Coordination polymers based on 3,5-di-tert-butylbenzoate {Cd2Eu} moieties

Abstract Heterometallic complex [Cd2Eu(bzo)6(NO3)(MeCN)2(THF)2].2EtOH was synthesized by the reaction of Cd(NO3)2·4H2O and Eu(NO3)3·6H2O with potassium 3,5-di-tert-butylbenzoate (Hbzo). N-Donors (L) could replace solvents in the Cd coordination environment without modifying the stable metal core {Cd2Eu(bzo)6(X)} (X = NO3 or bzo). The presence of pyrazine (pz) in the reaction mixture could result in the formation of either molecular [Cd2Eu(bzo)6(NO3)(pz)2(EtOH)2] or 1D-polymeric [Cd2Eu(bzo)6(NO3)(pz)(H2O)2]n complex, depending on the Cd : L molar ratio (1 : 15 and 1 : 8, respectively). Addition of bridging N-donors 4,4′-bipyridine (4,4′-bipy) and 1,2-bis(2-pyridyl)ethylene (bpe) (Cd : L = 1 : 2) gave the [Cd2Eu(bzo)7(4,4′-bipy)(H2O)2]n and [Cd2Eu(bzo)7(bpe)(H2O)2]n polymers, respectively. 4-Methyl-2-aminopyridine (ampy) gave only molecular compound [Cd2Eu(bzo)7(ampy)2(EtOH)(H2O)] (Cd : L = 1 : 3). The structures of all the resulting compounds were studied by single crystal X-ray diffraction analysis. Photoluminescent properties were studied for solid samples of the synthesized compounds. The effect of the N-donor ligand geometry and the Eu…Eu distance on the lifetime of the Eu3+ atom’s 5D0 excited state is discussed.