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Fossil fuel has empowered a remarkable era of prosperity and development of the welfare of human society. However, the resulting large anthropogenic CO2 emissions had an adverse ...impact on global temperature. Furthermore, the scarcity of limited fossil fuel resources will eventually force them to look for alternative carbon sources to sustain a sustainable economy. Chemical fixation of CO2 into fuels and valuable chemicals via renewable energy sources has been attracting human society for not only alleviating CO2 emissions but also reducing reliance on non-renewable energy sources and minimizing the impact on the environment from displaced fossil fuel fractions. Cyclic carbonate is a valuable CO2 product that can be used as aprotic solvent, the electrolytic solvent in lithium batteries, degreasing solvents, and intermediates for the synthesis of polycarbonates, drugs, and cosmetics. It can be synthesized via cycloaddition of CO2 with epoxide under the catalytic condition due to the low reactivity of CO2 (thermodynamic as well as kinetic inert). An ideal catalyst for this conversion is composed of a Lewis acid to activate the epoxide ring and a Lewis base to open the epoxide ring. Efforts have been done to synthesize various catalytic systems for cyclic carbonate formation. The review is focused on metal-catalyzed cyclic carbonate formation. It begins with carbon capturing, storage, and utilization (CCSU) along with the importance of cyclic carbonate. The mechanism for cyclic carbonate formation was classified into two categories including binary and bifunctional systems based on the presence of nucleophilic moiety either as a separate entity or attached to a catalyst. Various metal catalysts such as metal salen, metal porphyrin, metal salts, metal–organic framework, and zeolitic imidazolate framework are discussed with recent progress in the development. It was believed that homogeneous catalysts showed high catalytic activity but difficult product separation whereas heterogeneous catalysts can be easily separated by simple filtration. Finally, the conclusion and the future outlook in the development of catalysts for cyclic carbonate formation are mentioned.
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•Comprehensive analysis was done to examine the photoluminescent and optical properties of tris(2-benzoylacetophenonate)europium complexes with substituted 1,10-phenanthroline ...derivatives.•Spectroscopic analysis suggested the octacoordinated environment around Eu3+ ion.•Spherical atomic coordinates indicate that the Eu3+ ion is facilitated with six oxygen and two nitrogen atoms of BAP and auxiliary units respectively.•Geometry optimization was done and energies of various frontier molecular orbitals have been estimated.•Emission peak at ∼ 612 nm hold great potential as red emitting materials for designing display devices.
We have synthesized a series of heteroleptic luminescent europium moieties based on 1,10-phenanthroline and its derivatives (L) namely Eu(BAP)3L; BAP = 2-benzoylacetophenone. The structural inspection of complexes was done by several spectroscopic techniques. Energy band gap values of complexes lie in region of semiconductors. Metal-ligand interaction results a notable effect on the η (quantum efficiency) and Ω2 (JO parameters) of the prepared complexes. A detailed explanation about photophysical characteristics of the complexes was studied via theoretical and experimental methods. With the help of LUMPAC, theoretical photophysical properties were calculated and discovered to be in good concurrence with experimental values. The hypersensitive electric dipole peak positioned at 612 nm (5D0→7F2) is reasonable for the red emission. The color coordinates are also situated in the red region of CIE triangle. Therefore, these efficient materials could be utilized as red emanating material in designing various display 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 foremost purpose ...of investigation is to study the impact of substituted neutral ligands on optoelectronic properties of complexes.•Photoluminescence emission spectra specify that fluorinated β-diketone ligand have efficiently sensitized Eu(III) ion via antenna effect.•Red color emanating synthesized materials could found good significance in solid state electronics and OLEDs.
The photophysical and optoelectronic characteristics of a series of ternary europium complexes having general formula Eu(TFNB)3L were estimated in detail. The synthesized octa coordinated complexes have different heteroaromatic ancillary ligand (L) i.e., 1,10-phenanthroline (Phen) derivatives. The synthesized heteroleptic europium complexes were thoroughly characterized by various techniques. Photoluminescence emission spectra specify that β-diketone ligand has efficiently sensitized Eu (III) ion through antenna effect which results in excellent luminescent intensity and long decay time. Most intense peak accredited to 5D0→7F2 is accountable for red luminescence of complexes. By investigating the PL emission data, CIE color coordinates were calculated which indicates that subsequent complexes give emission in red region. The Judd-Ofelt parameters of trivalent europium complexes were calculated and also derived theoretically via computational methods. The higher value of hypersensitive electric dipole Ω2 intensity parameter displays the existence of highly polarizable chemical environment around central metal ion. Red light emanating materials might have found good significance in solid state electronics, flat panel devices and OLEDs.
