Scale-up chemical synthesis of thermally-activated delayed fluorescence emitters based on the dibenzothiophene-S,S-dioxide core

We report a procedure to linearly scale-up the synthesis of 2,8-bis(3,6-di-tert-butyl-9H-carbazol-9-yl)dibenzothiophene-S,S-dioxide (compound 4) and 2,8-bis(10H-phenothiazin-10-yl)dibenzothiophene-S,S-dioxide (compound 5) using Buchwald-Hartwig cross-coupling reaction conditions. In addition, we demonstrate a scaled-up synthesis of all non-commercially available starting materials that are required for the amination crosscoupling reaction. In the present article, we provide the detailed synthetic procedures for all of the described compounds, alongside their spectral characterization. This work shows the possibility to produce organic molecules for optoelectronic applications on a large scale, which facilitates their implementation into real world devices

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

The aim of this review is to give an update on current progress in the synthesis, properties and applications of thiophene-based conjugated systems bearing tetrathiafulvalene (TTF) units. We focus mostly on the synthesis of poly- and oligothiophenes with TTF moieties fused to the thiophene units of the conjugated backbone either directly or via a dithiin ring. The electrochemical behaviour of these materials and structure–property relationships are discussed. The study is directed towards the development of a new type of organic semiconductors based on these hybrid materials for application in organic field effect transistors and solar cells

The role of structural and electronic factors in shaping the ambipolar properties of donor-acceptor polymers of thiophene and benzothiadiazole

The influence of different thiophene donor units on electrochemical and spectroscopic properties of benzothiadiazole based donor–acceptor π-conjugated organic materials is studied. Two different structure modification vectors of the donor units are being considered – one addressing the intermolecular interactions through off-conjugation side chain architecture, and the other focusing on intramolecular interactions tuned by in-conjugation substituents. Electrochemical and simultaneous in situ EPR-UV-Vis-NIR spectroelectrochemical studies of the oxidative (p-) and reductive (n-) doping processes, which are responsible for the optoelectronic properties of these materials, revealed their disparate course and dissimilar effects of redox reactions of the conjugated π-bond. While p-doping prevalent species were found to comprise intensively interacting spin bearing and spinless charge carriers, the n-doping state was found to involve only one type of negatively charged carrier, with spin carrying species being selectively generated at due cathodic potentials. No spin pairing of these negative polarons was observed with their increasing population behaving like a collection of localised charge carriers. Qualitative and quantitative comparisons between the p- and n-doping carrier populations provided independent support for the spin pairing phenomena of positive charge carriers. Steric effects of varying alkyl side chain substitution have demonstrated predominant impact on the electrochemical properties of investigated polymers, and, thereto related, stability of n-doped state, while mesomeric effects of different 3,4-ethylenechalcogenide thiophene functionalities have been found to shape the energy level related spectral properties of these polymers, with particular reference to p-doping induced charged states. These findings provide new insights into the factors requiring attention during structure tailoring of donor–acceptor assemblies for organic optoelectronic applications

Electrochromic properties of a poly(dithienylfuran) derivative featuring a redox-active dithiin unit

A teraryl monomer containing a 1,4-dithiin-furan central unit has been synthesised and characterised by single crystal X-ray crystallography. The di(thienyl)furan monomer 11 was successfully polymerised electrochemically and shown to possess a lower electrochemical band gap than its terthiophene analogue (1.97 eV cf. 2.11 eV). The electrochromic properties of this polymer proved to be superior to PEDOT, with fast switching and reversible colour transformation at high colour contrast (CE = 212 cm(2) C-1 cf. 183 cm(2) C-1 for PEDOT at 95% optical switch)

Solution-processable 2,1,3-benzothiadiazole containing compound based on the novel 1-dodecyl-6-dodecoxynaphthyridine-2-one unit for organic field-effect transistors

Small molecule organic semiconductors have well-defined structures and can be used in place of polymers which often show batch-to-batch variation. Many different electron-rich donor and electron-deficient acceptor units have been used to design materials with reduced HOMO-LUMO gaps and improved mobilities. Here we introduce a novel acceptor unit, 1-dodecyl-6-dodecoxynaphthyridine-2-one. This acceptor unit has been used in the synthesis of two novel compounds, with thiophene and 2,1,3-benzothiadiazole (BT) cores. The BT-containing compound shows a narrower HOMO-LUMO gap, broad solid-state absorption and has been applied to organic field-effect transistors, showing a mobility of 0.022 cm2 V−1 s−1 after optimisation of devices using self-assembled monolayers

To bend or not to bend – are heteroatom interactions within conjugated molecules effective in dictating conformation and planarity?

