Photoluminescence Tuning and Water Detection of Yttrium Diazinedicarboxylate Materials through Lanthanide Doping

A series of yttrium(III)-based compounds with three diazinedicarboxylate ligands, namely, {[Y-2(-pmdc)(2)(-ox)(H2O)(6)]4H(2)O}(n) (1, pmdc = pyrimidine-4,6-dicarboxylato, ox = oxalato), {[Y-2(-pmdc)(3)(H2O)(6)]2DMF8H(2)O}(n) (2, DMF = N,N-dimethylformamide), {[Y-2((3)-pmdc)(2)(-ox)(H2O)(4)]xH(2)O}(n) (3, x approximate to 4.66), {[Y((4)-pmdc)(NO3)(H2O)]H2O}(n) (4), [Y-2(-pddc)(3)(H2O)(6)]7H(2)O (5, pddc = pyridazine-3,6-dicarboxylato) and {[Y-6((4)-pzdc)(6)(NO3)(H2O)(16)](NO3)(5)2H(2)O}(n) (6, pzdc = pyrazine-2,5-dicarboxylato), have been prepared by different synthetic approaches. The crystal structures range from 0D to 3D architectures, and all of the compound show solvent-occupied volumes. The thermal behaviour of these compounds has been analysed, and the open structure of 3 shows a reversible uptake/release of water. Moreover, the yttrium matrix of 3 has been doped with Eu3+ and Tb3+ ions to investigate the photoluminescence response of the hybrid materials. In addition to a tuneable emission colour through the concentration of luminescent ions and the excitation wavelength, these hybrid materials could serve as potential photofluorescent sensors for water detection through the reversible dehydration/rehydration process.