Browsing by Subject "Platinum"

Now showing 1 - 4 of 4
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    Bimetallic platinum(II) complexes with bridging di-NHC and N^C^C ligands: synthesis and photophysical properties
    (Royal Society of Chemistry, 2025-10-02) Mariano Paredes; Vivancos Ureña, Ángela; Poveda Otazo, Dionisio; González Herrero, Pablo; Química Inorgánica; Facultades de la UMU::Facultad de Química
    Three new bimetallic Pt(II) compounds of the type [{Pt(dmtppy)}2{μ-(ImMe)2(CH2)n}] [n = 1 (1), 3 (2), 6 (3)], where dmtppy is the dimetalated tridentate N^C^C ligand 2-(4,4’’-dimethyl-[1,1’:3’,1’’-terphenyl]-5’-yl) pyridine and ImMe is N-methylimidazol-N-yl-2-ylidene, have been synthesized in order to explore their ability to form molecular assemblies that affect their luminescence. Restricted rotation around the Pt–carbene bond leads to mixtures of atropisomers, which hinder the growth of single crystals. The com- plexes show efficient emissions with high phosphorescence quantum yields in 2 wt% doped PMMA films at 298 K (PLQY: 73–77%). Significant modifications of their photophysical properties in fluid solution are observed upon variation of the solvent, with the highest efficiencies found in 2-methyltetrahydrofurane (up to 63% quantum yield for complex 3). In the case of complex 1, which contains the shortest linkage, the formation of excimers in MeCN and MeOH causes a significant quenching of the emission, with a substantial decrease in the quantum yield.
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    Data for compounds included in the article "Luminescent Platinum(II) Complexes with Terdentate N∧C∧C Ligands".
    (2023) Poveda Otazo, Dionisio; Vivancos Ureña, Ángela; Bautista, Delia; González Herrero, Pablo; Química Inorgánica; Facultades de la UMU::Facultad de Química
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    Data for compounds included in the article "Synthesis, Luminescence and Electrochemistry of Tris-Chelate Platinum(IV) Complexes with Cyclometalated N-Heterocyclic Carbene Ligands and Aromatic Diimines"
    (2024) Serrano Guarinos, José; Jiménez García, Adrián; Bautista, Delia; González Herrero, Pablo; Vivancos Ureña, Ángela; Química Inorgánica; Facultades de la UMU::Facultad de Química
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    Synthesis, Luminescence, and Electrochemistry of Tris-Chelate Platinum(IV) Complexes with Cyclometalated N-Heterocyclic Carbene Ligands and Aromatic Diimines
    (ACS Publications, 2024-12-19) Serrano Guarinos, José; Jiménez García, Adrián; Bautista, Delia; González Herrero, Pablo; Vivancos Ureña, Ángela; Química Inorgánica; Facultades de la UMU::Facultad de Química
    Dicationic, C2-symmetrical, tris-chelate Pt(IV) com plexes of general formula [Pt(trz)2(N∧N)](OTf)2, bearing two cyclometalated 4-butyl-3-methyl-1-phenyl-1H-1,2,3-triazol-5-yli- dene (trz) ligands and one aromatic diimine [N∧N = 2,2′- bipyridine (bpy, 2), 4,4′-di-tert-butyl-2,2′-bipyridine (dbbpy, 3), 4,4′-dimethoxi-2,2′-bipyridine (dMeO-bpy, 4), 1,10-phenanthro- line (phen, 5), 4,7-diphenyl-1,10-phenanthroline (bphen, 6), dipyrido[3,2-a:2′,3′-c]phenazine (dppz, 7), or 2,3- diphenylpyrazino[2,3-f ][1,10]phenanthroline (dpprzphen, 8)] are obtained through chloride abstraction from [PtCl2(trz)2] (1) using AgOTf in the presence of the corresponding diimine. Complexes 2−4 show long-lived phosphorescence from 3LC excited states involving the diimine ligand, with quantum yields that reach 0.18 in solution and 0.58 in the solid matrix at room temperature for 3. Derivatives with more extended aromatic systems show dual phosphorescent/fluorescent emissions (5, 6) or mainly fluorescence (7, 8) in solution. Comparisons with similar complexes bearing cyclometalated 2-arylpyridines instead of aryl-N-heterocyclic carbenes indicate that the {Pt(trz)2} subunit is crucial to enable efficient emissions from diimine-centered excited states. It is also shown that the introduction of protective bulky substituents on the diimine, such as the tert-butyl groups in 3, is a key strategy to reach higher emission efficiencies. The new compounds represent rare examples of luminescent Pt(IV) complexes that show quasi-reversible one-electron reductions, indicating an unusually high redox stability.