Photophysical and Liquid Crystalline Properties (platinum (II) Complexes) and Luminescent Properties of Third-row Metal Complex PDF Download

Author: 王康為
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Languages : en
Pages : 172

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Author: Wai-Yip Tong
Publisher: Open Dissertation Press
ISBN: 9781361342602
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Languages : en
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This dissertation, "Luminescent Platinum(II) Complexes Containing Dianionic Tetradentate Ligands Having Mixed Oxygen, Nitrogen and Carbon Donor Atoms and Platinum(II)-containing Phosphorescent Polymers: Synthesis, Photophysical Properties and Material Applications" by Wai-yip, Tong, 唐煒燁, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled LUMINESCENT PLATINUM(II) COMPLEXES CONTAINING DIANIONIC TETRADENTATE LIGANDS HAVING MIXED OXYGEN, NITROGEN AND CARBON DONOR ATOMS AND PLATINUM(II)-CONTAINING PHOSPHORESCENT POLYMERS: SYNTHESIS, PHOTOPHYSICAL PROPERTIES AND MATERIAL APPLICATIONS Submitted by TONG WAI YIP for the degree of Doctor of Philosophy at The University of Hong Kong in May 2014 Square planar platinum(II) complexes exhibit rich photophysical properties which are tunable through the structural variation of ligands and can be harnessed for applications in materials science. In this thesis, the great variety of spectroscopic properties of various square planar cyclometalated platinum(II) complexes supported by tetradentate (O DEGREESN DEGREESN DEGREESC and O DEGREESN DEGREESC DEGREESN) and tridentate (C DEGREESN DEGREESN) ligands containing dipyridyl moieties will be highlighted, along with their synthesis, characterization and potential application in organic light emitting diodes (OLEDs). Ind Platinum(II) complexes supported by tetradentate O DEGREESN DEGREESN DEGREESC or O DEGREESN DEGREESN DEGREESC types of ligands (O DEGREESN DEGREESN DEGREESC = 2-(4-(3,5-di-tert-butylphenyl)-6'-phenyl-2,2'- Ind bipyridin-6-yl)phenolate; O DEGREESN DEGREESN DEGREESC = 5,5-dialkyl-2-(6-phenylpyridin-2-yl) indeno[1,2-b]pyridin-9-olate) are emissive in solution at room temperature, with emission maxima tunable from 582 nm to 640 nm and quantum yields up to 0.28. Mechanochromism and the associated luminescence change in [Pt(dihexyl- Ind O DEGREESN DEGREESN DEGREESC)] (Complex 3.6) were found associated with the two different crystal packings revealed by powder X-ray diffraction (PXRD) studies. Fast vapochromic response of [Pt(3-O DEGREESN DEGREESN-2,6-difluoropyridine)] (Complex 3.3) on chloroform or dichloromethane vapours was found to be associated with structural changes in the solid state through PXRD studies. Robust and strongly emissive platinum(II) complexes supported by tetradentate O DEGREESN DEGREESC DEGREESN ligands featuring fused six-five-six membered metallacyclic ring (O DEGREESN DEGREESC DEGREESN = 2-(4-(3,5-di-tert-butylphenyl)-6-(9-(pyridin-2-yl) carbazol-2-yl)pyridin-2-yl)phenol) have been prepared. These platinum(II) complexes are among the most efficient yellow phosphors, with emission maxima ranging from 526 nm to 553 nm and luminescence quantum yields as high as -1 0.47-0.86. A yellow OLED with power efficiency (η ) up to 52 lm W is power demonstrated. In combination with the typical blue emitting iridium(III) 2' bis(4,6-difluorophenyl-pyridinato-N, C ) picolinate (FIrpic), white organic -1 light-emitting diodes (WOLEDs) displayed η up to 61 lm W and reduced power -2 efficiency roll-off at 1000 cd m . Random copolymers with photo-inert backbone poly[(N-vinylcarbazole)-co- ((R-C DEGREESN DEGREESN)Pt)] and poly[(2-(4-tert-butylphenyl)-5-(4-vinylphenyl)-1,3,4- oxadiazole)-co-((R-C DEGREESN DEGREESN)Pt)] (R-C DEGREESN DEGREESN = 3-(6-phenyl-4-(4-vinylphenyl) pyridine-2-yl)-isoquinoline or 3-(4-(4-(dec-9-enyloxy)phenyl)-6-phenylpyridin- 2-yl)isoquinoline) have been synthesized and characterized. Energy transfer between the charge transporting units and emissive (R-C DEGREESN DEGREESN)Pt units was revealed through ICP-MS inve

