DESIGN SYNTHESIS & SPECTROSCOP

DESIGN SYNTHESIS & SPECTROSCOP
Author: Charlotte Po
Publisher: Open Dissertation Press
Total Pages: 392
Release: 2017-01-26
Genre: Science
ISBN: 9781361031704
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This dissertation, "Design, Synthesis and Spectroscopic Studies of Amphiphilic Platinum(II) Complexes With Tridentate N-donor Ligands: From Simple Molecules to Supramolecular Assemblies and Nanostructures" by Charlotte, Po, 布珮樂, 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, SYNTHESIS AND SPECTROSCOPIC STUDIES OF AMPHIPHILIC PLATINUM(II) COMPLEXES WITH TRIDENTATE N-DONOR LIGANDS - FROM SIMPLE MOLECULES TO SUPRAMOLECULAR ASSEMBLIES AND NANOSTRUCTURES Submitted by PO Charlotte for the degree of Doctor of Philosophy at The University of Hong Kong in February 2014 Several series of amphiphilic platinum(II) complexes with tridentate N-donor ligands were synthesized and characterized. Their photophysical properties as well as the spectroscopic changes resulting from the supramolecular assemblies of the complexes were studied. Water-soluble platinum(II) bzimpy complexes have been shown to exhibit strong aggregation in water to give highly ordered nanostructures and by structural modification, various morphologies such as spherical and cylindrical micelles, vesicles and bilayer sheets were obtained. The differences in molecular packing and morphology have been found to give rise to an alteration of Pt---Pt interaction and hence a change in MMLCT absorption and MMLCT emission and such changes were utilized as a probe for the morphological transformation. - + Different hydrophilic groups of sulfonate (-SO ), trimethylammonium (-NMe ) and 3 3 triethylene glycol (TEG) were incorporated into the platinum(II) bzimpy complexes to render their water solubility. An interesting aggregation-partial deaggregation-aggregation process has been demonstrated by [Pt{bzimpy(PrSO ) }Cl]K and its alkynyl analogues via a change in the solvent 3 2 composition. A drastic rainbow-like color change from red to yellow to green and blue was observed via the increase in organic solvent content in the aqueous solution of [Pt{bzimpy(PrSO )}Cl]K. The color change and luminescence change were 3 2 monitored by UV-vis absorption and emission studies, and a change in the MMLCT absorption and emission due to the alteration in Pt---Pt interactions during the assembly and disassembly process was observed. Through microscopy studies, the spectroscopic changes were correlated to a morphological transformation from vesicle to rod. The degree of aggregation of the complexes with different hydrophilic groups was compared through their dimerization constant and the inferences of electrostatic interactions on assemblies were investigated through the modulation of salt content of the solution and via co-assembly studies of the highly charged complexes, [Pt{bzimpy(PrSO ) (OPrSO )}Cl]K and [Pt{bzimpy(C H -NMe ) }Cl]Cl . 3 2 3 2 10 20 3 2 3 Through the incorporation of hydrophilic alkynyl ligands, bolaamphiphilic complexes were also synthesized and their aggregation behavior in water was studied. The effect in tuning the hydrophobicity of the complexes was studied by varying the alkyl chain length of the sulfonate-pendant platinum(II) bzimpy (Pt{bzimpy(PrSO ) }) 3 2 complexes and an unexpected shift in the UV-vis absorption and emission was observed due to the formation of aggregates. The thermo-responsive behavior of a TEG-pendant alkynylplatinum(II) bzimpy complex, [Pt{bzimpy(TEG) }{C≡CC H - 2 6 3 (OC H )-3,5}]Cl, in aqueous solution was investigated and on increasing 12 25 2 temperature, a morphological transformation from bilayer sheet to spherical micelles was observed and a large hysteresis

