Monohydrate of argentous fluoride: H2O?AgF characterised by rotational spectroscopy and ab initio calculations
Monohydrate of argentous fluoride: H2O?AgF characterised by rotational spectroscopy and ab initio calculations
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氟化亚银一水合物：H2O?AgF 通过旋转光谱和从头算计算进行表征
DOI：
10.1016/j.jms.2011.03.004
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发表时间：
2011
影响因子：
1.4
通讯作者：
Stephens S
中科院分区：
文献类型：
--
作者：
Stephens S
测量并分析了 H2O⋯AgF 八种同位素体的基本振动态的纯旋转光谱，以确定旋转和离心畸变常数。根据实验数据确定的分子结构和光谱参数与 CCSD(T) 级别的计算结果一起呈现。实验和理论都与平衡时非平面的结构一致。在确定的r0几何结构中，重原子是共线的，而水分子的局部C2轴与重原子定义的轴以一定角度相交，ψ= 41.9(11)°。因此平衡几何具有 Cs 对称性。然而，在零点状态下，分子实际上是平面的，在两个等效结构之间经历快速反转，其中 phi 具有相等的大小但符号相反。从头计算证实，这种反转的时间尺度至少比分子在最低旋转能级下的旋转快一个数量级。使用简单的规则来合理化分子几何形状，这些规则调用复合物内的静电相互作用。
Pure rotational spectra of the ground vibrational states of eight isotopologues of H2O⋯AgF have been measured and analysed to determine rotational and centrifugal distortion constants. The molecular structure and spectroscopic parameters determined from the experimental data are presented alongside the results of calculations at the CCSD(T) level. Both experiment and theory are consistent with structures that are non-planar at equilibrium. In the determinedr0geometry, the heavy atoms are collinear while the localC2axis of the water molecule intersects the axis defined by the heavy atoms at an angle,ϕ= 41.9(11)°. The equilibrium geometry thus hasCssymmetry. In the zero-point state, however, the molecule is effectively planar, undergoing rapid inversion between two equivalent structures whereϕhas equal magnitude but opposite sign. The ab initio calculations confirm that the timescale of this inversion is at least an order of magnitude faster than that of rotation of the molecule in the lowest rotational energy levels. The molecular geometries are rationalized using simple rules that invoke the electrostatic interactions within the complexes.