Uranyl ion coordination polymers with the dibenzobarrelene-based rac- and (R,R)-trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylate ligands
Résumé
Trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (deadcH$_2$), in its racemic or R,R
enantiomeric forms, has been used to synthesize eight uranyl ion complexes under solvo-hydrothermal
conditions. [UO$_2$(deadc)]-1.5CH$_3$CN (1) and [H$_2$NMe$_2$]$_2$[(UO$_2$)$_2$(deadc)$_3$]-2H$_2$O (2) crystallize as monoperiodic coordination polymers in which dead$^{2–}$forms both 4- and 7-membered chelate rings. Although synthesized in the same conditions as 2, the enantiomerically pure complex [H$_2$NMe$_2$]$_4$[(UO$_2$)$_2$(O)(R,R-deadc)$_2$]$_2$ (3) is a discrete tetranuclear complex containing two -3-oxo anions. Association with the zwitterion Ni(tpyc)$_2$, where tpyc$^–$ is 2,2":6ʹ,2--terpyridine-4ʹ-carboxylate, gives [(UO$_2$)$_2$(deadc)(deadcH)(NO$_3$)Ni(tpyc)$_2$]-CH$_3$CN-2$_2$O (4), a rakeshaped monoperiodic assembly. [UO$_2$(deadc)(DMA)] (5), [UO$_2$(deadc)] (6) and [PPh$_4$]$_2$[(UO$_2$)$_2$(R,R-deadc)$_3$] (7)
crystallize as diperiodic networks with the fes, sql and hcb topologies, respectively, the thick layers formed
being coated on both sides by protruding, hydrophobic dibenzobarrelene groups. Finally,
[(UO$_2$)$_2$Ag$_2$(deadc)$_3$(CH$_3$CN)$_2$]-0.5H$_2$O (8) contains monoperiodic uranyl–deadc$^{2–}$
subunits which are assembled into a triperiodic framework by bridging silver(I) cations, the latter interacting with both carboxylate groups and aromatic rings. Except for 6, all these complexes are emissive with photoluminescence quantum yields of 2–26%, and most spectra display the usual vibronic fine structure of uranyl emission.