Metal-organic frameworks based on flexible bis(imidazole) and dicarboxylic ligands and their applications as selective sensors for magnesium nitrate

Uranyl ion coordination polymers with the dibenzobarrelene-based rac- and (R,R)-trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylate ligands

“…The carboxylate C⋯C separation for deadc 2− here is intermediate between those of the diaxial isomer of t -1,2-chdc 2− (3.86–3.88 Å) 9 c and its more commonly observed diequatorial form (2.96–3.12 Å) 9 a , b but closer to the former, indicating that it should favour polymer formation over that of closed oligomers. In the known transition metal ion complexes of deadc 2− , which are in fact both polymers, 6 the values for this separation (3.35–3.54 Å) fall within the range of the values given above. Another obvious difference between deadc 2− and t -1,2-chdc 2− is the much greater bulkiness of the dibenzobarrelene compared to the cyclohexane platform, and the presence of aromatic rings with the variety of interactions that they entail.…”

“…1–4 Less well established are the roles of its conjugate anions in coordination chemistry, though both deadcH − and deadc 2− have been shown to be useful counteranions for crystallization of organometallic cations 5 and structural studies of complexes formed with Co II and Cd II have shown deadc 2− to be suited to the formation of coordination polymers. 6 The acid deadcH 2 is chiral and while several methods are known for its resolution into enantiomers, 7 only in one instance has resolved deadc 2− been used as a ligand in an osmium complex, not structurally characterized, employed as a catalyst for asymmetric synthesis. 8…”