Synthesis, molecular structure and fluorescence of an organic–inorganic hybrid complex [Eu(NO3)6][(Hphen)6·(NO3)2]·NO3 (phen=1,10-phenanthroline)

A new europium (III) complex, [Eu(NO3)6]{[(Hphen)6·2NO3]·NO3} (1) was prepared and structurally characterized in which Eu3+ is 12-coordinated to six bidentate nitrates. The coordination polyhedron around Eu3+ was described as a slightly distorted icosahedron. The six mono-protonated 1,10-phenanthrolines do not coordinate to the Eu3+ directively due to the formation of hydrogen bonds in form of O⋯H–N with two nitrates and also the formation of two face-to-face trigonal plates within which one free nitrate is sandwiched. 1 exhibits strong red and blue fluorescence when it was irradiated by UV light.