Investigation of binding tendency of Eu(III) and La(III)-Schiff base complexes to selected oxy-anions and amino acids

Deciphering intersystem crossing and energy transfer mechanisms in a nonacoordinated ternary europium(iii) complex: a combined spectroscopic and theoretical study

A monochromatic red emitting nonacoordinate organoeuropium complex with the formula [Eu(hfaa)3(Ph-TerPyr)] (Eu-1) incorporating hexafluoroacetylacetone (hfaa) primary ligands and a tridentate 4'-phenyl-2,2':6',2''-terpyridine (Ph-TerPyr) ancillary ligand has been synthesized. The complex was characterized by analytical and spectroscopic methods, and its structure was established by single crystal X-ray diffraction (SC-XRD) analysis at low temperature, which explicitly confirms that the coordination sphere is composed of a EuO6N3 core. Under the UV excitation, Eu-1 displayed typical red emission in solution with a long-excited state lifetime (τ obs = 1048.06 ± 9.39 μs) with a good photoluminescence quantum yield (Q L Eu = 41.14%). We have utilized pump-probe ultrafast transient absorption spectroscopy in tandem with the time-dependent density functional theory (TD-DFT) and the Lanthanide Luminescence Software Package (LUMPAC) to explore the intricate photophysical event that occurs in the vicinity of the ligands of Eu-1 sensitized photoluminescence (PL).

Single component white-OLEDs derived from tris(β-diketonato) europium(III) complexes bearing the large bite angle N^N 2-(4-thiazolyl)benzimidazole ligand

Two new organo-europium complexes (OEuCs) [Eu(tfac)3(TB-Im)] (Eu1) [Eu(hfac)3(TB-Im)] (Eu2) incorporating fluorinated (hexafluoroacetylacetone; Hhfaa) or hemi-fluorinated (trifluoroacetylacetone; Htfac) β-diketones together with the large bite angle N^N ligand (2-(4-Thiazolyl)benzimidazole; TB-Im) have been...

Heterometal Grafted Metalla-ynes and Poly(metalla-ynes): A Review on Structure-Property Relationships and Applications

Metalla-ynes and poly(metalla-ynes) have emerged as unique molecular scaffolds with fascinating structural features and intriguing photo-luminescence (PL) properties. Their rigid-rod conducting backbone with tunable photo-physical properties has generated immense research interests for the design and development of application-oriented functional materials. Introducing a second d- or f-block metal fragment in the main-chain or side-chain of a metalla-yne and poly(metalla-yne) was found to further modulate the underlying features/properties. This review focuses on the photo-physical properties and opto-electronic (O-E) applications of heterometal grafted metalla-ynes and poly(metalla-ynes).

Utilization of a Pt(ii) di-yne chromophore incorporating a 2,2'-bipyridine-5,5'-diyl spacer as a chelate to synthesize a green and red emitting d-f-d heterotrinuclear complex

A new heterotrinuclear (d-f-d) complex [Eu(btfa)₃1c] (btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione and 1c = [(Ph)(Et₃P)₂Pt-C[triple bond, length as m-dash]C-R-C[triple bond, length as m-dash]C-Pt(Et₃P)₂(Ph)] (R = 2,2'-bipyridine-5,5'-diyl) has been synthesized by utilizing the N,N-donor sites of the organometallic chromophore. The complex was characterized by analytical and spectroscopic methods. Photophysical properties of the complex were analysed in detail using both steady-state and time-resolved emission and excitation spectroscopy. The optical absorption spectrum of the complex is dominated by the spin allowed π-π* transitions of the btfa and 1c units in the UV-visible region (200-418 nm) and thus is excitable over a wide range of wavelengths across the UV into the visible region of the electromagnetic spectrum. The complex displays typical red Eu(iii) emission when excited at 345 nm. However, it also shows green emission when excited at 464 nm and, thus could be an interesting candidate for full colour display applications. The change in the colour could be a result of the high value of the energy back-transfer rate (6.73 × 10⁵ s^-1) from the triplet state of the organometallic chromophore to the ⁵D₁ state of Eu(iii). Judd-Ofelt (J-O) intensity parameters (Ω₂ and Ω₄), radiative (A_R), non-radiative (A_R) decay rates and intrinsic quantum yield (Q) have been calculated.