New Luminescent Lanthanide Tetrakis‐Complexes NEt4[LnL4] Based on Dimethyl‐N‐Benzoylamidophosphate

• Published in: Chemphyschem 2022-07, Vol.23 (14), p.e202200129-n/a
• Main Authors: Kariaka, Nataliia S., Trush, Victor A., Dyakonenko, Viktoriya V., Shishkina, Svitlana V., Smola, Sergii S., Rusakova, Nataliia V., Sliva, Tetiana Y., Gawryszewska, Paula, Carneiro Neto, Albano N., Malta, Oscar L., Amirkhanov, Vladimir M.
• Format: Article
• Language: English
• Subjects: Calixarenes; carbacylamidophosphate; coordination compounds; Gadolinium; Gravimetric analysis; lanthanide; Lanthanides; Luminescence; NMR; Nuclear magnetic resonance; thermal gravimetric analysis
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.202200129

New lanthanide dimethyl‐N‐benzoylamidophosphate (HL) based tetrakis‐complexes NEt4[LnL4] (Ln3+=La, Nd, Sm, Eu, Gd, Tb, Dy) are reported. The complexes are characterized by means of NMR, IR, absorption, and luminescent spectroscopy as well as by elemental, X‐Ray, and thermal gravimetric analyses. The phenyl groups of the four ligands of the complex anion are directed towards one side, while the methoxy groups are directed in the opposite side, which makes the complexes under consideration structurally similar to calixarenes. The effect of changing the alkali metal counterion to the organic cation NEt4+ on the structure and properties of the tetrakis‐complex [LnL4]‐ is analyzed. The complexes exhibit bright characteristic for respective lanthanides luminescence. Rather high intensity of the band of 5D0→7F4 transition, observed in the luminescence spectrum of NEt4[EuL4], is discussed based on theoretical calculations. A series of brightly luminescent lanthanide tetrakis‐complexes NEt4[LnL4] with dimethyl‐N‐benzoylamidophosphate is reported. The introduction of counter ion NEt4+ to the [LnL4]− complexes instead of Cs+ significantly influences the complexes’ physical properties. The complexes form at least two types of crystals. Europium and terbium compounds demonstrate luminescence with decay time 2.2 and 2.3 ms, respectively. Unusually high band intensity of 5D0→7F4 transition is observed in the luminescence spectrum of NEt4[EuL4] and discussed based on theoretical calculations.