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.
A series of europium diketonate complexes with 1-phenyl-1,3-butanedione (PBD) and 1,10-phenanthroline derivatives were synthesized and explored spectroscopically. Photophysical characteristics of ...synthesized complexes have been investigated experimentally as well as theoretically. Photoluminescence emission spectra of complexes do not contain any peak of ligand revealing efficient transferal of energy from ligand to Eu
3+
ion. Presence of peak at 611 nm corresponding to
5
D
0
→
7
F
2
transition is responsible for red emanation of ternary europium complexes. Photophysical parameters viz
.,
Judd–Ofelt, quantum efficiency, radiative and non radiative decay rates were also estimated theoretically from LUMPAC software. Geometry optimization of complexes was done via Avogadro software. All synthesized trivalent complexes exhibit red emission which was further sustained by the position of chromaticity coordinates in CIE triangle. These red emanating materials could be utilized in designing electroluminescent display devices.
Graphical Abstract
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.
Ternary materials of europium complex with 2,2,6,6-tetramethyl-3,5-heptanedione (tmhd) ligand and aqua ligand as ancillary ligands have been prepared and characterized for various optoelectronic ...characteristics. Reactions of hydrated complex Eu(tmhd)
3
(H
2
O)
2
proceeded with triphenylphosphine oxide (TPPO) and pyridine-N-oxide (PNO) ancillary ligands were studied to develop novel complexes. The prepared complexes show good thermal stability. A comparative investigation of prepared materials Eu(tmhd)
3
(H
2
O)
2
, Eu(tmhd)
3
(TPPO)
2
and Eu(tmhd)
3
(PNO)
2
was conducted for their luminescent behaviors in order to obtain the role of ancillary ligand in the enhancement of illumination amount generated from europium (Eu
3+
) ion. Color coordinates of prepared ternary complexes such as Eu(tmhd)
3
(H
2
O)
2
with (
x
= 0.54,
y
= 0.32), Eu(tmhd)
3
(TPPO)
2
with (
x
= 0.56,
y
= 0.32) and Eu(tmhd)
3
(PNO)
2
with (
x
= 0.57,
y
= 0.33) indicated that these materials exhibited bright red emission in visible region spectrum. The complexes show a proficient energy transport pathway from the ligands to the innermost Eu
3+
by means of an ancillary ligand-sensitized luminescence process. Interaction between the metal and ligand results in a distinguished effect on quantum efficiency (
η
) as well as on Judd–Ofelt intensity factor (
Ω
2
) of the prepared materials.
Graphic abstract
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.
Single-phased cool white light emissive Gd3-xAl5O12:xDy3+ (x = 0.01–0.07) nanophosphors have been prepared via gel-combustion method. Diffraction data and Rietveld results have affirmed the ...development of a single cubic phase of all the prepared samples with space group Ia-3d (230). Furthermore, the crystallite size was calculated through Debye-Scherrer's formula and the Williamson-Hall method. In the EDX spectrum, the nonappearance of peaks analogous to the foreign elements affirms the pure synthesis of the considered phosphors. TEM observation reveals agglomerated porous crystalline material with non-uniform shapes and varying particle size in 20–80 nm range. Fourier Transform Infrared (FTIR) spectroscopy has been applied for the examination of chemical bonding with other vibrational characteristics. The luminescence study confirms the intense blue and yellow emission of synthesized phosphors at 482 nm and 576 nm respectively owing to 4F9/2→6HJ (J = 15/2, 13/2) transitions. Moreover, the detailed evaluation of the concentration quenching process established that dipole-quadruple interaction is answerable for the decrease in luminescence intensity after optimum dopant ion concentration. The chromatic analyses recommend that emission from the optimized nanophosphors lies in the region of cool white light. The outcomes of the present investigation propose that Gd3Al5O12:Dy3+ phosphors might be a potential candidate for white-LEDs applications.
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•Urea based gel-combustion method has been utilized for the synthesis of Gd3-xAl5O12:xDy3+ (x = 0.01 to 0.07) nanophosphors.•XRD data based Rietveld refinement technique confirms the formation of cubic crystal phase.•The crystallite size and lattice microstrain were calculated by Debye-Scherrer's and Williamson-Hall method.•Dipole-quadrupole interactions are accountable for the phenomenon of concentration quenching.•Combination of blue and yellow bands in the emission spectra is responsible for the white emission of the considered nanomaterials.
