Synthesis and properties of Mg2+ and Sr2+ coordination compounds based on in situ synthetized pyromellitdihydrazidate ligand

Abstract

Two new pyromellitdihydrazidate-coordinated complexes [Mg(pmdh)(H2O)4] 1 and [Sr2(pmdh)(ox)(H2O)2]⋅2H2O 2 (pmdh = pyromellitdihydrazidate, ox = oxalate) were obtained by the hydrothermal ligand in situ reaction of pyromellitic acid with N2H4⋅H2O. In compound 1, the pmdh ligands exhibit a μ2-bridging mode, which link Mg(II) centers into a 1-D chained structure with ancillary H2O molecules. Interestingly, in compound 2, the ox ligands exhibit a special μ6-bridging mode, which first link Sr(II) centers into a 2-D layered structure. Further, pmdh I and pmdh II with different μ4-bridging mode act as the second linkers, extending the metal-ox layers into a 3-D network. The solid-state photoluminescence analysis indicates that both the title compounds are fluorescent materials with maximum emissions at 509 nm for 1, 470 nm for 2, respectively.