Mononuclear luminous β‐diketonate Ln(III) complexes with heteroaromatic auxiliary ligands: synthesis and luminescence characteristics

• Published in: Luminescence (Chichester, England) Vol. 37; no. 11; pp. 1921 - 1931
• Main Authors: Hooda, Anjli, Dalal, Anuj, Nehra, Kapeesha, Kumar, Pawan, Singh, Devender, Kumar, Sumit, Malik, Rajender Singh, Kumar, Ramesh, Kumar, Parvin
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01-11-2022
• Subjects: auxiliary ligands; Differential thermogravimetric analysis; Diketones; Electrochemistry; Emission analysis; Emissions; Infrared analysis; Irradiation; Ligands; Light emitting diodes; luminescence; Metal ions; Metals; Nitrogen atoms; paramagnetic NMR; Samarium; Terbium; ternary lanthanide complexes; Thermal stability; Thermogravimetry; Ultraviolet radiation
• ISSN: 1522-7235; 1522-7243
• DOI: 10.1002/bio.4376

A series of lanthanide (samarium and terbium) β‐diketonates with heteroaromatic auxiliary ligands was synthesized. The prepared complexes were characterized through electrochemical, thermal, and spectroscopic analyses. Infrared analysis revealed the binding of the respective metal ion to oxygen and nitrogen atoms of diketone and ancillary ligands. Thermogravimetry/differential thermogravimetry profiles provided thermal information and specified the high thermal stability of the prepared complexes. The complexes exhibited the sharp and structured Ln‐based emission in the visible region upon irradiation in the ultraviolet range. Photophysical analysis demonstrated the green and orange‐red emission due to the respective characteristic transitions of Tb3+ and Sm3+ ions. Photophysical properties affirmed the luminous behaviour of the synthesized complexes. These luminous lanthanide complexes could be used as emitting materials in the design of organic light‐emitting diodes.
Octa‐coordinated Ln(III) {Sm, Tb} complexes with 2,2‐dimethyl‐6,6,7,7,8,8,8‐heptafluoro‐3,5‐octanedione (Hfodo) and 1,10‐phenanthroline (Phen) derivatives were synthesized. The bathochromic shift of absorption maxima is observed after complexation in respective series. Synthesized complexes show the sharp and structured Ln‐based emissions in visible region upon irradiation in UV range. The luminous nature of prepared complexes specifies the effective intramolecular energy transfer to Ln3+ ion via sensitization mechanism.