Crystal structure and luminescence of a new europium coordination polymer {[Eu(alpha-FURA)(3)center dot 2H(2)O]center dot NO3(4,4 '-Hbpy)}(infinity)

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 europi um is coordinated with two oxygen atoms of chelated carboxyl group, four ox ygen 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 observ ed 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 measure d. The complex displays intense luminescence and the EU3+ ions in the polym er occur in the same chemical environment. And its crystal structure also s hows that only one site for Eu3+ ion is in the europium coordination polyme r. (C) 2001 Elsevier Science B.V. All rights reserved.