Crystal structure and luminescence spectra of Eu 2 ( p -MAB) 6 (PHEN) 2 complex

The title complex crystalizes in the space group P1 with a = 1.3349(7), b=1.9790(4), c= 1.2784 (7) nm, α = 97.67(1). β = 10636(1), γ=91.71(1)° ,Z = 2, Mr= 1475.19 and the final R = 0.051. Each asymmetric species in the crystal contains two crystallographically different Eu (p-CH3C6H4COO)3(C12H8N2) units. Two types of bmuclear molecules are formed by the combination of each of the units through inversion with corresponding units of (he closest asymmetric species. The former contains 4 bridged carboxylate groups bonded to the two central europium (III) ions, and the latter, only 2 bridged carboxylate anions Their Eu-Eu atomic distances are 0.4203 and 0.5298 nm respectively. In the 7F0→ 5D0, excitation spectrum of the complex, there are two sharp peaks al 580.07 and 580.73nm. This shows that the complex has two Eu(III) sites. Two different sets of 5D0→Fj (j= 1 - 4) luminescence spectra have been obtained at the selectively excited 5D0 levels of the complex, which indicates that Eu(III) ions in the complex have unequally chemical environments. This is in agreement with the results of the structure determination.