Synthesis, structure, and photoluminescent properties of a mixed carboxylate pentafluorobenzoate–phenylacetate complex of terbium

A complex of mixed carboxylate pentafluorobenzoate (pfb) and phenylacetate (PhAc), viz. [Tb₂(phen)₂(pfb)₂(PhAc)₄] (phen is 1,10-phenanthroline), where each rare earth element (REE) ion is simultaneously coordinated to pentafluorobenzoic and phenylacetic acid anions, was for the first time synthesized and structurally characterized. To evaluate the influence of the second type of anion on the structure and photoluminescent properties, compounds with phenylacetic acid anions [Tb₂(phen)₂(PhAc)₆] and pentafluorobenzoic acid anions [Tb₂(EtOH)₂(phen)₂(pfb)₆] were obtained. A change in the composition of the compounds from the phenylacetic acid anion to pentafluorobenzoate led to a change in the geometry of the metal scaffold and the REE polyhedron, a rearrangement of the system of non-covalent interactions according to the Hirshfeld surface analysis, and enhanced luminescence.