Andrew C. Grimsdale

Electroluminescent Conjugated Polymers—Seeing Polymers in a New Light

A new exciting interdisciplinary research field has evolved following the discovery that conjugated polymers can emit light when put into light-emitting diodes. A myriad of light-emitting polymers (examples of which are shown below) shining in various colors have been developed through chemical intuition and structural design.

Synthesis of Light-Emitting Conjugated Polymers for Applications in Electroluminescent Devices

School of Chemistry, Bio21 Institute, University of Melbourne, 30 Flemington Road, Victoria 3010, Australia; School of Materials Science and Engineering, Nanyang Technological University, Nanyang Avenue, Republic of Singapore 639798; Institute of Materials Research and Engineering (IMRE) and the Agency for Science, Technology and Research (A*STAR), 3 Research Link, Singapore 117602; and F. Hoffmann-La Roche Ltd., Pharmaceuticals Division, Discovery Chemistry, CH-4070 Basel, Switzerland

Elektrolumineszierende konjugierte Polymere – Polymere erstrahlen in neuem Licht

Ein aufregendes interdisziplinares Forschungsgebiet hat sich aus der Entdeckung entwickelt, das konjugierte Polymere bei Anregung durch Strom Licht emittieren konnen – dies ermoglicht ihre Verwendung in Leuchtdioden. Eine Vielzahl lichtemittierender Polymere (Beispiele siehe unten), deren Farben das gesamte sichtbare Spektrum des Lichts abdecken, wurde durch chemische Intuition und rationales Design entwickelt.

Novel poly(arylene vinylene)s carrying donor and acceptor substituents

New electroluminescent poly(arylene vinylene)s 1 containing electron-withdrawing/donating substituents have been synthesized by the precursor route outlined below. The synthesis of two novel polymers and the evaluation of their photoluminescent and electroluminescent properties in polymer light-emitting diodes (LEDs) are reported.

Precursor route chemistry and optoelectronic properties of poly(pyridine vinylene)

Several soluble precursor routes, involving sulfonium-, methoxy-, and chloro-substituted polymers, have been investigated for the synthesis of poly(pyridine vinylene)(PPyV). The thermal conversions of these precursors to fully conjugated polymer PPyV have been characterised by TGA, FT-IR and UV-VIS spectroscopy in conjunction with microanalysis. Of all the precursors, the chloro-substituted polymer is the most convenient for forming good quality thin films. PPyV fluoresces orange red and has a HOMO-LUMO band gap of 2.2 eV. PPyV has a lower luminescent quantum efficiency compared with its analogue, poly(phenylene vinylene) (PPV), but a higher electron affinity according to CV measurements (with reduction potential of -1.3 V). PPyV was used as an orange red emissive layer in a LED using aluminium as cathode.

Model compounds for novel high electron affinity polymers

Abstract The development of improved polymers for light emitting diodes (LED)s requires fluorescent materials with high electron affinities to act both as emitters and as charge transport materials. In this paper we report the synthesis of novel distyrylpyrazines and distyrylpyrazine- N-oxides as model compounds for novel high electron affinity polymers. The UV-VIS and PL emission spectra demonstate that the emission of these materials can be tuned from blue to red by changing the substituents. Cyclic voltammetry reveals that these compounds possess high electron affinities

A synchrotron diffraction study of two polymorphic forms of 2,5-bis[2-(4-methoxyphenyl)ethenyl]pyrazine

Two polymorphs, alpha and gamma, of the title compound, C(22)H(20)N(2)O(2), have been characterized by means of single-crystal synchrotron X-ray diffraction. In the alpha form, the molecules pack in a herring-bone fashion, linked via weak C-H.N intermolecular interactions (H.N 2.58 A). In the gamma form, the molecules are arranged in nearly planar sheets, which form a network held together by intermolecular hydrogen bonds of the type C-H.O (H. O 2.49 A) and C-H.N (H.N 2.50 A). The stacking distance between the sheets is 3.40 A.

Synthesis of Host Polymers and Guests for Electrophosphorescence

Significant progress has been realized in the design and synthesis of light emitting polymers that emit over the entire visible spectrum. However, up to seventy-five percent of charge recombination events can lead to triplet states that decay non-radiatively. Following the pioneering work in the field of small molecule organic light emitting devices, it has been found that solution processible iridium polymer complexes can be used to harness the wasted triplet energy. In this paper, new results with respect to the electrophosphorescence of solution processible tethered iridium polymer derivatives are presented. Furthermore, our approaches to the design of new high triplet energy conjugated polymer hosts are also reported.