Chen Chen, Huang Congcong, Waluyo Iradwikanari, Weiss Thomas, Pettersson Lars G M, Nilsson Anders
Department of Chemistry, Stanford University, Stanford, California 94305, USA.
Phys Chem Chem Phys. 2015 Apr 7;17(13):8427-30. doi: 10.1039/c4cp04759a. Epub 2015 Jan 28.
Using small-angle X-ray scattering (SAXS), we obtained direct experimental evidence on the structure of hydrated polyatomic anions, with hydration effects starkly different from those of cations (J. Chem. Phys., 2011, 134, 064513). We propose that the size and charge density of the naked ions do not sufficiently account for the differences in the SAXS curves. For cations, the ion-ion contribution gives a prominent first-order diffraction peak, whereas for anions, the low-Q enhancement in the SAXS curves indicates density inhomogeneities as a result of ion-water interactions.
利用小角X射线散射（SAXS），我们获得了关于水合多原子阴离子结构的直接实验证据，其水合效应与阳离子的水合效应截然不同（《化学物理杂志》，2011年，第134卷，064513）。我们认为，裸离子的大小和电荷密度不足以解释SAXS曲线的差异。对于阳离子，离子-离子相互作用产生一个突出的一级衍射峰，而对于阴离子，SAXS曲线中的低Q增强表明离子-水相互作用导致的密度不均匀性。
