Phosphomolybdate assembly as a low-cost catalyst for the reduction of toxic Cr(vi) in aqueous solution.

Highly reduced phosphomolybdate hybrid compounds have been hydrothermally prepared and structurally defined. X-ray single-crystal analysis revealed that these phosphomolybdates had the following formulae: (Hbpp){Fe[MoO(OH)(HPO)(HPO)]}·11HO (1), (Hbpp){Zn[MoO(OH)(HPO)(HPO)]}·11HO (2), and (Hbpp){Mn[MoO(OH)(HPO)(HPO)]}·2HO (3) (bpp = 1,3-bi(4-pyridyl)propane). In the inorganic moiety, all Mo centers are in the +5 reduced form, representing a unique, fully reduced cluster in the polyanionic family.

The protonated 2-halogenated imidazolium cation as the noncovalent interaction donor: the σ-hole and π-hole interactions.

The σ-hole and π-hole of the protonated 2-halogenated imidazolium cation (XCHN; X = F, Cl, Br, I) were investigated and analyzed. The monomers of (CH)SiY(Y=F, Cl, Br, I), considered as the Lewis base, were combined with the σ-hole and π-hole of XCHN to form the σ-hole and π-hole interactions in the bimolecular complexes (CH)SiY · · · XCHN and (CH)SiY · · · C(X)HN(X/Y=F, Cl, Br, I), respectively. For both the σ-hole and π-hole interactions, the equilibrium geometries of complexes show regular changes according to the sequence of heavy sequence of the noncovalent interaction acceptors and donors.