Author: Dileep Atchyuth Kumar Vezzu
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Category : Platinum compounds
Languages : en
Pages : 291

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The synthesis, structure, and photophysical properties of luminescent platinum (II) complexes with different coordination patterns, (C^C*N^N), (N^C*N), (N^N*C) and (N^N^C) are reported, where "C^N or N^N" denotes a bidentate coordination to the platinum to form a five-membered metallacycle and "C*N" denotes a bidentate coordination to the platinum to form a six-membered metallacycle. Sixteen cyclometalated platinum complexes have been synthesized with different coordination patterns, which include six complexes with tridentate N^C*N cyclometalating ligands (13, 14, 15, 16, 17, and 18), five complexes with N^N*C cyclometalating ligands (19a, 19b, 20a, 20b, and 24), three complexes with N^N^C cyclometalating ligands (21a, 21b, and 29) and two complexes with tetradentate C^C*N^N cyclometalating ligands (33 and 34). The structures of the platinum complexes 13, 15, 16, 18, 19a, 19b, 20a, 21a, 21b, 24, 29, 33, and 39 were determined by single crystal X-ray diffraction. In platinum complexes with five-six membered metallacycle (15, 16, 18, 19a, 19b, 20a, 24, and 39), the square geometry of the complexes is improved when compared to that of platinum complexes with five-five membered metallacycle as the biting angle is increased. The tetradentate coordination (C^C*N^N), square planar geometry of complex 33 are revealed from its X-ray crystal structure. The DFT calculations have been carried out on complexes 13, 14, 15, 16, 17, 18, 33, and 34 to examine the molecular orbital character of the complexes, which are used in interpreting the electronic spectra of the complexes. The photophysical properties of the platinum complexes were studied and a majority of the complexes were highly emissive in solution at room temperature. Complex 13 exhibited the highest quantum yield (65%) among all of the complexes. Self quenching was not observed in a majority of the platinum complexes at lower concentrations. The cytotoxicity (IC50) of the complexes in three lung cancerous cell lines and one prostate cancer cell line were determined by MTT assay. The toxic platinum complexes induced the cell death by triggering apoptosis. The interactions of the platinum complexes with plasmid and calf thymus DNA were studied. Activation of caspase -7, PARP, and p53 were also observed in RV1 and HCC827 cell lines when treated with platinum complexes. Complexes 35, 37 and 38 were more potent than the clinically approved drug, cis-platin.

