Cation behavior at an artificial cell interface: binding distinguished by ion hydration energetics and size

Abstract

The unique molybdenum oxide-based nucleophilic porous capsule/artificial cell [{(MoVI)MoVI5O21(H2O)6}12{MoV2O4(SO4)30}]72-, according to an X-ray crystallographic study, traps [Al(H2O)6]3+ complexes above the pores while interacting with the latter via hydrogen bonds; this is supported by 27Al NMR studies of the interaction of the capsule with hydrated Al3+ cations in aqueous solution.

Unprecedented and Differently Applicable Pentagonal Units in a Dynamic Library: A Keplerate of the Type {(W)W5}12{Mo2}30

“…Most spectroscopic measurements were performed on deaerated solutions, which, however, did not appear to be especially sensitive to oxidation. Raman and 1 H and 13 C NMR spectroscopy therefore demonstrate the stability of 1 a in aqueous solutions, a feature shared with its {Mo 132 } counterpart 19…”

“…(The same holds for the {Mo 132 }‐type species with different ligands 1. 19) Though the spectrum is, as expected, similar to that of its {Mo 132 } counterpart, 1, 7c significant (but expected) differences arising from a change in the MO bond polarizability are observed: the line at 976 cm −1 , which is assigned to the ν (WO term ) A g ‐type vibration (assuming I h symmetry), is much more intense than the corresponding line of the ν (MoO term ) vibration of {Mo 132 }, in agreement with the higher bond polarizability of the terminal WO bond (effect not caused by the different excitation lines). ν (WO term ) at 976 cm −1 also occurs at higher wavenumbers than the corresponding vibrations of {Mo 132 } (the weak band at ca.…”

Unprecedented and Differently Applicable Pentagonal Units in a Dynamic Library: A Keplerate of the Type {(W)W5}12{Mo2}30

“…(The same holds for the {Mo 132 }-type species with different ligands. [1,19] ) Though the spectrum is, as expected, similar to that of its {Mo 132 } counterpart, [1, 7c] significant (but expected) differences arising from a change in the M=O bond polarizability are observed: the line at 976 cm À1 , which is assigned to the n(W=O term ) A g -type vibration (assuming I h symmetry), is much more intense than the corresponding line of the n(Mo = O term ) vibration of {Mo 132 }, in agreement with the higher bond polarizability of the terminal W = O bond (effect not caused by the different excitation lines). n(W=O term ) at 976 cm À1 also occurs at higher wavenumbers than the corresponding vibrations of {Mo 132 } (the weak band at ca.…”

“…Raman and 1 H and 13 C NMR spectroscopy therefore demonstrate the stability of 1 a in aqueous solutions, a feature shared with its {Mo 132 } counterpart. [19] Detailed knowledge of the properties of the structurally well-defined nanosurfaces of the present type of metal oxide based system is of interest for several aspects of materials science. In this context, we have studied solution properties of the new cluster 1 a and compared them to those of the molybdenum analogue {Mo 132 }.…”

Tracking “Apolar” NMe4+ Ions within Two Polyoxothiomolybdates that Have the Same Pores: Smaller Clathrate and Larger Highly Porous Clusters in Action

“…[27] With regard to the unusual "behavior" of the predominantly apolar NMe 4 + cations in water and their interactions with the Keplerate pores, there exists a related competition. [28] Several studies with different methods have been published (see Refs. [29,30], and literature cited therein) that focus on understanding aspects of the hydrophobic effect on the basis of NMe 4 + (see also the title of Ref.…”