Chain-like uranyl-coordination polymer as a bright green light emitter for sensing and sunlight driven photocatalysis

摘要

A new uranyl-coordination polymer (UCP) has been solvothermally synthesized employing succinic acid and 1,10-phenanthroline (phen) as ligands. The obtained compound with the formula [(UO2)(2)(phen)(succ)(0.5)(OH)(O)(4)(mu(3)-O)(H2O)]center dot H2O (UNSL-1) is classified as 1D chains showing I(0)O(1)connectivity. Also, the asymmetric unit is composed of two hepta-coordinated uranyl centers: U1 is surrounded by five oxygen atoms from succinate, while U2 is surrounded by two nitrogen atoms from phen and three oxygen atoms from succinate ([U1O(7)] and [U2N(2)O(5)]). The secondary-building unit (SBU) is composed of a sharing edge tetrameric cluster linked with a succinate ligand in the [-1 0 1] direction. Besides, the chains are reinforced by pi-pi stacking interactions between the aromatic rings of the phen molecules to conform a 2D supramolecular arrangement. Moreover, photoluminescence experiments show strong green emission consistent with uranyl crystalline materials. Photophysical characterization was completedvialow-temperature measurements (77 K) and recording the decay emission for calculating the lifetime (tau(obs)) value. Regarding its multifunctional properties, a cation-sensing performance was achieved showing selective quenching toward iron ions in aqueous media. Finally,UNSL-1was tested as an efficient water photocatalyst for dye degradation under simulated sunlight irradiation, exhibiting promising results for organic-pollutant water remediation.