Jump to main content
Jump to site search

Issue 46, 2014
Previous Article Next Article

Porous macromolecular dihydropyridyl frameworks exhibiting catalytic and halochromic activity

Author affiliations

Abstract

New porous macromolecular frameworks (PMFs) have been designed and prepared by the condensation of dialdehydes with aminoacrylonitriles. Two porous materials were prepared by reacting 3,3′-benzene-1,4-diylbis(3-aminoprop-2-enenitrile) with benzene-1,4-dicarbaldehyde and biphenyl-4,4′-dicarbaldehyde to give PMF-NOTT-1 and PMF-NOTT-2, respectively. Adsorption and desorption studies of N2 (77 K) and CO2 (273–303 K and 20 bar) were used to characterize the porosity of these materials. CO2 adsorption measurements indicate that these PMFs have similar porosity with Dubinin–Radushkevich micropore volumes of 0.142 and 0.144 cm3 g−1 and CO2 surface excess uptakes of 28.4 and 28.9 wt% at 20 bar, 273 K for PMF-NOTT-1 and PMF-NOTT-2, respectively. The isosteric heats of adsorption for CO2 at zero surface coverage were 31.9 kJ mol−1 (for PMF-NOTT-1) and 33.1 kJ mol−1 (for PMF-NOTT-2). However, N2 adsorption studies at 77 K indicated that PMF-NOTT-2 shows activated diffusion effects due to the presence of some narrow ultramicroporosity. The conjugated systems of these frameworks can be reversibly switched by varying proton concentration in solution and these materials thus demonstrate halochromic properties. PMF-NOTT-1, constructed from shorter building blocks than PMF-NOTT-2, exhibits higher catalytic activity and selectivity in Knoevenagel condensation reactions of malononitrile with benzaldehydes. The advantages of using PMFs as catalysts or adsorbents are their excellent thermal and chemical stabilities and they can be recovered and regenerated for re-use.

Graphical abstract: Porous macromolecular dihydropyridyl frameworks exhibiting catalytic and halochromic activity

Back to tab navigation

Supplementary files

Article information


Submitted
20 May 2014
Accepted
21 Aug 2014
First published
28 Oct 2014

J. Mater. Chem. A, 2014,2, 19889-19896
Article type
Paper
Author version available

Porous macromolecular dihydropyridyl frameworks exhibiting catalytic and halochromic activity

B. Xiao, T. L. Easun, A. Dhakshinamoorthy, I. Cebula, P. H. Beton, J. J. Titman, H. Garcia, K. M. Thomas and M. Schröder, J. Mater. Chem. A, 2014, 2, 19889
DOI: 10.1039/C4TA02521K

Social activity

Search articles by author

Spotlight

Advertisements