0000000001305269

AUTHOR

Shinto Varghese

showing 10 related works from this author

Green phosphorescence and electroluminescence of sulfur pentafluoride-functionalized cationic iridium(III) complexes

2015

EZ-C acknowledges the University of St Andrews for financial support. We report four cationic iridium(III) complexes [Ir(C^N)2(dtBubpy)](PF6) that have sulfurpentafluoride-modified 1-phenylpyrazole and 2-phenylpyridine cyclometalating (C^N) ligands (dtBubpy = 4,4'-di-tert-butyl-2,2'-bipyridyl). Three of the complexes were characterized by single-crystal X-ray structure analysis. In cyclic voltammetry, the complexes undergo reversible oxidation of iridium(III) and irreversible reduction of the SF5 group. They emit bright green phosphorescence in acetonitrile solution and in thin films at room temperature, with emission maxima between 482–519 nm and photoluminescence quantum yields of up to 7…

Photoluminescencechemistry.chemical_elementChemistry Techniques SyntheticCrystallography X-RayIridiumLigandsPhotochemistryInorganic ChemistryFluorideschemistry.chemical_compoundOrganometallic CompoundsQDIridiumPhysical and Theoretical ChemistryAcetonitrileTrifluoromethylMolecular StructureSulfur CompoundsCationic polymerizationDASElectrochemical TechniquesEquipment DesignQD ChemistrySulfurchemistryLuminescent MeasurementsCyclic voltammetryPhosphorescence
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Luminescence in Crystalline Organic Materials: From Molecules to Molecular Solids

2021

Molecular solidMaterials scienceMoleculePhotochemistryLuminescenceFluorescenceAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsOrganic moleculesAdvanced Optical Materials
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Solid State Luminescence Enhancement in π-Conjugated Materials: Unraveling the Mechanism beyond the Framework of AIE/AIEE

2017

Solid state luminescence enhancement (SLE) of conjugated organic materials has had a great impact in materials science, but a deep understanding has been rather limited to date. Here, we investigate a prototype example of SLE materials, cyano-substituted distyrylbenzene (DCS), by varying systematically and subtly the substitution pattern (inter alia of the position of the cyano-substituent) to give largely different photoresponse in fluid and solid solution as well in the crystalline state. The combination of quantitative (ultra)fast optical spectroscopic techniques, appropriate quantum-chemical methods, and structural (X-ray) data allows us to elucidate and rationalize all details of the S…

Steric effectsChemistryIntermolecular forceSolid-stateNanotechnology02 engineering and technologyConjugated system010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsGeneral EnergyChemical physicsMechanism (philosophy)Radiative transferPhysical and Theoretical Chemistry0210 nano-technologyLuminescenceSolid solutionThe Journal of Physical Chemistry C
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Bent-core liquid crystalline cyanostilbenes: fluorescence switching and thermochromism

2015

et al.

ThermochromismChemistryNDASGeneral Physics and AstronomyQuantum yieldQD ChemistryFluorescenceCrystalLiquid crystalPhase (matter)MoleculePhysical chemistryOrganic chemistryQDEmission spectrumPhysical and Theoretical Chemistry
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Crossed 2D versus Slipped 1D π-Stacking in Polymorphs of Crystalline Organic Thin Films

2019

Polymorphs of organic semiconductors are of great interest as they shed light to structure-property relationships. The full X-ray thin film structure analysis of two polymorphs (B, G) of an important n-type semiconducting dicyano-distyrylbenzene based small molecule (CN-TFPA) is reported. Drastically different structures of the monotropic phases are revealed, that is an uncommon 2D crossed π-stacked arrangement for the B-phase versus a 1D slipped π-stack for G. Both phases exhibit a layered structure in the (100) plane with high structural integrity, driven by the hydrophobic contacts of the terminal CF3 groups; as (100) coincides with the film surface, this allows for exfoliation by scotch…

Materials scienceorganic semiconductorStackingAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsOrganic semiconductorthin film polymorphismCrystallographyorganic optoelectronicsFluorescent materialsfluorescent materialsThin filmtwo-dimensional (2D) charge transportphotophysicsAdvanced Optical Materials
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CCDC 1905199: Experimental Crystal Structure Determination

2019

Related Article: María José Aliaga‐Gosalvez, Nicola Demitri, Michael Dohr, Juan Carlos Roldao, Sang Kyu Park, Sangyoon Oh, Shinto Varghese, Soo Young Park, Yoann Olivier, Begoña Milián‐Medina, Roland Resel, Johannes Gierschner|2019|Adv.Opt.Mater.||1900749|doi:10.1002/adom.201900749

Space GroupCrystallography33'-(14-phenylene)bis{2-[35-bis(trifluoromethyl)phenyl]prop-2-enenitrile}Crystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1053872: Experimental Crystal Structure Determination

2015

Related Article: Nail M. Shavaleev, Guohua Xie, Shinto Varghese, David B. Cordes, Alexandra M. Z. Slawin, Cristina Momblona, Enrique Ortí, Henk J. Bolink, Ifor D. W. Samuel, Eli Zysman-Colman|2015|Inorg.Chem.|54|5907|doi:10.1021/acs.inorgchem.5b00717

(44'-di-t-butyl-22'-bipyridine)-bis(4-(pentafluorosulfanyl)-2-(1H-pyrazol-1-yl)phenyl)-iridium(iii) hexafluorophosphate dichloromethane solvateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1053870: Experimental Crystal Structure Determination

2015

Related Article: Nail M. Shavaleev, Guohua Xie, Shinto Varghese, David B. Cordes, Alexandra M. Z. Slawin, Cristina Momblona, Enrique Ortí, Henk J. Bolink, Ifor D. W. Samuel, Eli Zysman-Colman|2015|Inorg.Chem.|54|5907|doi:10.1021/acs.inorgchem.5b00717

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters(44'-di-t-butyl-22'-bipyridine)-bis(5-(pentafluorosulfanyl)-2-(pyridin-2-yl)phenyl)-iridium(iii) hexafluorophosphateExperimental 3D Coordinates
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CCDC 1905198: Experimental Crystal Structure Determination

2019

Related Article: María José Aliaga‐Gosalvez, Nicola Demitri, Michael Dohr, Juan Carlos Roldao, Sang Kyu Park, Sangyoon Oh, Shinto Varghese, Soo Young Park, Yoann Olivier, Begoña Milián‐Medina, Roland Resel, Johannes Gierschner|2019|Adv.Opt.Mater.||1900749|doi:10.1002/adom.201900749

Space GroupCrystallography33'-(14-phenylene)bis{2-[35-bis(trifluoromethyl)phenyl]prop-2-enenitrile}Crystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1053871: Experimental Crystal Structure Determination

2015

Related Article: Nail M. Shavaleev, Guohua Xie, Shinto Varghese, David B. Cordes, Alexandra M. Z. Slawin, Cristina Momblona, Enrique Ortí, Henk J. Bolink, Ifor D. W. Samuel, Eli Zysman-Colman|2015|Inorg.Chem.|54|5907|doi:10.1021/acs.inorgchem.5b00717

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters(44'-di-t-butyl-22'-bipyridine)-bis(5-(pentafluorosulfanyl)-2-(1H-pyrazol-1-yl)phenyl)-iridium(iii) hexafluorophosphate dichloromethane solvateExperimental 3D Coordinates
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