Issue 45, 2013

Bifunctional pyrazolate–carboxylate ligands for isoreticular cobalt and zinc MOF-5 analogs with magnetic analysis of the {Co44-O)} node

Abstract

The ditopic ligands 3,5-dimethyl-pyrazolate-4-carboxylate, Me2pzCO2, and 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoate, Me2pzC6H4CO2, combine a pyrazolate and carboxylate functionality in axial orientation and lead to porous cobalt or zinc azolate–carboxylate frameworks that have the same cubic pcu-a topology and {M44-O)} nodes (M = Co, Zn) as MOF-5 and other IRMOFs. The microporous networks [M44-O)(Me2pzCO2)3] (M = Co, Zn) with the short linker exhibit a solvent-induced gate effect, evidenced by gas desorption hysteresis due to small pore apertures of 2.8 Å diameter together with small amounts of high-boiling solvent remaining in the activated samples. For [Co44-O)(Me2pzCO2)3], the low-pressure H2 storage capacity (1.7 wt%, 1 bar , 77 K) is higher than for MOF-5, and the CO2 uptake of 20.8 wt% puts it among the top MOFs for low-pressure CO2 sorption even though the BET surface is less than 1000 m2 g−1. The analysis of the magnetic properties of [Co44-O)(Me2pzCO2)3] takes into account the distribution of tetrahedra resulting from the disorder of the pyrazolate–carboxylate linker. An antiferromagnetic coupling observed for [Co44-O)(Me2pzCO2)3] arises from the interactions of the cobalt(II) ions through the combined μ4-O + synsyn carboxylate and μ4-O + pyrazolate bridges.

Graphical abstract: Bifunctional pyrazolate–carboxylate ligands for isoreticular cobalt and zinc MOF-5 analogs with magnetic analysis of the {Co4(μ4-O)} node

Supplementary files

Article information

Article type
Paper
Submitted
18 Jūl. 2013
Accepted
16 Aug. 2013
First published
19 Aug. 2013

CrystEngComm, 2013,15, 9757-9768

Bifunctional pyrazolate–carboxylate ligands for isoreticular cobalt and zinc MOF-5 analogs with magnetic analysis of the {Co44-O)} node

C. Heering, I. Boldog, V. Vasylyeva, J. Sanchiz and C. Janiak, CrystEngComm, 2013, 15, 9757 DOI: 10.1039/C3CE41426D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements