Dynamic environment at the Zr₆ oxo cluster surface is key for the catalytic formation of amide bonds

Abstract

Zirconium compounds are an attractive alternative to costly, low abundant metals for the development of inexpensive, readily available, and robust catalysts. The air and moisture stable Zr oxo clusters such...

Reticular Chemistry of the Fcu‐Type Gd(III)‐Doped Metal–Organic Framework for T1‐Weighted Magnetic Resonance Imaging

“…To further examine the advantage of Gd(III)-doped Zr-oxo cluster in nano-aggregate state underlying the fcu-type framework over that of a discrete molecular cluster for relaxation, molecular [Zr 6 (OH) 4 O 4 (OMc) 12 ] (OMc = methacrylate) was chosen as a representative cluster because of the same Zr-oxo species (Figure 5a). [47,48] Consequently, the Gd(III)-doped molecular cluster (Zr 3 Gd 3 for short) was synthesized and characterized (Figures S19 and S20, Table S3, Supporting Information). In vitro MRI study gave its r 1 value only of 2.67 mM −1 s −1 .…”

Reactivity of metal–oxo clusters towards biomolecules: from discrete polyoxometalates to metal–organic frameworks

“…1(f) and 6(b)). 127,128 These findings highlight the potential of both M–POMs and neutral Zr 4+ clusters as highly promising water-tolerant catalysts for peptide bond formation that do not require harsh conditions or the use of additives. 126–129…”

“…126 Zr 4+ and Hf 4+ M–POMs have also been shown to catalyze direct intermolecular amide bond formation in different organic solvents. 127,128 The catalytic activity of M–POMs towards both intra- and intermolecular peptide bond formation was found to depend on the POM structure and number of embedded metal centers. 126,129 Additionally, neutral hexanuclear and dodecanuclear Zr 4+ clusters ([Zr 6 (OH) 4 O 4 (OMc) 12 ] where Mc = methacrylate and [Zr 6 (OH) 4 O 4 (OAcr) 12 ] 2 where Acr = acrylate) have also shown promising catalytic activity towards direct intermolecular amide bond formation (Fig.…”

Green, Safe, and Reliable Synthesis of Bimetallic MOF‐808 Nanozymes With Enhanced Aqueous Stability and Reactivity for Biological Applications

“…Formation of the condensation by-product cyclic glycylglycine (cGG) was also observed over the course of the reaction, in agreement with our previous reports on Zr-based clusters and Zr-MOFs catalyzed peptide bond formation. [58][59][60][61][62] This bi-product was fully hydrolyzed to linear GG and G sequentially, thus not interfering with the final outcome of the reaction. A control experiment monitoring GG hydrolysis after removal of the MOF via centrifugation ensured hydrolysis was due only to the presence of the MOF catalyst (Figure S21, Supporting Information).…”