Author: Faan-Fung Hung
Publisher: Open Dissertation Press
ISBN: 9781361385432
Category :
Languages : en
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This dissertation, "Luminescent Platinum(II), Palladium(II) and Gold(III) Complexes Containing Isocyanide, Alkynyl and N-heterocyclic Carbene Ligands: Synthesis, Photophysical Properties and Material Applications" by Faan-fung, Hung, 孔繁峰, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Several cyclometalated Pt(II) isocyanide complexes containing C-deprotonated C DEGREESN DEGREESC ligands (C DEGREESN DEGREESC = 2,6-diphenylpyridine derivatives) were synthesized. These complexes display orange-red emissions with max at 582-619 nm and quantum yields of up to 26% in CH2Cl2 at room temperature. The incorporation of carbazole/fluorene/thiophene unit(s) to C DEGREESN DEGREESC ligands leads to minimized structural distortion of complexes in their excited states and thereby suppresses non-radiative decay pathways. The high thermal stability (Td >300 C) renders these complexes good candidates as phosphorescent dopants in organic light-emitting diodes (OLEDs). Red-emitting OLEDs with CIE coordinates of (0.650.01, 0.350.01) were fabricated by vacuum deposition, showing a maximum external efficiency of 12%. In addition, well-defined nano/microstructures were obtained from self-assembly of these complexes driven by π∙∙∙π, C-H∙∙∙π and C-H∙∙∙H-C interactions as observed in the crystal structures. Two series of organopalladium(II) alkynyl complexes containing a terpy (terpy = 2,2':6',2''-terpyridine) or C DEGREESN DEGREESC pincer carbene ligand (C DEGREESN DEGREESC = 2,6-bis(1-butylimidazol-2-ylidenyl)pyridine) were prepared. These complexes are non-emissive in solution at room temperature except that the one containing both C DEGREESN DEGREESC and pyrenylacetylide ligands shows phosphorescence (Φ = 0.3%) originating from intraligand state of the acetylide ligand. This could be attributed to the strong -donating N-heterocyclic carbene (NHC) in the pincer ligand that strongly destabilizes d-d state, the population of which provides an efficient non-radiative decay channel. To make comparison between Pd(II) and Pt(II) complexes with the two ligand systems, Pt(II) C DEGREESN DEGREESC alkynyl complexes were also prepared. They are emissive in solution and some display excimer emissions at high concentration (〖10〗 DEGREES(-4)-〖10〗 DEGREES(-3) mol 〖10dm〗 DEGREES(-3)). The X-ray crystal structures of [Pd(L)(CCPh)](〖PF〗_6) (L = terpy and C DEGREESN DEGREESC) revealed one-dimensional chain stacking of complex cations with alternating Pd(II)∙∙∙Pd(II) contacts of about 3.29-3.35 A and π-π interactions of about 3.4 A . Well-defined submicron/nanostructures were obtained from self-assembly of Pd(II) and Pt(II) alkynyl complexes driven by π-π interactions between aromatic moieties and/or metal∙∙∙metal interactions. DFT calculations on the optimized structures of [M(L)(CCPh)]+ (M = Pd(II) and Pt(II)) revealed the existence of metal∙∙∙metal closed-shell interactions. In addition, the complex containing the C DEGREESN DEGREESC ligand exhibits slightly enhanced metal∙∙∙metal interactions and larger "bonding" energy upon dimerization. Furthermore, spin-orbit coupling between singlet and triplet excited states is more effective which promotes rapid intersystem crossing. A new class of cyclometalated Au(III) complexes containing C-deprotonated C DEGREESN ligands (C DEGREESN = 2-phenylpyridine and its derivatives) and cis-chelating bis-NHC ligands was synthesized. These are the first examples of Au(III) complexes supported by cis-chelating bis-NHC ligands. They display emissions in solution under degassed condition at room temperature with &

Author: 朱明新
Publisher: Open Dissertation Press
ISBN: 9781374682672
Category :
Languages : en
Pages :

