O NMR Spectroscopy Reveals CO Speciation and Dynamics in Hydroxide-based Carbon Capture Materials.

Carbon dioxide capture technologies are set to play a vital role in mitigating the current climate crisis. Solid-state O NMR spectroscopy can provide key mechanistic insights that are crucial to effective sorbent development. In this work, we present the fundamental aspects and complexities for the study of hydroxide-based CO capture systems by O NMR.

Comparative study of metal-organic frameworks synthesized imide condensation and coordination assembly.

A series of metal-organic frameworks (1-XDI) have been synthesized by imide condensation reactions between an amine-functionalized pentanuclear zinc cluster, ZnCl(bt-NH), (bt-NH = 5-aminobenzotriazolate), and organic dianhydrides (pyromellitic dianhydride (PMDA), naphthalenetetracarboxylic dianhydride (NDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (HFIPA)). The properties of the 1-XDI MOFs have been compared with analogues (2-XDI) prepared using traditional coordination assembly. The resulting materials have been characterized by ATR-IR spectroscopy, acid-digested H NMR spectroscopy, elemental analysis, and gas adsorption measurements.

Facile immobilization of PNP-Pd pincer complexes in MFU-4-OH and the effects of guest loading on Lewis acid catalytic activity.

A palladium diphosphine pincer complex H(PNP-PdI) has been encapsulated in the benzotriazolate metal-organic framework MFU-4-OH ([Zn(OH)(btdd)], btdd = bis(1,2,3-triazolo)dibenzodioxin), and the resulting materials were investigated as Lewis acid catalysts for cyclization of citronellal to isopulegol. Rapid catalyst immobilization is facilitated by a Brønsted acid-base reaction between the H(PNP-PdI) benzoic acid substituents and Zn-OH groups at the framework nodes. Catalyst loading can be controlled up to a maximum of 0.