Structures, energies, and spectra of aqua-silver (I) complexes

Abstract

Owing to the utility of redox phenomena of silver in many chemical systems, it is important to understand the coordination chemistry of Ag+ ion and hence the hydration structure. The lowest-energy conformations of Ag+(H2O)1–6 are sensitive to the calculation method employed. The coordination number (Nc) of Ag+(H2O)n is predicted to be 2 for n=2–6 at the density functional theory level, while the Nc for n=3–5 is 3, and that for n=6 is 4 at the second-order Møller–Plesset perturbation level. Further accurate analysis based on coupled-cluster singles and doubles theory with perturbative corrections for triple excitations agrees with the MP2 results except that Nc of 4 is also as competitive as Nc of 3 for n=5. To identify the correct Nc, it would be useful to facilitate the IR experimental characterization. We thus provide the OH spectra for various possible structures. It is interesting to note that the hydration chemistry of Ag+ ion is somewhat different from that of alkali metal ions.

Hydrated copper and gold monovalent cations: Ab initio study

“…19 The relativistic effective core potentials ͑RECP͒ including contracted ͓6s5p3d1f͔ and ͓7s5p4d1f͔ basis sets were used for Cu + and Au + ions. 20,24,26 The relativistic effect is known to be very large in gold.…”

“…23 Despite very few studies on hydrated heavy metal ions, there are some interesting studies on the hydration energies of transition metal ions. [19][20][21][22] In particular, experimental hydration and solvation energies and coordination numbers ͑CN͒ of hydrated copper and silver cation clusters have been reported. [5][6][7][8] The noble monovalent cations ͑Cu, Ag, and Au͒ have characteristic electronic properties with high electron affinity ͑EA͒.…”

“…On the other hand, we have studied monohydrated to hexahydrated silver cations, focusing on the changes of various thermodynamic quantities, spectra, and structural and coordination chemistry of multiply hydrated systems with respect to the hydration number. 19 This will provide the right answer for the coordination numbers of copper and gold cations by hydration. Thus, for the comparison of these hydrated clusters with the hydrated silver cation clusters, we here investigate monohydrated to hexahydrated copper and gold cations, focusing on the same subjects.…”

“…[13][14][15][16][17][18][19][20][21][22] Their characteristic coordination reflects the intrinsic properties of ions. It is of importance to investigate the hydration structure of transition metal ions which can be self-synthesized into self-assembled nanostructures upon reduction.…”

Understanding Clusters toward the Design of Functional Molecules and Nanomaterials

“…1). [71][72][73][74][75][76][77][78][79][80][81][82][83] On the other hand, in the anion water clusters the contribution of electrostatic interactions is less effective because they have a lower ratio of charge to radius than isoelectronic cations, while the polarization effect becomes significant. In anion-water clusters, [84][85][86][87][88][89][90][91][92][93] the anionwater dipole interaction is suppressed, and the inter-water Hbonding interactions around the anion become important.…”