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This dissertation, "Syntheses, Characterization and Photophysical Properties of Platinum(II) and Gold(I) Complexes Containing Ortho- and Meta-oligo(phenyleneethynylene) Ligands" by 朱明新, Mingxin, Zhu, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled SYNTHESES, CHARACTERIZATION AND PHOTOPHYSICAL PROPERTIES OF PLATINUM(II) AND GOLD(I) COMPLEXES CONTAINING ORTHO- AND META- OLIGO(PHENYLENEETHYNYLENE) LIGANDS Submitted by Zhu Mingxin for the degree of Doctor of Philosophy at The University of Hong Kong in March 2008 Metal complexes containing oligo(phenyleneethynylene) (PE) are of great importance in photophysics and material science. The syntheses, characterizations and photophysical properties of the light-emitting platinum(II) and gold(I) complexes with flexible ortho- and meta-PE and 2,5-diphenyl-1,3,4-oxadiazole ligands were described. Several novel dinuclear terpyridyl platinum(II) complexes with ortho-PE ligands were synthesized and their crystal structures were determined. The t t 2+ t platinum(II) complexes [( Bu tpy)Pt-(ortho-PE)-Pt( Bu tpy)] ( Bu tpy = 4,4′,4″-tri- 3 3 3 tert-butyl-2,2′ 6′,2″-terpyridine) adopted a helical conformation in their crystal structures, and their phosphorescence recorded in acetonitrile/water mixtures shifted to lower energy with enhanced intensity when the water content increased. A hydrophobic folding process was suggested for the complexes with long ortho-PE(n) (n >= 3), and the red-shifted and enhanced phosphorescence was attributed to inter- and intra-molecular π-π interactions. The mononuclear terpyridine and C DEGREESN DEGREESN capped t + platinum(II) complexes [( Bu tpy)Pt-(ortho-PE)] and [(C DEGREESN DEGREESN)Pt-(ortho-PE)] (HC DEGREESN DEGREESN = 6-phenyl-2,2′-bipyridine) were studied for comparison. A series of mononuclear and dinuclear ortho- and meta-PE gold(I) complexes, [(PCy )Au-(ortho-PE)] (PCy = tricyclohexylphosphine), [(PCy )Au-(ortho-PE)- 3 3 3 Au(PCy)], [(PCy )Au-(meta-PE)] and [(PCy )Au-(meta-PE)-Au(PCy)] were 3 3 3 3 synthesized to examine the effect of ortho- and meta-conjugation. A ππ* emission of the PE ligands was switched on at room temperature by the attachment of [Au(PCy )] fragment due to the heavy atom effect. The delayed fluorescence from the ππ* excited states of the PE ligands was observed, and a triplet-triplet annihilation pathway was proposed. The difference in conjugation of para-, ortho- and meta-PE ligation was examined by comparison of the singlet and triplet emission energies of the gold(I) complexes. By extrapolating the plot of the emission energy against the PE chain length in the complex, the triplet emission energies of poly(ortho-PE) and poly(meta-PE) were estimated to be 530 and 470 nm respectively. These complexes together with the reported [Au(PCy )] complexes containing para-PE ligands, constitute a complete class of [Au(PCy )] supported phenyleneethynylene complexes. 2+ New ortho-PE ligands were used as flexible linkers for [Pt(PEt ) ] moieties 3 2 (PEt = triethylphosphine). Three neutral platinum(II) macrocycles with the maximum ring size of 60 atoms were synthesized and their crystal structures were determined, 31 revealing decreased nuclearity when the ortho-PE length increases. The P NMR spectra of [Pt(PEt ) {ortho-PE(5)}] with a rigid conformation at various temperatures 3 2 are consistent with the calculated spectrum of ABX spin system. A series of platinum(II)-bis(triethylphosphine) complexes containing 2,5- diphenyl-1,3,4-oxadiazole moiety were synthesized, and

Author: Rémi Rouquette
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Category :
Languages : en
Pages : 0

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This thesis focuses on the design, synthesis and the photophysical characterisation of luminescent neutral platinum(II) compounds containing a tridentate chromophoric ligand and a monodentate ancillary moiety with different functionalities. Such complexes exhibited drastic changes to their photoluminescence properties upon self-assembly, triggered by the establishment of weak noncovalent p-p stacking and metallophilic interactions. It was demonstrated that these platinum(II) complexes can be covalently attached to silicon and gold substrates but also encapsulated into polymer particles. The self-assembly properties of amphiphilic platinum(II) complexes have also been intensively studied. Understanding the behaviour of one complex in a solvent mixture allowed further investigation into the supramolecular co-assembly of two different platinum(II) complexes. This approach leads to the formation of solvatochromic fibers with specific and reversible phototophysical properties. The investigated compounds and their assemblies were useful for the development of novel functional materials for sensing or stimuli-responsiveness applications.

Author: Pui-Keong Chow
Publisher: Open Dissertation Press
ISBN: 9781361005378
Category : Science
Languages : en
Pages : 502

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This dissertation, "Luminescent Palladium(II) and Platinum(II) Complexes With Tridentate Monoanionic and Tetradentate Dianionic Cyclometallated Ligands: Structures, Photophysical Properties and Material Application" by Pui-keong, Chow, 周沛強, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Four structural isomers of platinum(II) complexes with C-deprotonated R-C DEGREESN DEGREESN-R' cyclometallated ligands (R-C DEGREESN DEGREESN-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 DEGREESN DEGREESC DEGREESN 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 DEGREESN DEGREESC DEGREESN 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 DEGREESN DEGREESN-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 DEGREESN DEGREESC DEGREESN 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〗 DEGREESi→〖S_1〗 DEGREESf→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 ha

Author:
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ISBN:
Category :
Languages : en
Pages : 235

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Author: Wing-Suen Tang
Publisher: Open Dissertation Press
ISBN: 9781361428030
Category :
Languages : en
Pages :

