Synthesis, structural characterization, and luminescence properties of heteroleptic bismuth-organic compounds

Four heteroleptic bismuth-organic phases bearing 2,2′;6′,2′′-terpyridine (terpy) and 2-thenoyltrifluoroacetone (TTA) of the general formula [BiX y (TTA) 3− y (terpy)], where X = NO 3 ( 2 ), Cl ( 3 ), Br ( 4 ), Br 2 ( 5 ), were synthesized at room temperature. A minor phase, [Bi 2 (terpy) 2 (MeO) 2 (NO 3 ) 4 ] ( 1 ), formed in the same reaction as 2 , and was manually separated to afford a phase pure sample of 2 . The structures were determined through single crystal X-ray diffraction, and further characterized via powder X-ray diffraction, Raman spectroscopy, and thermogravimetric analysis. The structures of 2-5 are built from discrete monomeric units, whereas 1 contains dimeric complexes. Significant π-π stacking and halide-π interactions are observed in the solid-state structures. Europium-doped phases of 2-5 were synthesized through addition of an aliquot of a europium nitrate or europium chloride solution to the initial reaction solution. For comparison, [EuNO 3 (TTA) 2 (terpy)]·0.3MeOH ( 6 ), which is isostructural to 2 , was synthesized. Photophysical measurements were carried out for each of the lanthanide containing phases, and quantum yield and lifetime values were determined for the visible-light emitters. The synthesis, structural chemistry, and spectroscopic properties of the phases are presented. The synthesis and photoluminescent properties of four bismuth-organic compounds, their lanthanide doped analogs, and an isostructural europium complex are reported.