Synthesis and Characterization of Coordination Compound [Eu(µ(2)-OC(2)H(5))(btfa)(NO(3))(phen)](2)phen with High Luminescence Efficiency

A high-luminescent, blue-light excitable europium(III) coordination complex, [Eu(µ(2)-OC(2)H(5))(btfa)(NO(3))(phen)](2)phen (1) {btfa = benzoyl trifluoroacetone, phen = 1,10-phenantroline}, has been synthesized and investigated. The complex was characterized by infrared (IR) and photoluminescence (PL) spectroscopy. The PL emission spectra of powder samples registered in a range of 10.7–300 K exhibit characteristic metal-centered luminescence bands, assigned to internal radiative transitions of the Eu(3+) ion, (5)D(1)→(7)F(j) and (5)D(0)→(7)F(j) (j = 0–4). The high-resolution spectrum of the transition (5)D(0)→(7)F(0) shows that it consists of two narrow components, separated by 0.96 meV, which indicates the presence in the matrix of two different sites of the Eu(3+) ion. The splitting pattern of (5)D(0)→(7)F(j) (j = 0–4) transitions indicates that europium ions are located in a low-symmetry environment. The absolute quantum yield and the sensitization efficiency were determined to be 49.2% and 89.3%, respectively. The complex can be excited with low-cost lasers at around 405 nm and is attractive for potential applications in optoelectronics and biochemistry.