Bis(pyridylpyrazolate)platinum(ii): a mechanochromic complex useful as a dopant for colour-tunable polymer OLEDs

Abstract

Electronic Supplementary Information (ESI) available: Schematic representation of pplymer-OLED devices and normalised EL spectra of these devices as a function of bias current. SeeThe photoluminescent and mechanochromic behaviour of bis(3-(3,5-bis(dodecyloxy)phenyl)-(5-pyridin-2yl)pyrazolate)platinum(II) complex PT12, selected from a series of Pt(II) compounds having N,N'-pyridylpyrazolate ligands, has been investigated. The electroluminescent properties of polymer OLEDs based on PT12-doped polyfluorene (PFO) are also described. Addition of PT12 induces the formation of PFO β-phase, a much more ordered phase with enhanced colour stability at high bias and high photoluminescence quantum efficiency. Additionally, the characteristic blue emission of PFO is red-shifted for PT12 concentrations equal or higher than 3%. Depending on the dopant concentration and the applied current, the colour coordinates of these polymer OLEDs undergo a broad shift in the CIE colour space. Besides, through the strategic use of keto defect sites, white-emitting devices can be fabricated with a mere addition of PT12.

A fluorenylidene-acridane that becomes dark in color upon grinding – ground state mechanochromism by conformational change

“…18 , 23 In addition, little attention has been paid to the carrier transport properties of chromic compounds. 4 , 11 , 15 , 24 – 26 …”

Influence of SiO2/TiO2 Nanocomposite on the Optoelectronic Properties of PFO/MEH-PPV-Based OLED Devices

“…There are many advantages that make conjugated polymers attractive as emissive materials in organic light-emitting diode (OLED) devices. Examples of these advantages are low operating voltage, low cost of fabrication, ease of processing and manufacturing, flexibility, capability to build devices with large-area and good solubility in common organic solvents and photothermal stability [1,2,3,4]. OLEDs with various colors can be achieved by several techniques, such as: (i) building bilayers in a tandem diode structure [5,6]; (ii) using a single polymer with multiple functional groups [7,8]; (iii) blending of conjugated polymers [9,10]; (iv) mixing polymers with nanostructured materials [11,12], quantum dots [13,14] and small phosphorescent [15,16] or fluorescent [8,17] molecules.…”

Advanced Functional Luminescent Metallomesogens: The Key Role of the Metal Center

“…Otherwise, these Pt(II) metallomesogens also exhibit electroluminescence properties, and one of them (n = 12) was selected as a prototype to develop polymer OLEDs. 190 The idea, described by the same authors, was taking advantage of the chromic response of the Pt(II) complex and the emission properties of PFO and fluorenone to fabricate workable whiteemitting LEDs (W-OLEDs). Results have shown that in those devices fabricated by doping the PFO matrix with just only 3% of the Pt(II) complex, Pt•••Pt interactions are induced and, concomitantly, the greenish emission of Pt(II) monomers turned on a bright-orange one.…”

“…CIE coordinates of the polymer OLED fabricated with the Pt­(II) metallomesogen 93 ( n = 12) . Reproduced with permission from ref .…”

“…CIE coordinates of the polymer OLED fabricated with the Pt­(II) metallomesogen 93 ( n = 12) . Reproduced with permission from ref . Copyright 2015 The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.…”