New lanthanide complexes with CAPh type ligand dimethyl-N-benzoylamidophosphate and an additional ligand triphenylphosphine oxide. Synthesis, crystal structure, luminescent and thermal properties

Abstract The novel coordination compounds of general formula [LnL3TPPO] (Ln3+ = Nd3+, Eu3+, Gd3+, Tb3+, Tm3+, Lu3+, HL = dimethyl-N-benzoylamidophosphate, TPPO = triphenylphosphine oxide) and the complex [Tm5L6(μ-L)4(μ3-OH)4(μ4-OH)] were obtained and characterized by elemental, X-ray and TG analyses, IR and luminescent spectroscopy. By means of X-ray diffraction method it was found, that CAPh-ligands are coordinated to lanthanide(III) ions in bidentate chelate manner through oxygen atoms of the carbonyl and phosphoryl groups. In [LnL3TPPO] compounds oxygen atom of TPPO ligand complete coordination number of lanthanide ion to seven, while in [Tm5L6(μ-L)4(μ3-OH)4(μ4-OH)] the Tm3+ ion is eight coordinated. In crystal packing of the obtained complexes there are numerous short contacts between neighboring molecules. The coordination compounds were found to be resistant to temperature of 200 °C. Upon excitation by UV light the complexes [EuL3TPPO], [TbL3TPPO] and [TmL3TPPO] show lanthanide centered, respectively red, green and blue emission. The Eu3+ and Tb3+ complexes emission is characterized by decay time 1.30 and 1.56 ms respectively. Intrinsic quantum yield for [EuL3TPPO] equals 80%.