Direct Crystallographic Observation of CO2 Captured in Zig Zag Channels of a Copper(I) Metal-Organic Framework

Reece G Miller; Mark R Warren; David R Allan; Sally Brooker

doi:10.1021/acs.inorgchem.0c00471

Direct Crystallographic Observation of CO₂ Captured in Zig Zag Channels of a Copper(I) Metal-Organic Framework

Inorg Chem. 2020 May 4;59(9):6376-6381. doi: 10.1021/acs.inorgchem.0c00471. Epub 2020 Apr 16.

Authors

Reece G Miller¹, Mark R Warren², David R Allan², Sally Brooker¹

Affiliations

¹ Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
² Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0QX, United Kingdom.

PMID: 32297741
DOI: 10.1021/acs.inorgchem.0c00471

Abstract

Single crystal X-ray diffraction has been used to study the CO₂ absorption sites in a microporous Cu-MOF, [Cu^I₂(py-pzpypz)₂(μ-CN)₂]_n (1) (where py-pzpypz = 4-(4-pyridyl)-2,5-dipyrazyl-pyridine), which features zigzag-shaped channels, at a range of CO₂ pressures (1, 5, and 10 bar) and at two temperatures (240 and 298 K). Unlike the acetonitrile molecules in the as-synthesized MOF, 1·MeCN, the CO₂ molecules in 1·nCO₂ (n = 0.8, 0.7, 0.45) are preferentially centered on the vertices of each zig and zag, which allows for weak (azine) C-H···OCO interactions with the H atoms on the electron-deficient pyrazine and pyridine rings of the MOF.