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•Octacoordinated luminous Dy(III) complexes were synthesized with DPD and 1,10-phenanthroline derivatives.•IR and 1H NMR studies suggest the bonding between organic moieties and Dy3+ ...ion.•Hypersensitive peak around 575 nm corresponding to 4F9/2 → 6H13/2 transition is responsible for yellow emission.•Dysprosium’s conducting and thermally stable complexes demonstrate their use in fabricating OLEDs.
Several luminescent ternary dysprosium complexes were synthesized and examined using diketone ligand 1,3-diphenylprop-1,3-dione (DPD) and various auxiliary ligands. Spectroscopic analysis was carried out to determine the structural and photophysical features of Dy (III) complexes. IR and proton NMR spectroscopic studies suggested the bonding of chelating moieties to the metal ion through oxygen and nitrogen atom. The optical and electronic band gap is evaluated which proposed the conducting behaviour of dysprosium complexes. Upon excitation with UV radiation, three distinct emission peaks of the Dy (III) ion are appeared at about 485 nm (J = 15/2), 575 nm (13/2) and 664 nm (11/2) corresponding to the transitions of type 4F9/2 → 6HJ. The strongest emission peak obtained at ∼ 575 nm is responsible for yellow emission of Dy (III) complexes. The yellow to blue (Y/B) ratio estimated for the transition J = 13/2 / J = 15/2 were found to be in the range of 4.19 – 2.80. The quantum yield was also determined for the Dy (III) complexes which is as: Φ1 = 0.315, Φ2 = 0.261, Φ3 = 0.183, Φ4 = 0.157. The synthesized dysprosium complexes demonstrate luminescence lifetime in decreasing order i.e. 0.600 ms > 0.510 ms > 0.431 ms > 0.323 ms. Furthermore, the chromaticity coordinates also confirm their yellow luminous behavior. These newly synthesized complexes could be utilized for developing systems significant for lighting, OLEDs and displays due to their luminous features.
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•Monometallic heteroleptic complexes of Dy(III) with general formula Dy(Hfodo)3L have been synthesized.•The prepared complexes have been investigated by thermal, spectroscopical and ...electrochemical studies.•Electronic and optical band gap has found to be quite similar and in the range of conducting region.•Yellow luminescence is observed corresponding to 4F9/2→6H13/2 transition which demonstrates the utility of complexes in generation of high-efficiency organic light emitting materials.
A series of ternary complexes of dysprosium tris-β-diketonate was prepared by using phenanthroline and its substituted derivatives as neutral ligands. The complex formation or the coordination mode of organic moieties was analysed by elemental, infrared, proton NMR and UV–Visible analyses. The anhydrous nature of prepared complexes was illustrated by using thermogravimetric and infrared studies. The band gap was also measured which is present in the range of conducting zone. The luminescence characteristics were measured in solid and solution. The complex upon excitation under UV light generates emission in the yellow region which indicates proficient energy transference from coordinated moieties to the central Dy(III) ion. The correlated color temperature (CCT) of Dy(III) complexes has been calculated and found to be ∼ 5000 K which belongs to a cold light region. The contribution of 4F9/2 → 6H13/2 transition (75 %) is highest towards total radiative processes and it might be regarded as an acceptable transition for laser amplification. The prepared complexes of Dy(III) could be utilized in fabricating OLEDs and displays due to their band gap value, large thermal stability and high luminous characteristics.
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•Red emissive complexes with Eu(TFFB)3L stoichiometry were synthesized and investigated by spectroscopic studies.•Red emissive behavior of the complexes was characterized by ...photoluminescence study.•Photophysical characteristics of the mononuclear Eu(III) complexes were analyzed theoretically (JOES) and experimentally.•Probability amplitude distribution and the energy of HOMO and LUMO were estimated through DFT.
Heteroleptic trivalent complexes of europium were prepared on reaction of EuCl3·6H2O, fluorinated 1,3-diketone and 2,2′-bipyridine or its derivatives in the molar ratio of 1:3:1 respectively. Structural analysis of prepared complexes was done via spectral study. Luminescence features of synthesized complexes have been explored by the photoluminescence and decay spectral profile. Strong emission in the red spectral region was observed for Eu3+ ion corresponding to the electric dipole 5D0 → 7F2 hypersensitive transition. The radiative transition probabilities as well as the Judd-Ofelt parameters were computed and discussed. Complexes emit red light in the visible spectrum as illustrated by their CIE color coordinates are essential for creating effective display and lighting devices.
