Crystal structure and luminescence of a new europium coordination polymer {[Eu(α-FURA)3·2H2O]·NO3(4,4′-Hbpy)}∞

Abstract

The structure of a europium complex {[Eu(α-FURA)3·2H2O]·NO3(4,4′-Hbpy)}∞ (α-FURA: α-furoate, 4,4′-Hbpy: protonated 4,4′-bipyridine) was determined by single crystal X-ray diffraction. Each europium is coordinated with two oxygen atoms of chelated carboxyl group, four oxygen atoms of bridging carboxyl groups and two oxygen atoms from two water molecules forming a coordination polymer with coordination number of eight. 4,4′-bipyridine is protonated and one of the bonded water molecules forms hydrogen bond with NO3− in the crystal. The luminescence behavior of the Eu3+ ion in {[Eu(α-FURA)3·2H2O]·NO3(4,4′-Hbpy)}∞ was observed at 77K. Its luminescence lifetime and the emission spectra of 5D1→7FJ (J=1–3) and 5D0→7FJ (J=0–4) transitions were measured. The complex displays intense luminescence and the Eu3+ ions in the polymer occur in the same chemical environment. And its crystal structure also shows that only one site for Eu3+ ion is in the europium coordination polymer.