Investigation of zeolitic imidazolate frameworks using 13C and 15N solid-state NMR spectroscopy

Scott Sneddon, Juergen Kahr, Angelica F. Orsi, David J. Price, Daniel M. Dawson, Paul A. Wright, Sharon E. Ashbrook

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)
2 Downloads (Pure)

Abstract

Zeolitic imidazolate frameworks (ZIFs) are a subclass of metal-organic frameworks (MOFs) with extended three-dimensional networks of transition metal nodes (bridged by rigid imidazolate linkers), with potential applications in gas storage and separation, sensing and controlled delivery of drug molecules. Here, we investigate the use of 13C and 15N solid-state NMR spectroscopy to characterise the local structure and disorder in a variety of single- and dual-linker ZIFs. In most cases, a combination of a basic knowledge of chemical shifts typically observed in solution-state NMR spectroscopy and the use of dipolar dephasing NMR experiments to reveal information about quaternary carbon species are combined to enable spectral assignment. Accurate measurement of the anisotropic components of the chemical shift provided additional information to characterise the local environment and the possibility of trying to understand the relationships between NMR parameters and both local and long-range structure. First-principles calculations on some of the simpler, ordered ZIFs were possible, and provided support for the spectral assignments, while comparison of these model systems to more disordered ZIFs aided interpretation of the more complex spectra obtained. It is shown that 13C and 15N NMR are sufficiently sensitive to detect small changes in the local environment, e.g., functionalisation of the linker, crystallographic inequivalence and changes to the framework topology, while the relative proportion of each linker present can be obtained by comparing relative intensities of resonances corresponding to chemically-similar species in cross polarisation experiments with short contact times. Therefore, multinuclear NMR spectroscopy, and in particular the measurement of both isotropic and anisotropic parameters, offers a useful tool for the structural study of ordered and, in particular, disordered ZIFs.
Original languageEnglish
Pages (from-to)54-64
Number of pages11
JournalSolid State Nuclear Magnetic Resonance
Volume87
Early online date9 Sept 2017
DOIs
Publication statusPublished - Oct 2017

Keywords

  • Zeolitic imidazolate frameworks
  • Microporous materials
  • ZIFs
  • DFT
  • Solid-state NMR
  • 13C NMR
  • 15N NMR
  • CSA-amplified PASS

Fingerprint

Dive into the research topics of 'Investigation of zeolitic imidazolate frameworks using 13C and 15N solid-state NMR spectroscopy'. Together they form a unique fingerprint.

Cite this