We consider the roles of heteroatoms (mainly nitrogen, the halogens and the chalcogens) in dictating the conformation of linear conjugated molecules and polymers through non-covalent intramolecular interactions. Whilst hydrogen bonding is a competitive and sometimes more influential interaction, we provide unambiguous evidence that heteroatoms are able to determine the conformation of such materials with reasonable predictability

Analisis Framing Pemberitaan Kasus Dugaan Korupsi dan Gaya Hidup Mewah Gubernur Ratu Atut Chosiyah pada “Koran Tempo”

Modus korupsi sesungguhnya merupakan suatu manipulasi jabatan publik untuk keuntungan pribadi. Mereka menggunakan kewenangan menentukan kebijakan publik semata demi kepentingan sendiri. Peran KPK (Komisi Pemberantasan Korupsi) dan BPK ( Badan Pemeriksa Keuangan) dalam hal ini sangat berpengaruh untuk menghentikan laju pertumbuhan korupsi.Penelitian ini dilakukan untuk mengetahui pembingkaian (framing) berita koran Tempo terhadap kasus korupsi yang dilakukan oleh pejabat wanita terkait kasus dugaan korupsi dan gaya hidup mewah Ratu Atut Chosiyah. Dugaan kasus korupsi Ratu Atut banyak dimuat dalam media cetak maupun media televisi. Tempo terkenal keras pada kasus yang mengindikasi adanya praktik korupsi dan melibatkan kepentingan publik yang besar termasuk pejabat dan aparatur Negara. Tempo hingga kini mampu meliput beberapa kasus Atut baik dalam kasus korupsi maupun gaya hidup mewah Atut. Salah satu metode penelitian yang mampu menganalisis bagaimana realitas itu dibentuk dan dikonstruksi oleh media adalah analisis framing. Peneliti menggunakan analisa Framing yang diperkenalkan oleh Pan dan Kosicki. Obyek penelitian adalah pemberitaan kasus dugaan korupsi dan gaya hidup mewah Gubernur Ratu Atut Chosiyah yang muncul pada koran Tempodari tanggal 5 Okober 2013 sampai 13 November 2013.Hasil penelitian menunjukkan bahwa koran Tempo memberikan gambaran pemberitaan dengan menunjukan struktur Sintaksis, Skrip, Tematik, Dan Retoris. Struktr retoris dalam koran Tempo tampak menonjol karena wartawan koran Tempo banyak menggunakan istilah, leksikon, idiom, bahkan gambar karikatur yang dapat menarik perhatian khalayak. Koran Tempo terkenal dengan gaya pemberitaan yang kritis dan tajam serta memiliki volume dan frekuensi berita yang lengkap karena mampu memuat lebih dari satu pemberitaan dengan kasus yang sama dalam satu edisi. Koran Tempo dalam menuliskan pemberitaan tetap mengedepankan objektivitas dan netralitas, karena wartawan Tempo selalu menjaga agar sebuah karya tetap bermutu tinggi dan berpegang teguh pada kode etik. Nilai etika dan pilihan moral pada Tempo sesuai dengan visi Koran Tempo.Redaksi koran Tempo sebagai Perusahaan yang produknya informasi , diharapkan selalu menjaga obyektivitas dalam menyampaikan pemberitaan dengan memperbanyak sumber berita dan terus menerus meningkatkan apresiasi terhadap ide-ide baru, bahasa, dan tampilan visual yang baik sehinggs dapat menampilkan sebuah informasi yang bermutu tinggi dan layak dikonsumsi masyarakat

BODIPY-based conjugated polymers for broadband light sensing and harvesting applications

The synthesis of novel low band-gap polymers has significantly improved light sensing and harvesting in polymer-fullerene devices. Here the synthesis of two low band-gap polymers based on the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene core (BODIPY), and either bis(3,4-ethylenedioxythiophene) (bis-EDOT) or its all-sulfur analogue bis(3,4-ethylenedithiathiophene) (bis-EDTT) are described. The polymers demonstrate ambipolar charge transport and are shown to be suitable for broadband light sensing and solar energy harvesting in solution-processable polymer-fullerene devices

A saturated red color converter for visible light communication using a blend of star-shaped organic semiconductors

Authors would like to acknowledge the EPSRC for financial support for the UP-VLC (EP/K00042X/1). PJS and IDWS also acknowledge Royal Society Wolfson Research Merit Awards.We report a study of blends of semiconducting polymers as saturated red color converters to replace commercial phosphors in hybrid LEDs for visible light communication (VLC). By blending two star-shaped organic semiconductor molecules, we found a near complete energy transfer (> 90% efficiency) from the green-emitting truxene-cored compound T4BT-B to the red-emitting boron dipyrromethene (BODIPY) cored materials. Furthermore, we have demonstrated the capability of these materials as fast color converters for VLC by measuring their intrinsic optical modulation bandwidth and data rate. The measured 3 dB modulation bandwidth of blends (~55 MHz) is more than 10 times higher than commercially available LED phosphors and also higher than the red-emitting BODIPY color converter alone in solution. The data rate achieved with this blend is 20 times higher than measured with a commercially available phosphor based color converter.PostprintPeer reviewe

An ambipolar BODIPY derivative for a white exciplex OLED and cholesteric liquid crystal laser toward multifunctional devices

A new interface engineering method is demonstrated for the preparation of an efficient white organic light-emitting diode (WOLED) by embedding an ultrathin layer of the novel ambipolar red emissive compound 4,4-difluoro-2,6-di(4-hexylthiopen-2-yl)-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (bThBODIPY) in the exciplex formation region. The compound shows a hole and electron mobility of 3.3 × 10–4 and 2 × 10–4 cm2 V–1 s–1, respectively, at electric fields higher than 5.3 × 105 V cm–1. The resulting WOLED exhibited a maximum luminance of 6579 cd m–2 with CIE 1931 color coordinates (0.39; 0.35). The bThBODIPY dye is also demonstrated to be an effective laser dye for a cholesteric liquid crystal (ChLC) laser. New construction of the ChLC laser, by which a flat capillary with an optically isotropic dye solution is sandwiched between two dye-free ChLC cells, provides photonic lasing at a wavelength well matched with that of a dye-doped planar ChLC cell