(Photo)physical Properties of New Molecular Glasses End-Capped with Thiophene Rings Composed of Diimide and Imine Units

Marzena Grucela-Zajac; Katarzyna Bijak; Slawomir Kula; Michal Filapek; Malgorzata Wiacek; Henryk Janeczek; Lukasz Skorka; Jacek Gasiorowski; Kurt Hingerl; Niyazi Serdar Sariciftci; Natalia Nosidlak; Gabriela Lewinska; Jerzy Sanetra; Ewa Schab-Balcerzak

doi:10.1021/jp501168b

(Photo)physical Properties of New Molecular Glasses End-Capped with Thiophene Rings Composed of Diimide and Imine Units

J Phys Chem C Nanomater Interfaces. 2014 Jun 19;118(24):13070-13086. doi: 10.1021/jp501168b. Epub 2014 May 21.

Affiliations

¹ Institute of Chemistry, University of Silesia , 9 Szkolna Street, 40-006 Katowice, Poland.
² Centre of Polymer and Carbon Materials, Polish Academy of Sciences , 34 M. Curie-Sklodowska Street, 41-819 Zabrze, Poland.
³ Faculty of Chemistry, Warsaw University of Technology , 3 Noakowskiego Street, 00-664 Warsaw, Poland.
⁴ Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, and Center for Surface and Nanoanalytics, Johannes Kepler University Linz , Altenberger Strasse 69, 4040 Linz, Austria ; Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, and Center for Surface and Nanoanalytics, Johannes Kepler University Linz , Altenberger Strasse 69, 4040 Linz, Austria.
⁵ Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, and Center for Surface and Nanoanalytics, Johannes Kepler University Linz , Altenberger Strasse 69, 4040 Linz, Austria.
⁶ Department of Electronics, AGH University of Science and Technology , Al. Mickiewicza 30, 30-059 Krakow, Poland.
⁷ Institute of Physics, Cracow University of Technology , 1 Podchorazych Street, 30-035 Krakow, Poland.
⁸ Institute of Chemistry, University of Silesia , 9 Szkolna Street, 40-006 Katowice, Poland ; Centre of Polymer and Carbon Materials, Polish Academy of Sciences , 34 M. Curie-Sklodowska Street, 41-819 Zabrze, Poland.

Abstract

New symmetrical arylene bisimide derivatives formed by using electron-donating-electron-accepting systems were synthesized. They consist of a phthalic diimide or naphthalenediimide core and imine linkages and are end-capped with thiophene, bithiophene, and (ethylenedioxy)thiophene units. Moreover, polymers were obtained from a new diamine, N,N'-bis(5-aminonaphthalenyl)naphthalene-1,4,5,8-dicarboximide and 2,5-thiophenedicarboxaldehyde or 2,2'-bithiophene-5,5'-dicarboxaldehyde. The prepared azomethine diimides exhibited glass-forming properties. The obtained compounds emitted blue light with the emission maximum at 470 nm. The value of the absorption coefficient was determined as a function of the photon energy using spectroscopic ellipsometry. All compounds are electrochemically active and undergo reversible electrochemical reduction and irreversible oxidation processes as was found in cyclic voltammetry and differential pulse voltammetry (DPV) studies. They exhibited a low electrochemically (DPV) calculated energy band gap (E_g) from 1.14 to 1.70 eV. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels and E_g were additionally calculated theoretically by density functional theory at the B3LYP/6-31G(d,p) level. The photovoltaic properties of two model compounds as the active layer in organic solar cells in the configuration indium tin oxide/poly(3,4-(ethylenedioxy)thiophene):poly(styrenesulfonate)/active layer/Al under an illumination of 1.3 mW/cm² were studied. The device comprising poly(3-hexylthiophene) with the compound end-capped with bithiophene rings showed the highest value of V_oc (above 1 V). The conversion efficiency of the fabricated solar cell was in the range of 0.69-0.90%.