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This dissertation, "Design and Synthesis of Luminescent Metal Polypyridyl Complexes of Platinum(II), Ruthenium(II) and Osmium(II) for Chemosensing and Biological Studies" by Wing-suen, Tang, 鄧詠璇, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled DESIGN AND SYNTHESIS OF LUMINESCENT METAL POLYPYRIDYL COMPLEXES OF PLATINUM(II), RUTHENIUM(II) AND OSMIUM(II) FOR CHEMOSENSING AND BIOLOGICAL STUDIES Submitted by TANG WING SUEN for the degree of Doctor of Philosophy at The University of Hong Kong in November 2006 A series of platinum(II) terpyridyl alkynyl complexes derivatized with basic amino functionalities and crown ether pendants, [Pt(trpy)(C≡C-R)]X (R = - - -C H -N(CH ) -4, X = OTf; R = -C H -N(CH CH OCH ) -4, X = OTf; R = 6 4 3 2 6 4 2 2 3 2 - - -C H -NH-4, X = OTf; R = -C H -N(CH )-4, X = Cl; R = 6 4 2 6 4 3 2 - - -C H -N(CH CH OCH ) -4, X = Cl; R = -C H -NH -4, X = Cl; R = -B15C5, X 6 4 2 2 3 2 6 4 2 - - = OTf; R = -A15C5, X = OTf ) have been synthesized. The X-ray crystal structure of [Pt(trpy){C≡CC H -N(CH CH OCH )-4}](OTf) has been 6 4 2 2 3 2 determined. The lowest energy absorption of the complexes except [Pt(trpy)(C≡CB15C5)](OTf) were tentatively assigned to originate from a π(C≡C) → π*(trpy) ligand-to-ligand charge transfer (LLCT) transition mixed with some metal-to-ligand charge transfer (MLCT) contribution. The ion-binding and pH dependent properties have also been studied. Their photophysical and spectroscopic properties were shown to be dependent on pH and selected metal ions, and their colorimetric and luminescence chemosensing properties were described. Another series of platinum(II) terpyridyl alkynyl complexes, t - [Pt( Bu trpy)(C≡C-R)]X [R = -C H -NH -4, X = OTf; R = -C H -NCS-4, X = 3 6 4 2 6 4 - - - OTf; R =-C H -NHCOCH I-4, X = OTf; R = -UH-5 (UH = Uracil), X = Cl; 6 4 2 -UMe-5, X = OTf (UMe = 1,3-dimethyluracil)] have been successfully synthesized and characterized. The X-ray crystal structures of t t [Pt( Bu trpy)(C≡C-C H-NCS-4)](OTf), [Pt( Bu trpy)(C≡C-UH-5)]Cl and 3 6 4 3 [Pt( Bu trpy)(C≡C-UMe-5)](OTf) have been determined. Their photophysical and electrochemical behaviour, together with their protein labeling and DNA binding studies, have also been studied. The emission of the complexes in solution at room temperature has been tentatively assigned as originated from a dπ(Pt) → π*( Bu trpy) triplet MLCT excited state. The 77 K butyronitrile glass displayed dual luminescence which were assigned to originate from an intraligand (IL) phosphorescence of the terpyridine ligand and a dπ(Pt) → t 3 t π*( Bu trpy) MLCT phosphorescence. The [Pt( Bu trpy)(C≡C- 3 3 C H-NHCSNH-4)](OTf)-HSA and [Pt( Bu trpy)(C≡C-C H -NHCOCH S- 6 4 3 6 4 2 4)](OTf)-HSA (HSA = human serum albumin) bioconjugates were highly colored and exhibited luminescence in the visible region upon photoexcitation. A series of ruthenium(II) diimine complexes and an osmium(II) diimine complex containing extended π-conjugated ligands, [Ru(bpy) (pmra)](PF ) 2 6 2 [pmra = N-(2-pyridylmethylene)-2-fluorenamine], [Ru(bpy) (pmra)]Cl, 2 2 [Ru(bpy) (pmaa)]Cl [pmaa = N-(2-pyridylmethylene)-2-anthramine], 2 2 [Ru(bpy) (pmpa)]Cl [pmpa = N-(2-pyridylmethylene)-1-pyrenamine], 2 2 [Ru(bpy) (pmfa)]Cl [pmfa = N-(2-pyridylmethylene)-3-fluoranthenamine] 2 2 and [Os(bpy) (pmaa)](PF ), have been synthesized. The lowest energy 2 6 2 absorption bands of the ruthenium(II) complexes w

