Langmuir–Blodgett films incorporating an ionic europium complex

Adati, Renata Danielle; Lima, Sergio A. M.; Davolos, Marian Rosaly; Jafelicci, Miguel

doi:10.1016/j.jallcom.2009.08.118

Cited by 6 publications

(4 citation statements)

References 18 publications

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“…However, [Ru(bpy) 2 L ]PF 6 alone is not suitable to deposit LB films since it does not form stable monolayers due to considerable solubility in the aqueous subphase under the experimental conditions. The use of stearic acid mixed with [Ru(bpy) 2 L ]PF 6 serves as a strategy for deposition since it stabilizes the monolayer at the liquid–air interface. − The Langmuir films were assembled with complexes in two distinct oxidation states, Ru II and Ru III , and the films were named Film 1 and Film 2, respectively. The oxidized species was generated by the reaction with hydrogen peroxide and hydrochloric acid (see Experimental Section).…”

Section: Resultsmentioning

confidence: 99%

“…for deposition since it stabilizes the monolayer at the liquid-air interface. [32][33][34][35] The Langmuir films were assembled with complexes in two distinct oxidation states, Ru II and Ru III , and the films were named Film 1 and Film 2, respectively. The oxidized species was generated by the reaction with hydrogen peroxide and hydrochloric acid (see experimental section).…”

Section: Electrochemical Studiesmentioning

confidence: 99%

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Methyl Ester Functionalized Phenalenyl Arene- and Bipyridine–Ruthenium-Based Complexes for Electroactive Langmuir–Blodgett Films

et al. 2019

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We report the synthesis of a new phenalenyl ligand, functionalized with a methyl ester electron withdrawing group, named 9-hydroxy-1-oxo-1H-phenalen-5-methyl carboxylate (L) and the generated complexes [Ru(bpy)2L]PF6 and [(η 6 -C6H6)Ru(L)Cl]. Compounds were characterized by spectroscopic and X-ray diffraction methods and their electrochemical behavior was investigated via cyclic voltammetry and UV-vis spectroelectrochemistry. The one-electron oxidized compounds have unpaired electron located in the phenalenyl ring, as supported by theoretical calculations (DFT) and EPR results. Langmuir-Blodgett (LB) films deposited by [Ru(bpy)2L] 2+/3+ species mixed with stearic acid are electroactive, showing quasi-reversible

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Section: Resultsmentioning

confidence: 99%

Section: Electrochemical Studiesmentioning

confidence: 99%

Methyl Ester Functionalized Phenalenyl Arene- and Bipyridine–Ruthenium-Based Complexes for Electroactive Langmuir–Blodgett Films

et al. 2019

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“…Another approach uses a mixture of nonsurface-active Ln 3+ complexes and classical film-forming substances (for example, stearic acid or arachidic acid) to obtain luminescent LBFs [11][12][13][14][15]. In this case, the CC (for example, Ln(L1)m(L2)n, where L1 is a low-molecularweight β-diketone and L2 is H2O, 1,10-phenanthroline, 2,2′-bipyridine, etc.)…”

Section: Introductionmentioning

confidence: 99%

Features of the Preparation and Luminescence of Langmuir-Blodgett Films Based on the Tb(III) Complex with 3-Methyl-1-phenyl-4-stearoylpyrazol-5-one and 2,2′-Bipyridine

et al. 2022

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In this study, we investigated the effect of terbium ions (Tb3+) on the subphases of the limiting area of the molecule for the complex compound (CC) TbL3∙bipy (where HL is 3-methyl-1-phenyl-4-stearoylpyrazol-5-one and bipy is 2,2’-bipyridine). We examined the Langmuir monolayer and the change in the luminescence properties of TbL3∙bipy-based Langmuir-Blodgett films (LBFs). The analysis of the compression isotherms, infrared, and luminescence spectra of TbL3∙bipy LBFs was performed by varying the concentration of Tb3+ in the subphases. Our results demonstrate the partial dissociation of the CC at concentrations of C(Tb3+) < 5 × 10−4 M.

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“…As the tetrakis complexes are anions, cation derivatives of ammonium salts, such as didodecyldimethylammonium (C 26 H 56 N + ), hexadecyltrimethylammonium (C 19 H 42 N + ), and tetradecyltrimethylammonium (C 17 H 38 N + ), could be used for charge balance. Due to their amphiphilic behaviour, these complexes could be applied, for instance, in the construction of thin films using the Langmuir technique . However, the main challenges concerning the synthesis of those complexes are: (i) how to achieve complexes with high purity levels due to the problem that [Eu(dbm) 4 ] − and [Eu(tfaa) 4 ] − bind to alkaline cations; and (ii) to understand the role of the counter‐ion in luminescence properties.…”

