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.