The establishment of conducting network in a polymer matrix is essential for the improvement in electrical conductivity and electromagnetic interference (EMI) shielding performance. Here, we report ...the fabrication of nanocomposites comprising polyamideimide and multiwalled carbon nanotubes (MWCNTs) (from 0.5 to 5.0 wt%). The effect of MWCNTs on electrical conductivity, morphology, and EMI shielding behavior has been examined. The morphology of nanocomposites was investigated by scanning electron microscope and x‐ray diffraction, which confirms the uniform dispersion of MWCNTs in the matrix. The electrical conductivity increases from 1.4 × 10−12 to 0.145 × 10−4 S/cm by the inclusion of MWCNTs. The composite PACNT‐5 exhibits a good EMI shielding efficiency of −17 dB in the X‐band region by employing only 5.0 wt% of MWCNTs. The incorporation of MWCNTs formed an interconnected conducting network, which boost the transferability of electrons or charge carriers. This work demonstrates a feasible, simple, and effective strategy for the fabrication of potential PAI/MWCNT composites for highly efficient EMI shielding materials.
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•Samarium complexes of the type Sm(TFFB)3L have been synthesized.•The mononuclear complexes were characterized thermally, electrochemically and spectroscopically.•Conducting nature ...and orange-red emission corresponding to electric dipole 4G5/2→6H9/2 transition is observed through absorption and photoluminescence analyses respectively.•The ternary complexes might be employed to generate high-efficiency organic light emitting materials as well as a variety of displays.
A series of monometallic Sm(III) complexes have been prepared with trifluorinated β-diketone and N-donor Lewis bases. The structure of the complexes was characterized by spectroscopic techniques. Electrochemical and photophysical properties affirmed the conducting nature of the prepared complexes. In the absorption spectral profile of complexes the broad ligand dependent band has appeared due to absorption by chelating moiety. The emission profile of the complexes demonstrated peaks centred on Sm(III) ion which is corresponding to 4H5/2 to 6HJ transition. Synthesized complexes show emission peak at ∼ 648 nm corresponding to the 4G5/2→6H9/2 transition is responsible for the orange-red emissive character of Sm(III) complexes. Also, the colorimetric analysis supports the outcomes of photoluminescence study and confirmed the luminescent nature of prepared Sm(III) complexes. These synthesized materials owing to their conductive and emissive nature could be useful in preparing display devices.
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•Synthesized a set of terbium 1,3-diketonates (TFDH) and Bpy derivatives as auxiliary ligands.•Analysed photoluminescent parameters to observe the ligand-controllable luminescence of ...complexes.•The intra molecular energy transfer (T1 → 5D4) is the main channel for enhanced luminescence.•High thermal stability, redox behaviour and optical properties suggested their semiconducting applications.
Mononuclear heteroleptic green emissive Tb(III) complexes were synthesized utilizing 1,3-diketone and N-based bidentate auxiliary ligands. The structural and photoluminescence characteristics were analyzed employing various spectroscopic and analytical techniques. Band gap values obtained from optical and cyclovoltammetric studies were found in good alignment with each other, illustrating their semiconducting behavior and thereby their potential applications in fabrication of photocells and photovoltaic. The photoluminescent spectra of T1 – T4 complexes exhibited distinct peaks at about 491, 547, 583 and 622 nm. The green emission in these complexes can be attributed to the emission peak observed at approximately 547 nm, which arises from the 5D4→7F5 transition. The thermal investigation revealed their high thermal stability, which further indicates their potential utilization in display devices.
A series of lanthanide complexes have been synthesized with fluorinated 1,3-diketones and heteroaromatic ancillary moieties. Spectroscopic studies reveal the attachment of the respective lanthanide ...ion to the oxygen site of β-diketone and nitrogen site of auxiliary moieties. The conducting behavior of the complexes is proposed by their optical energy gaps which lie in the range of semiconductors. The emission profiles of the lanthanide complexes demonstrate red and green luminescence owing to the distinctive transitions of Sm
3+
and Tb
3+
ions, respectively. Energy transfer
via
antenna effect clearly reveals the effective transfer of energy from the chromophoric moiety to the Ln
3+
ion. The prepared conducting and luminescent Ln(
iii
) complexes might be employed as the emitting component in designing OLEDs.
A series of lanthanide complexes have been synthesized with fluorinated 1,3-diketones and heteroaromatic ancillary moieties.
