This article presents four ternary terbium complexes based on fluorinated 2-thenoyltrifluoroacetone (TTFA) and N donor bidentate neutral ligands. The prepared complexes were examined by elemental ...study, electrochemical analysis, spectroscopically and thermo-gravimetrically. Spectral analysis shows the bonding of Tb
3+
ion with oxygen and nitrogen atom of diketone and neutral ligand respectively. Upon excitation in UV region, synthesized terbium complexes show luminescence in green region of electromagnetic spectrum. Photoluminescence emission spectra of complexes do not show any ligand based peak suggesting the effective transferal of energy from ligand to metal ion. Green emanation by terbium complexes is owing to intense peak ~547 nm (
5
D
4
→
7
F
5
). The outcome of emission data and CIE coordinates correlate with each other and affirms the utility of green luminous complexes as potential emissive material for optoelectronic gadgets applied in lighting system.
Graphical abstract
1,10-Phenanthroline-based luminescent materials play an important role as an excellent class of optoelectronic materials due to their remarkable and novel attributes for optoelectronic applications. ...There is an enormous demand of luminescent materials in many fields. The foremost objective of this paper is to synthesize fluorescent derivatives of 1,10-phenanthroline. The electronic effect of the substituents on the heteroaromatic ligand has been reviewed in solid state. These ligands were characterized by electrochemical study and spectroscopically. The value of energy band gap is estimated to be 3.0–4.5 eV for synthesized compounds. Photophysical features were analyzed through photoluminescence spectrometer, which indicates a strong impact of the substituents on the photoluminescent properties of the phenanthroline ligand. Upon excitation in ultraviolet region, intense broad band appeared in emission spectra of synthesized compounds lie in visible region which is further supported by CIE color coordinates. The detailed explanation about the geometry and frontier molecular orbitals calculation was carried out with the help of Avogadro and ORCA software.
The octa-coordinated complexes of Sm(III) with
β
-diketone and nitrogen-heterocyclic bidentate auxiliary moiety were prepared and characterized spectroscopically. Spectral outcomes of complexes have ...suggested the isostructural behavior of ternary complexes. Optical bandgap (
E
g
) values of complexes were evaluated from Tauc’s plot. The photoluminescence emission spectra of ternary complexes show Sm
3+
-based peaks at 566, 601, 648, and 707 nm attributed to
4
G
5/2
→
6
H
J
(
J
= 5/2–11/2) transitions. Most intense peak at 648 nm is responsible for orange-red emanation of samarium complexes. Colorimetric analysis of complexes supports the results of emission spectra. The fascinating optical properties of ternary metal complexes in the orange-red visible spectral region might be valuable in designing optoelectronic devices and displays.
Trivalent europium complexes exhibit good luminescent characteristics. A series of octacoordinated ternary europium complexes with fluorinated diketone and heteroaromatic auxiliary unit were ...synthesized. The synthesized europium complexes were characterized by elemental, thermal, electrochemical and spectroscopic analyses. Band gap values lie in range of semiconductors which confirm the conducting behavior of prepared complexes. Photoluminescence spectra were recorded in solid state and DMSO solvent. Emission spectral profiles have displayed most intense peak at ~ 612 nm corresponding to hypersensitive
5
D
0
→
7
F
2
transition. Colorimetric parameters suggest red luminous nature of europium complexes. The luminescent heteroleptic europium complexes might be utilized as emissive materials for fabricating display.
Graphical Abstract
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•The samarium based red optoelectronic complexes are synthesized with heteroaromatic ligands and are characterized spectroscopically.•Photoluminescence emission spectra exhibit ...intense sharp peak at 647 nm ascribed to 4G5/2→6H9/2transition, which is responsible for red luminescence by ternary complexes.•Optical band gap values lie in semiconductor range and are responsible for the utilization of these complexes in luminescent display devices.
Four new heteroleptic samarium complexes showing reddish orange luminescence of type Sm(TFNB)3L {TFNB = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione; L = 1,10-phenanthroline (Phen); 3,8-dibromo-1,10-phenanthroline (PBr); 3-bromo-8-(3,4-(ethylenedioxy)thien-2-yl)-1,10-phenanthroline (MP) and 3,8-bis(3,4-(ethylenedioxy)thien-2-yl)-1,10-phenanthroline (DP)} were prepared and investigated. Herein, we sought to enhance the luminescence properties of samarium complexes by using different phenanthroline derivatives. The complexes were characterized by elemental analysis, thermogravimetric and spectroscopic techniques. The hypersensitive peak at 647 nm in emission spectra is responsible for the emission in visible region. The color coordinates of all the Sm(III) complexes depict reddish orange emission. Thermogravimetric data claim the thermal stability of complexes upto a range of temperature. The synthesized complexes having ∼3 eV optical band gap and narrow orange red emission might be useful in display applications.
