Compositional control of pore geometry in multivariate metal-organic frameworks: an experimental and computational study

Thumbnail Image
c5dt04045k.pdf(2.44 MB)
Published version
c5dt04045k1.pdf(2.13 MB)
Supplementary file
Cadman, Laura K.
Bristow, Jessica K.
Stubbs, Naomi E.
Tiana, Davide
Mahon, Mary F.
Walsh, Aron
Burrows, Andrew D.
Journal Title
Journal ISSN
Volume Title
Royal Society of Chemistry (RSC)
Published Version
Research Projects
Organizational Units
Journal Issue
A new approach is reported for tailoring the pore geometry in five series of multivariate metal-organic frameworks (MOFs) based on the structure [Zn-2(bdc)(2)(dabco)] (bdc = 1,4-benzenedicarboxylate, dabco = 1,8-diazabicyclooctane), DMOF-1. A doping procedure has been adopted to form series of MOFs containing varying linker ratios. The series under investigation are [Zn-2(bdc)(2-x)(bdc-Br)(x)(dabco)]center dot nDMF 1 (bdc-Br = 2-bromo-1,4-benzenedicarboxylate), [Zn-2(bdc)(2-x)(bdc-I)(x)(dabco)]center dot nDMF 2 (bdc-I = 2-iodo-1,4-benzenedicarboxylate), [Zn-2(bdc)(2-x)(bdc-NO2)(x)(dabco)]center dot nDMF 3 (bdc-NO2 = 2-nitro-1,4-benzenedicarboxylate), [Zn-2(bdc)(2-x)(bdc-NH2)(x)(dabco)]center dot nDMF 4 (bdc-NH2 = 2-amino-1,4-benzenedicarboxylate) and [Zn-2(bdc-Br)(2-x)(bdc-I)(x)(dabco)] nDMF 5. Series 1-3 demonstrate a functionality-dependent pore geometry transition from the square, open pores of DMOF-1 to rhomboidal, narrow pores with increasing proportion of the 2-substituted bdc linker, with the rhomboidal-pore MOFs also showing a temperature-dependent phase change. In contrast, all members of series 4 and 5 have uniform pore geometries. In series 4 this is a square pore topology, whilst series 5 exhibits the rhomboidal pore form. Computational analyses reveal that the pore size and shape in systems 1 and 2 is altered through non-covalent interactions between the organic linkers within the framework, and that this can be controlled by the ligand functionality and ratio. This approach affords the potential to tailor pore geometry and shape within MOFs through judicious choice of ligand ratios.
Porous coordination polymers , Minimum energy paths , Elastic band method , Crystal-structures , Hydrogen storage , Saddle-points , Program , Adsorption , Stability
Cadman, L. K., Bristow, J. K., Stubbs, N. E., Tiana, D., Mahon, M. F., Walsh, A. and Burrows, A. D. (2016) 'Compositional control of pore geometry in multivariate metal-organic frameworks: an experimental and computational study', Dalton Transactions, 45(10), pp. 4316-4326. doi: 10.1039/c5dt04045k