Synthesis, Solid-Phase Reaction, Optical Properties, and Patterning of Luminescent Polyfluorenes

Abstract

The homopolymer of 9,9-di(2-(2-tetrahydropyranyloxy)ethyl)fluorene and copolymers based on 9,9-dihexylfluorene, thiophene, and 3-(2-(2-tetrahydropyranyloxy)ethyl)thiophene repeat units were obtained as patternable blue, green, and blue-green color luminescent polymers. Thermolytic and acidcatalyzed removal of the bulky tetrahydropyran (THP) group from thin solid films of the polymers was investigated. The acid-catalyzed deprotection can be carried out at a significantly lower temperature than thermolytic deprotection in the absence of acid. The effect of the acid-catalyzed deprotection of these polyfluorenes (PFs) on the photoluminescent properties was studied. Prior to deprotection, the polyfluorenes show good optical properties and high emission intensity both in solution and in the solid state. After deprotection, their optical properties were retained and their quantum yields of photoluminescence remained high, but their solubility was reduced due to the presence of hydroxyl groups. The decrease in solubility allows for their spatially controlled deposition using chemically amplified soft lithography.

Photoluminescent Color and Polarized Light Emission Tuning of Fluorene Derivatives Using a Photoreactive H‐Bonded Liquid Crystalline Polymer

“…Another method includes a photolithographic technique, which has achieved precise patterning of the PL imaging of light-emitting materials, but has yet to realize color tuning. [23][24][25][26][27][28] Several lightemitting p-conjugated materials with photo-cross-linkable groups have been investigated. [24][25][26][27] However, color tuning and simultaneous PL patterning of H-bonded photoluminescent materials by adjusting the acidity through external stimuli such as photoirradiation have yet to be explored.…”

Bilayer Approach to Laser‐Induced Thermal Patterning of π‐Conjugated Polymers

“…Experimental 9,9-Dihexylfluorene-2,7-bis(trimethyleneborate) (97%), potassium carbonate (99%), tetrakis(triphenylphosphine)palladium (99%), 5,5 0 -dibromo-2,2-bithiophene (99%) and poly(2-hydroxyethylmethacrylate) were purchased from Sigma-Aldrich Canada Ltd. The NIR dye employed in this study was 2- Synthesis of Poly(9,9-dihexylfluorene-alt-2-(2-thiophen-3-ethoxy) tetrahydropyran)-co-(9,9-dihexylfluorene-alt-bithiophene) (PFT-TT): A solution, degassed with nitrogen, containing 2,5-dibromo-3-(2-(2-tetrahydropyranyl-2-oxy)ethyl)thiophene [13] (0.488g, 1.32 mmol), 9,9-dihexylfluorene-2,7-bis(trimethyleneborate) (0.70g, 1.4 mmol), 5,5 0 -dibromo-2,2 0 -bithiophene (0.023g, 0.071 mmol) and a 3 mL aliquot of an aqueous solution of 2.4 M K 2 CO 3 in THF (15 mL) was prepared and after mixing for several minutes 3 mol % of Pd(PPh 3 ) 4 (0.048 g, 0.0042 mmol) was added to the vial and sealed. The solution was heated for 72 hours at 40 8C.…”

“…For example, negative-tone patterns of thiophene-and fluorene-based polymer films may be obtained by simply exposing selected areas of a tetrahydropyran (THP)-bearing polymer to trace quantities of catalytic acid, whereupon thermal cleavage of the THP group results in an intractable, hydrogen-bonded material. [13,14] More recently, the patterning of similar polymers was reported wherein exposure of a NIR-absorbing dye, directly incorporated into a pCP film (poly(3-(2-(2-tetrahydropyranyloxy) ethyl)thiophene) (PTHPET)), to a 830 nm NIR laser beam induced localized heating that initiated a homolytic deprotection reaction. The latent image formed in the pCP film was further developed with solvent to yield negative-tone patterns of the polymer.…”

Fluorescence “Turn‐On” Patterning With Polymers Having Pendant Triphenylmethane Groups as Fluorophore Precursors

“…Methods for the generation of patterned fluorescence images find great utility in a variety of fields including biotechnology, sensors, molecular switches, imaging, and display areas 1–8. Among the various techniques such as photoirradiation,9–14 inkjet/screen printing,15, 16 vapor deposition,17, 18 and microcontact printing methods19–22 developed to date, the photoirradiation method represents the most popular and practical approach for the fabrication of patterned fluorescence images on a solid support. Photogenerated acid‐cleavable protecting group strategy,23 photoinduced protonation,24–26 photoinduced proton transfer,27 photochromism28 as well as photoinduced formation of fluorophores,29, 30 photoinduced oxidative degradation,31, 32 and rearrangement33 have been actively employed to manipulate the fluorescence of the precursor molecules.…”