physics to the abundance spectra. The well known abundance anomaly for protonated clusters which occurs for N=20-22 is found to have the characteristic behavior of a shell closing, whereas other apparent magic numbers are only prominent peaks in the abundance spectra because of the instability of the evaporative precursor. For the deprotonated clusters, we find a similar shell closing for N=55-56.
实验质量丰度谱用于提取质子化水团簇(H₂O)ₙH⁺和去质子化水团簇(H₂O)ₙOH⁻在分子数高达一百的尺寸范围内的蒸发活化能（解离能）。通过将核物理中采用的壳修正方法应用于丰度谱来实现反演。发现质子化团簇在N = 20 - 22时出现的众所周知的丰度异常具有壳闭合的特征行为，而其他明显的幻数只是由于蒸发前体的不稳定性而在丰度谱中表现为突出的峰。对于去质子化团簇，我们发现N = 55 - 56时存在类似的壳闭合。
