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Lightweight Ionic Networks Composed of Li + or Mg 2+ Centres Linked Together by Dicarboxylate Ligands
Author(s) -
White Keith F.,
Abrahams Brendan F.,
Hudson Timothy A.,
Robson Richard
Publication year - 2016
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.201600274
Subject(s) - chemistry , crystallography , molecule , carboxylate , pyridine , solvent , crystal structure , ionic bonding , hydrogen bond , stereochemistry , metal , ion , inorganic chemistry , medicinal chemistry , organic chemistry
Abstract The combination of lightweight metal cations with a range of dicarboxylate ligands has led to the generation of ionic network materials that possess channels occupied by solvent molecules. The compounds [Li 2 (2,2‐bpdc)(DMF) 2 ] and [Mg(2,2‐bpdc)(DMF) 2 ] (2,2‐bpdc=2,2‐dipyridyl‐4,4‐dicarboxylate) adopt a similar structure in which parallel metal–carboxylate chains are linked to four equivalent chains to generate a 3 D network in which DMF molecules occupy channels. [Li 4 (3,5‐pdc) 2 (DMF)]⋅solvate (3,5‐pdc=3,5‐pyridine dicarboxylate) adopts a similar structure but the chains are more complex. As with the other structures, coordinated DMF molecules occupy network channels. [Li 4 (3,5‐pdc) 2 (DMF)]⋅solvate is able to adsorb carbon dioxide at elevated pressures with the adsorption following a type V isotherm; hysteresis is apparent upon desorption. The final compound, Li[Mg 3 OH(2,2‐bqdc) 3 (DMF/H 2 O) 3 ]⋅solvate (2,2‐bqdc=2,2‐biquinoline‐4,4‐dicarboxylate) has a distinctly different structure in which a trio of magnesium centres bound to a central μ 3 ‐hydroxide ion serves as a 6‐connecting, trigonal prismatic node within a 3 D network that has the point symbol, 4 9 6 6 . Solvent‐filled intraframework spaces represent over 50 % of the crystal volume and are occupied by highly disordered solvent and Li + ions. Immersion of Li[Mg 3 OH(2,2‐bqdc) 3 (DMF/H 2 O) 3 ]⋅solvate in a solution of Fe(2,2‐bipyridine) 3 2+ results in the incorporation of the Fe II complex into the large channels of the anionic network.