File Download
  Links for fulltext
     (May Require Subscription)
Supplementary

postgraduate thesis: Luminescent palladium(II) and platinum(II) complexes with tridentate monoanionic and tetradentate dianionic cyclometallated ligands : structures, photophysical properties and material application

TitleLuminescent palladium(II) and platinum(II) complexes with tridentate monoanionic and tetradentate dianionic cyclometallated ligands : structures, photophysical properties and material application
Authors
Issue Date2013
PublisherThe University of Hong Kong (Pokfulam, Hong Kong)
Citation
Chow, P. [周沛強]. (2013). Luminescent palladium(II) and platinum(II) complexes with tridentate monoanionic and tetradentate dianionic cyclometallated ligands : structures, photophysical properties and material application. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b5106504
AbstractFour structural isomers of platinum(II) complexes with C-deprotonated R-C^N^N-R’ cyclometallated ligands (R-C^N^N-R’ = -extended 6-aryl-2,2’-bipyridine derivatives containing 2-naphthyl, 3-isoquinolinyl, 1-isoquinolinyl or 2-quinolinyl moieties) have been synthesized with their photophysical properties investigated. The one bearing a 3-isoquinolinyl moiety shows the highest emission quantum yield among the four and hence has been extensively modified to give a series of complexes with different ancillary ligands (chloride, iodide, phenoxide, or acetylide). Most of these complexes show vibronic emission (max = 515–644 nm) with high emission quantum yield (up to unity) in degassed CH2Cl2; one of them has been used for OLED fabrication and shows a maximum EQE of 8.15 % with current efficiency of 25 cd A–1. The photocatalytic properties of these derivative complexes for oxidative tertiary amine functionalization have also been examined. Several highly robust and emissive platinum(II) complexes supported by two types of tetradentate O^N^C^N ligand systems (Φem up to 0.99; Td up to 520 ℃) have been synthesized and show different emission energies (λmax = 482–561 nm). Most of them exhibit excimeric emission in solution state at room temperature which are dependent on the modifications on the tetradentate O^N^C^N ligands. DFT/TDDFT calculations reveal that the metal complex showing the most intense excimeric emission possesses an excimeric excited state with a localized structure, which is unusual for these classes of platinum(II) complexes. Based on this finding, WOLED (ηL(max) = 71.0 cd/A, ηp(max) = 55.8 lm/W, ηExt = 16.5 %, CIE = 0.33, 0.42, CRI = 77) and WPLED (ηL(max) = 17.0 cd/A, ηp(max) = 9.1 lm/W, ηExt = 9.7 %, CIE = 0.43, 0.45, CRI = 78) based on this complex have been fabricated with high efficiency achieved. Palladium(II) complexes containing C-deprotonated R-C^N^N-R’ cyclometallated and pentafluorophenylacetylide ligands exhibit phosphorescence in both solid state and fluid solutions at room temperature with some of them exhibiting aggregation-induced emission (AIE). These complexes have been applied as photosensitizers in light-induced oxidative functionalization of secondary and tertiary benzylic amines as well as in light-induced hydrogen production, with a maximum of 175 turnovers for hydrogen produced. Palladium(II) complexes containing two types of tetradentate dianionic O^N^C^N ligand systems (Systems 1 and 2) have been prepared and show constrasting photophyical properties. A full scale time-resolved spectroscopic analysis has been done on some of these complexes and a platinum(II) analogue. These complexes are found to have similar excited state decay pathway( 〖S_1〗^i→〖S_1〗^f→T) with ΦISC of about unity. The emission efficiency of System 2 complexes is superior to that of System 1 complexes, which is ascribed to the suppression of excited state distortion on the basis of the results of DFT calculations. A lower radiative decay rate of System 2 palladium(II) complexes relative to the platinum(II) analogue has been found, which could be due to their lower spin-orbit coupling constant. One of the palladium(II) complexes has been applied in vacuum-deposited OLEDs with maximum current density, power efficiency and EQE of 20.0 cd A^(-1), 13.6 lm W^(-1) and 7.4 % respectively. In addition, applications of these palladium(II) complexes as photosensitizers for oxidation of secondary amines have been examined.
DegreeDoctor of Philosophy
SubjectMetal complexes
Platinum compounds
Dept/ProgramChemistry
Persistent Identifierhttp://hdl.handle.net/10722/193416

 

