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

The structure of a europium complex {[Eu(alpha -FURA)(3). 2H(2)O]. NO3(4,4'-Hbpy)}(infinity) (alpha -FURA: alpha -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 NO; in the crystal. The luminescence behavior of the Eu3+ ion in {[Eu(alpha -URA)(3). 2H(2)O]. NO3(4.4'-Hbpy)}(infinity) was observed at 77 K. Its luminescence lifetime and the emission spectra of D-5(1) --> F-7(J) (J = 1-3) and D-5(0) --> F-7(J) (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. (C) 2001 Elsevier Science B.V. All rights reserved.