Similarities of Coordination Polymer and Dimeric Complex of Europium(III) with Joint and Separate Terpyridine and Benzoate

A dimeric complex of trivalent europium [Eu₂Cl₄(bc)₂(ptpy)₂] (1), containing the separate ligands 4'‐phenyl‐2,2':6',2''‐terpyridine (ptpy) and benzoate (bc^–) and a one‐dimensional double strand coordination polymer of the composition ¹_∞[EuCl₂(cptpy)] (2) with 4‐[2,2':6',2''‐terpyridin]‐4'‐yl‐benzoate (cptpy^–) were obtained. The products exhibit structural similarities despite the character of joint and separate functionality of the ligands. The dimer 1 shows photoluminescence with high quantum yield [61(2)%]. Eu³⁺ emission lifetime is 1.493(1) ms at room temperature and rises to 1.649(1) ms upon cooling to 77 K.