Section: Introductionmentioning

confidence: 99%

Eu³⁺‐tetrakis β‐diketonate complexes for solid‐state lighting application

et al. 2019

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Eu 3+ -β-diketonate complexes are used, for example, in solid-state lighting (SSL) or light-converting molecular devices. However, their low emission quantum efficiency due to water molecules coordinated to Eu 3+ and low photostability are still problems to be addressed. To overcome such challenges, we synthesized Eu 3+ tetrakis complexes based on [Q][Eu(tfaa) 4 ] and [Q][Eu(dbm) 4 ] (Q1 = C 26 H 56 N + , Q2 = C 19 H 42 N + , and Q3 = C 17 H 38 N + ), replacing the water molecules in the tris stoichiometry. The tetrakis β-diketonates showed desirable thermal stability for SSL and, under excitation at 390 nm, they displayed the characteristic Eu 3+ emission in the red spectral region. The quantum efficiencies of the dbm complexes achieved values as high as 51%, while the tfaa complexes exhibited lower quantum efficiencies (28-33%), but which were superior to those reported for the tris complexes. The structures were evaluated using the Sparkle/PM7 model and comparing the theoretical and the experimental Judd-Ofelt parameters. [Q1][Eu(dbm) 4 ] was used to coat a near-UV light-emitting diode (LED), producing a red-emitting LED prototype that featured the characteristic emission spectrum of [Q1][Eu(dbm) 4 ]. The emission intensity of this prototype decreased only 7% after 30 h, confirming its high photostability, which is a notable result considering Eu 3+ complexes, making it a potential candidate for SSL. KEYWORDS dbm, energy transfer, light-emitting diodes, Sparkle/PM7 model, tfaa 1 | INTRODUCTION Lanthanide luminescent complexes are found in numerous applications, for example in luminescent sensors, solid-state lighting (SSL)and light-converting molecular devices (LCMD). [1][2][3] Focusing our attention on SSL, near-UV-to-red downshifting systems based on Eu 3+ complexes and applied as a coat to near-UV LEDs are an exciting alternative to solve the lack of commercial white light-emitting diodes (WLEDs) matching desirable correlated colour temperature (~4500 K) and colour rendering index (> 90) for indoor lighting. [4] However, the main challenges concerning the application of Eu 3+ complexes in SSL are: (i) choice of suitable ligands that exhibit high-energy transfer efficiency between their triplet states and the Ln 3+ emitting level; and (ii) how to overcome the low photo and thermal stability of the complexes. [5] To surpass these challenges, β-diketones such as 1,1,1-trifluoro-2,4-pentanedione (Htfaa) [6] and 1,3-diphenyl-1,3-propanedione (Hdbm) [7] are prominent due to their desirable thermal stability (200°C) and strong π-conjugated molecular moieties that enclose the energy of their triplet state to the Eu 3+ emitting level, enhancing the ion emission quantum efficiency. [8,9] Therefore, Eu 3+ emission quantum efficiency in such complexes is directly influenced by ligand absorption, energy transfer rate from ligand to Eu 3+ , as well as nonradiative losses from the emitting state. [10] /journal/bio 877 d [EuCl 3 ] = 0.054 mol L −1 SCHEME 1 Scheme of the complex syntheses and structural formulae of the rea...

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Langmuir–Blodgett films incorporating an ionic europium complex

Cited by 6 publications

References 18 publications

Methyl Ester Functionalized Phenalenyl Arene- and Bipyridine–Ruthenium-Based Complexes for Electroactive Langmuir–Blodgett Films

Methyl Ester Functionalized Phenalenyl Arene- and Bipyridine–Ruthenium-Based Complexes for Electroactive Langmuir–Blodgett Films

Features of the Preparation and Luminescence of Langmuir-Blodgett Films Based on the Tb(III) Complex with 3-Methyl-1-phenyl-4-stearoylpyrazol-5-one and 2,2′-Bipyridine

Eu³⁺‐tetrakis β‐diketonate complexes for solid‐state lighting application

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Langmuir–Blodgett films incorporating an ionic europium complex

Cited by 6 publications

References 18 publications

Methyl Ester Functionalized Phenalenyl Arene- and Bipyridine–Ruthenium-Based Complexes for Electroactive Langmuir–Blodgett Films

Methyl Ester Functionalized Phenalenyl Arene- and Bipyridine–Ruthenium-Based Complexes for Electroactive Langmuir–Blodgett Films

Features of the Preparation and Luminescence of Langmuir-Blodgett Films Based on the Tb(III) Complex with 3-Methyl-1-phenyl-4-stearoylpyrazol-5-one and 2,2′-Bipyridine

Eu3+‐tetrakis β‐diketonate complexes for solid‐state lighting application

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Eu³⁺‐tetrakis β‐diketonate complexes for solid‐state lighting application