Author: Suk-Hang Lam
Publisher: Open Dissertation Press
ISBN: 9781361034019
Category : Science
Languages : en
Pages : 292

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This dissertation, "Design and Synthesis of Luminescent Platinum(II) and Gold(III) Complexes With Tridentate Pincer-type Ligands: From Computational Study to Experiments and Application Studies" by Suk-hang, Lam, 林淑恒, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled DESIGN AND SYNTHESIS OF LUMINESCENT PLATINUM(II) AND GOLD(III) COMPLEXES WITH TRIDENTATE PINCER-TYPE LIGANDS - FROM COMPUTATIONAL STUDY TO EXPERIMENTS AND APPLICATION STUDIES Submitted by LAM Suk Hang for the degree of Doctor of Philosophy at The University of Hong Kong in June 2015 Square planar platinum(II) and gold(III) complexes possess unique spectroscopic and photophysical properties which enable them as promising candidates for many applications such as optoelectronic devices and biological sensors. The understanding of the intrinsic properties of these complexes is therefore essential to optimize their performance as well as provide guidance on the molecular design for specific applications. This thesis aims to provide useful insights for the molecular design strategies with the aid of computational studies to tune the electronic properties of these complexes and electroluminescence studies in the fabrication of organic light-emitting devices (OLEDs). Computational studies have been performed to inspect electronic structures and photophysical properties as well as their correlation with the nature of ancillary ligands in the platinum(II) complexes of 1,3-bis(N-alkylbenzimidazol-2′-yl)benzene, [Pt(bzimb)(C≡C-R)], 1,3-bis-hetero-azolylbenzenes, [Pt(N DEGREESC DEGREESN)(C≡C-R)], and pyridine-based N-heterocyclic carbene, [Pt(NHC)(C≡C-R)] . It was found that the emission of the arylalkynylplatinum(II) complexes with pyridine-based N-heterocyclic carbene ligand was originated from the triplet alkynyl-to-tridentate pincer ligand-to-ligand charge transfer excited state mixed with platinum-to-tridentate pincer metal-to-ligand charge transfer character, and the excited state energy was found to be red-shifted according to the increasing π electron-donating ability of the aryl group attached to the alkynyl ligand. On the other hand, the emission energies of the platinum(II) complexes of 1,3-bis(N-alkylbenzimidazol-2′-yl)benzene and 1,3-bis-hetero-azolylbenzenes were found to be dependent on the different electron-donating substituents on the pincer ligands. Calculations have also been performed on the representative alkynylplatinum(II) + + complexes [Pt(trpy)(C≡C-R)] (trpy = 2,2′ 6′,2′′-terpyridine), [Pt(bzimpy)(C≡C-R)] (bzimpy = 2,6-bis(N-alkylbenzimidazol-2′-yl)pyridine) and [Pt(bzimb)(C≡C-R)] as well as alkynylgold(III) complexes [Au(C DEGREESN DEGREESC)(C≡C-R)] (C DEGREESN DEGREESC = 2,6-diphenylpyridine), [Au{C(Np) DEGREESN DEGREESC(Np)}(C≡C-R)] (C(Np) DEGREESN DEGREESC(Np) = 2,6-di(2-naphthyl)pyridine) and [Au(N DEGREESN DEGREESN)(C≡C-R)] (N DEGREESN DEGREESN = 2,6-bis(1H-benzimidazol-2-yl)pyridine) in order to have a better understanding on their nature of the emissive origins as well as the radiative and nonradiative processes. In particular, factors governing the ordering of the triplet excited states and radiative decay rate constants of the emissive state ( ES) have been examined. Their potential energy profiles for the deactivation process from the ES via triplet metal-centered states have also been explored. This study revealed for the first time the potential energy profiles for the thermal deactivation pathway of square planar platinum(II) and gold(III) complexes. In addition to the computational