2024-03-28T16:56:20Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/197332016-02-16T06:05:19Zcom_10261_31com_10261_3com_10261_98col_10261_284col_10261_351
00925njm 22002777a 4500
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Chaboy, Jesús
author
Muñoz-Páez, Adela
author
Merkling, Patrick J.
author
Sánchez Marcos, Enrique
author
2006-02
The long elusive structure of Cu(II) hydrate in aqueous solutions, classically described as a Jahn-Teller distorted octahedron and recently proposed to be a fivefold coordination structure [Pasquarello et al., Science 291, 856 (2001)], has been probed with x-ray-absorption spectroscopy by performing a combined theoretical and experimental analysis. Two absorption channels were needed to obtain a proper reproduction of the x-ray-absorption near-edge structure (XANES) region spectrum, as already observed in other Cu(II) complexes [Chaboy et al., Phys. Rev. B 71, 134208 (2005)]. The extended x-ray-absorption fine-structure (EXAFS) spectrum was analyzed as well within this approach. Quite good reproductions of both XANES and EXAFS spectra were attained for several distorted and undistorted structures previously proposed. Nevertheless, there is not a clearly preferred structure among those including four-, five-, and sixfold coordinated Cu(II) ions. Taking into account our results, as well as many more from several other authors using different techniques, the picture of a distorted octahedron for the Cu(II) hexahydrate in aqueous solution, paradigm of the Jahn-Teller effect, is no longer supported. In solution a dynamical view where the different structures exchange among themselves is the picture that better suits the results presented here.
Journal of Chemical Physics 124(6): 064509 (2006)
0021-9606
http://hdl.handle.net/10261/19733
10.1063/1.2165189
Copper compounds
Jahn-Teller effect
Solvation
XANES
EXAFS
Liquid structure
The hydration of Cu2+: Can the Jahn-Teller effect be detected in liquid solution?