DC FieldValueLanguage
dc.contributor.authorChow, Pui-keong-
dc.contributor.author周沛強-
dc.date.accessioned2014-01-06T23:09:12Z-
dc.date.available2014-01-06T23:09:12Z-
dc.date.issued2013-
dc.identifier.citationChow, P. [周沛強]. (2013). Luminescent palladium(II) and platinum(II) complexes with tridentate monoanionic and tetradentate dianionic cyclometallated ligands : structures, photophysical properties and material application. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b5106504-
dc.identifier.urihttp://hdl.handle.net/10722/193416-
dc.description.abstractFour structural isomers of platinum(II) complexes with C-deprotonated R-C^N^N-R’ cyclometallated ligands (R-C^N^N-R’ = -extended 6-aryl-2,2’-bipyridine derivatives containing 2-naphthyl, 3-isoquinolinyl, 1-isoquinolinyl or 2-quinolinyl moieties) have been synthesized with their photophysical properties investigated. The one bearing a 3-isoquinolinyl moiety shows the highest emission quantum yield among the four and hence has been extensively modified to give a series of complexes with different ancillary ligands (chloride, iodide, phenoxide, or acetylide). Most of these complexes show vibronic emission (max = 515–644 nm) with high emission quantum yield (up to unity) in degassed CH2Cl2; one of them has been used for OLED fabrication and shows a maximum EQE of 8.15 % with current efficiency of 25 cd A–1. The photocatalytic properties of these derivative complexes for oxidative tertiary amine functionalization have also been examined. Several highly robust and emissive platinum(II) complexes supported by two types of tetradentate O^N^C^N ligand systems (Φem up to 0.99; Td up to 520 ℃) have been synthesized and show different emission energies (λmax = 482–561 nm). Most of them exhibit excimeric emission in solution state at room temperature which are dependent on the modifications on the tetradentate O^N^C^N ligands. DFT/TDDFT calculations reveal that the metal complex showing the most intense excimeric emission possesses an excimeric excited state with a localized structure, which is unusual for these classes of platinum(II) complexes. Based on this finding, WOLED (ηL(max) = 71.0 cd/A, ηp(max) = 55.8 lm/W, ηExt = 16.5 %, CIE = 0.33, 0.42, CRI = 77) and WPLED (ηL(max) = 17.0 cd/A, ηp(max) = 9.1 lm/W, ηExt = 9.7 %, CIE = 0.43, 0.45, CRI = 78) based on this complex have been fabricated with high efficiency achieved. Palladium(II) complexes containing C-deprotonated R-C^N^N-R’ cyclometallated and pentafluorophenylacetylide ligands exhibit phosphorescence in both solid state and fluid solutions at room temperature with some of them exhibiting aggregation-induced emission (AIE). These complexes have been applied as photosensitizers in light-induced oxidative functionalization of secondary and tertiary benzylic amines as well as in light-induced hydrogen production, with a maximum of 175 turnovers for hydrogen produced. Palladium(II) complexes containing two types of tetradentate dianionic O^N^C^N ligand systems (Systems 1 and 2) have been prepared and show constrasting photophyical properties. A full scale time-resolved spectroscopic analysis has been done on some of these complexes and a platinum(II) analogue. These complexes are found to have similar excited state decay pathway( 〖S_1〗^i→〖S_1〗^f→T) with ΦISC of about unity. The emission efficiency of System 2 complexes is superior to that of System 1 complexes, which is ascribed to the suppression of excited state distortion on the basis of the results of DFT calculations. A lower radiative decay rate of System 2 palladium(II) complexes relative to the platinum(II) analogue has been found, which could be due to their lower spin-orbit coupling constant. One of the palladium(II) complexes has been applied in vacuum-deposited OLEDs with maximum current density, power efficiency and EQE of 20.0 cd A^(-1), 13.6 lm W^(-1) and 7.4 % respectively. In addition, applications of these palladium(II) complexes as photosensitizers for oxidation of secondary amines have been examined.-
dc.languageeng-
dc.publisherThe University of Hong Kong (Pokfulam, Hong Kong)-
dc.relation.ispartofHKU Theses Online (HKUTO)-
dc.rightsCreative Commons: Attribution 3.0 Hong Kong License-
dc.rightsThe author retains all proprietary rights, (such as patent rights) and the right to use in future works.-
dc.subject.lcshMetal complexes-
dc.subject.lcshPlatinum compounds-
dc.titleLuminescent palladium(II) and platinum(II) complexes with tridentate monoanionic and tetradentate dianionic cyclometallated ligands : structures, photophysical properties and material application-
dc.typePG_Thesis-
dc.identifier.hkulb5106504-
dc.description.thesisnameDoctor of Philosophy-
dc.description.thesislevelDoctoral-
dc.description.thesisdisciplineChemistry-
dc.description.naturepublished_or_final_version-
dc.identifier.doi10.5353/th_b5106504-
dc.date.hkucongregation2013-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats