Picking up 30 CO₂ Molecules by a Porous Metal Oxide Capsule Based on the Same Number of Receptors

Abstract

30 receptors in waiting position: In the porous (pentagon)(12)(linker)(30)-type molybdenum oxide capsule (see picture), the 30 positively charged linkers (five unsaturated shown for illustration in green, the others contain CO(3)(2-) ligands) can act as receptors for neutral and negatively charged ligands. Bubbling CO(2) into the solution containing the acetate-type capsules leads to the upload of CO(2) based on 30 coordinated CO(3)(2-) ligands.

Light driven decarboxylative cross coupling of acrylic acid and iodobenzene using [Mo 132 ] type keplerate as a catalyst

“…Detailed study of this reaction has thrown some light on a plausible reaction mechanism. We logically predict that initially acrylic acid is attached on the surface of the polyoxometalate with carboxylic group as these clusters have available coordination sites (Mo=O t ) and we already know that these clusters are prone to attachment with carbonate, and related organic components [10,31,43,44]. Furthermore, Mo VI centers absorb UV-light to go to the excited state, which is a strong oxidizing agent.…”

Anions coordinating anions: analysis of the interaction between anionic Keplerate nanocapsules and their anionic ligands

“…33 Mo 132 has shown to be also capable of modifying the regioselectivity of the Huisgen reaction, 34 and very remarkably, to uptake CO 2 and transform it to carbonate. 25 The mechanism of this CO 2 hydration reaction is now well understood and is mediated by the linkers too. 35 Related to CO 2 uptake, Garai et al…”

Densely Packed Hydrophobic Clustering: Encapsulated Valerates Form a High‐Temperature‐Stable {Mo132} Capsule System

“…Indeed, competition experiments demonstrate that replacement of the acetate ligands by increasingly larger carboxylate ions is hampered by increased steric hindrance.F or example,t his process is approximately five times less favorable for valerate than for butyrate (see Figure S1 in the Supporting Information). On the other hand, the carbonate-type {Mo 132 }capsule 1a,which is moderately stable in aqueous solution only over al imited pH range,undergoes release of CO 2 upon acidification of the corresponding solution, [14] which leads to ah ighly reactive intermediate that is eager to entrap any ligand present. In the present case,e ncapsulation is further promoted by the tendency of valerate ions to aggregate through hydrophobic interactions with the capsule.…”

“…[17] Besides the signal due to dimethylammonium ions,t he 1 HNMR spectrum of 2 dissolved in D 2 O ( Figure 3) shows four sharp signals that reveal the presence of some "free" valerates together with four significantly broadened signals. Peak broadening is generally observed as ac onsequence of restricted mobility for any of the species,s uch as carboxylates [4,7,8,18] and carbonate [14] encapsulated within {Mo 132 }-type capsules.The presence of both internally bound and free valerates in aqueous solutions of 2 is further demonstrated by 1 HD OSY NMR spectroscopy (see Figure S4). …”