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•Ternary terbium complexes with 1-phenyl-1,3-butanedione and heteroaromatic bidentate neutral ligands were synthesized and spectroscopically investigated.•Most intense at 548 nm ...credited to 5D4→7F5 is responsible for the characteristic green emission of synthesized terbium complexes.•The band gap values have illustrated the conducting behavior of complexes as situated in the range of semiconductor materials.•Due to high color purity and better thermal stability, these complexes might be utilized as green emissive component in displays.
Green luminescent complexes of terbium based on derivatives of 1,10-phenanthroline auxiliary ligand and 1-phenyl-1,3-butanedione (PBD) with general formula Tb(PBD)3L were synthesized. The complexes were characterized by spectroscopic and thermal methods. Photoluminescence spectra demonstrated that on excitation under UV radiations, four emission peaks were displayed in the emission spectra. These characteristic peaks appeared due to transition from the energized (5D4) to the ground state (7FJ) positioned at 491, 547, 584, 622 nm, where J = 6–3 respectively. The hypersensitive peak located at 547 nm is responsible for the characteristic green emission of terbium ion. Absorption and electrochemical analytical results point out the application of synthesized complexes in lighting and displays. Optical and electronic band gap in 3–4 eV range were also found comparable to each other and revealed the use of ternary terbium complexes as semiconductor material.
A series based on octa coordinated tris(2-benzoylacetophenonate)europium complexes were synthesized with bidentate heteroaromatic auxiliary ligands. 2,2′-Bipyridine (Bpy) and its derivatives ...synthesized in the laboratory were used as auxiliary ligands. The structural analysis of synthesized materials was done by various spectroscopic techniques. Their photoluminescent characteristics specified the effective sensitization of trivalent europium ion via antenna effect. As an outcome of this sensitization, these complexes demonstrate good luminescence intensity, high quantum efficiency and long luminescence lifetime. The CIE chromaticity coordinates (x, y and u’, v’) were designed to indicate bright red emission. Luminescence decay time data were calculated by investigating the λem well-suited with the transition of the type 5D0→7F2. The molecular parameters of the geometrically optimized complexes were derived from the semi-empirical Sparkle/RM1 method. Theoretical Judd-Ofelt and photophysical parameters were estimated by LUMPAC software ascribed with experimental data, indicating the efficacy of this method. Furthermore, these luminous ternary europium complexes can be utilized as red light emitting material in designing flat panel displays and various optoelectronic devices.
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•Structural and photophysical investigation of luminescent red color emissive ternary europium complexes have been carried out experimentally and theoretically.•The main objective of analysis is to study the impact of substituted neutral ligands on optoelectronic properties of complexes.•Photoluminescence emission spectra of all synthesized complexes show most intense peak at 612 nm corresponding to electric dipole transition (5D0.→7F2).•Significant FMO's along with their energy have been estimated via Avogadro and ORCA software.•The bright red emission of Eu(III) complexes makes them suitable for utilization in optoelectronic devices.
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•Luminescent green terbium diketonate complexes with N donor auxiliary ligands have been synthesized.•Optical and photophysical characteristics of ternary terbium complexes were ...explored in detail.•Infrared spectral analysis suggests the binding of Tb3+ ion with oxygen and nitrogen atoms of TFNB and substituted 1,10-phenanthroline derivatives respectively.•CIE color coordinates and color purity also claims for green emission and high luminous nature of Tb3+ complexes.
A series of luminescent ternary terbium complexes based on fluorinated ligand 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (TFNB) and other auxiliary ligands were synthesized and explored. Optical and photophysical characteristics of complexes were examined spectroscopically. Thermal and electrochemical behavior of complexes is also reported. In emission spectra of complexes, four characteristic peaks of Tb3+ ion at 492 nm, 548 nm, 586 nm and 615 nm accredited to 5D4 → 7FJ (J = 6–3) transitions appeared upon excitation in UV region. Most intense peak at 548 nm is accountable for bright green emission of ternary complexes. Color purity and CIE parameters also suggest the green luminous behavior of complexes. Our investigation has revealed that the synthesized complexes could be used in preparing lighting system, OLEDs and display devices owing to their luminescent characteristics.
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The eight coordinated complexes of samarium were synthesized with dibenzoylmethane (DBM) and bidentate auxiliary ligand. Ternary complexes of samarium of the type Sm(DBM)3L ...(L = 1,10-Phenanthroline or its derivatives) were prepared by one step method. These complexes were characterized by spectroscopic techniques and thermo-gravimetric analysis. The proton-NMR data of all the complexes are reliable with the coordination of three DBM units and one neutral unit. Luminescence spectra of the complexes taken in powdered form, illustrate the bright red luminescence at 648 nm upon UV excitation that is accredited to the 4G5/2→6H9/2 transition of Sm3+ ion. The domination of hypersensitive transition corresponding to 648 nm reflects the asymmetric environment around samarium ion and their intensity undergoes significant change on variation in the binding environment about metal ion. The intense luminescence and color coordinates demonstrate that the complexes might be used as promising candidate in displays and light emitting devices.