DESIGN SYNTHESIS & FUNCTIONALI

DESIGN SYNTHESIS & FUNCTIONALI
Author: Yu-Lut Leung
Publisher: Open Dissertation Press
Total Pages: 336
Release: 2017-01-26
Genre: Science
ISBN: 9781361028728
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This dissertation, "Design, Synthesis and Functionalization of Luminescent Alkynylplatinum(II) Complexes of Tridentate N-donor Ligands as Building Blocks for Metallofoldamers, Supramolecular Assemblies and Nanostructures" by Yu-lut, Leung, 梁宇律, 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, SYNTHESIS AND FUNCTIONALIZATION OF LUMINESCENT ALKYNYLPLATINUM(II) COMPLEXES OF TRIDENTATE N-DONOR LIGANDS AS BUILDING BLOCKS FOR METALLOFOLDAMERS, SUPRAMOLECULAR ASSEMBLIES AND NANOSTRUCTURES submitted by LEUNG Yu Lut Sammual for the degree of Doctor of Philosophy at The University of Hong Kong in August 2013 A series of dinuclear platinum(II)-containing meta-phenylene ethynylene (mPE) oligomers and binaphthol derivatives of various lengths, end-capped with symmetric or unsymmetric platinum(II) terpyridine units has been synthesized and characterized. In addition, a mononuclear complex with five repeating mPE units has also been synthesized for comparison studies. Dinuclear alkynylplatinum(II) terpyridine complexes with the optimum length of meta-phenylene ethynylene (mPE) units and the binaphthol derivatives have been found to exhibit a strong tendency to fold back onto themselves to form short helical strands through the stabilization of Pt---Pt and  interactions. The steric bulk of the terpyridine ligands and the length of the oligomeric bridge have been found to affect the extent of the intramolecular Pt---Pt interaction that governs the i stabilization of the short helical strand in solution. Their folding properties via Pt---Pt and  stacking interactions have been studied by H NMR, 2D ROESY NMR, electronic absorption, circular dichroism and emission spectroscopies. A series of dinuclear alkynylplatinum(II) terpyridine complexes bridged by the amphiphilic binaphthol backbone bearing two triethylene glycol monomethyl ether (TEG) chains has been synthesized and characterized. Particularly, one of the complexes with the optimum length of the binaphthol derivative has been shown to undergo transverse aggregation arising from the intra- and intermolecular Pt---Pt and  stacking interactions in aqueous solutions. Such hierarchical assembly of helical strands into tubular columns has been studied by electronic absorption, circular dichroism, and emission spectroscopies, as well as electron microscopies. On the other hand, a series of dinuclear alkynylplatinum(II) terpyridine complexes based on the amphiphilic oligo(para-phenylene ethynylene) (OPE) moiety has been synthesized and characterized. Some of the complexes have been shown to self-assemble into various nanostructures from helical fibers to nanotubes, which have been observed in electron microscopies. The supramolecular polymerization process that occurs through non- covalent Pt---Pt and  stacking interactions during self-assembly has also been studied by the NMR and UV-vis absorption spectroscopies. A series of alkynylplatinum(II) complexes with a tridentate pyridine-based N- heterocyclic carbene 2,6-bis(1-butylimidazol-2-ylidenyl)pyridine) ligand, II [Pt (C DEGREESN DEGREESC)(CCR)](PF ), and their chloroplatinum(II) precursor complex, II [Pt (C DEGREESN DEGREESC)Cl)](PF ) have been synthesized and characterized. One of the alkynylplatinum(II) complexes has also been structurally characterized by X-ray ii crystallography. Their electrochemistry, electronic absorption and luminescence properties have been studied. Nanosecond transient absorption (TA) spectroscopy has also been performed to probe the nature of the excited state.

DESIGN & SYNTHESIS OF LUMINESC

DESIGN & SYNTHESIS OF LUMINESC
Author: Suk-Hang Lam
Publisher: Open Dissertation Press
Total Pages: 292
Release: 2017-01-26
Genre: Science
ISBN: 9781361034019
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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

Luminescent Platinum(ii) Complexes Containing Dianionic Tetradentate Ligands Having Mixed Oxygen, Nitrogen and Carbon Donor Atoms and Platinum(ii)-Containing Phosphorescent Polymers

Luminescent Platinum(ii) Complexes Containing Dianionic Tetradentate Ligands Having Mixed Oxygen, Nitrogen and Carbon Donor Atoms and Platinum(ii)-Containing Phosphorescent Polymers
Author: Wai-Yip Tong
Publisher: Open Dissertation Press
Total Pages:
Release: 2017-01-26
Genre:
ISBN: 9781361342602
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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

DESIGN SYNTHESIS & FUNCTIONALI

DESIGN SYNTHESIS & FUNCTIONALI
Author: Yiu-Yan Tam
Publisher: Open Dissertation Press
Total Pages: 334
Release: 2017-01-24
Genre: Science
ISBN: 9781360968452
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This dissertation, "Design, Synthesis and Functionalization of Luminescent Alkynylplatinum(II) Complexes of Tridentate N-donor Ligands as Building Blocks for Metallogelation and Supramolecular Assembly" by Yiu-yan, Tam, 譚耀欣, 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. DOI: 10.5353/th_b4322384 Subjects: Complex compounds - Synthesis Platinum compounds - Synthesis Photochemistry Ligands Colloids