Ashutosh Shrivastava1,Michael Biewer1,Mihaela Stefan1
The University of Texas at Dallas1
Ashutosh Shrivastava1,Michael Biewer1,Mihaela Stefan1
The University of Texas at Dallas1
Pyrrole is the most electron-rich molecule among five-membered heterocyclic molecules like furan, thiophene, and selenophene. These five-membered chalcogenophenes are isoelectronic to each other and have the potential to be utilized for organic electronics. In this study, we have designed and synthesized three different organic compounds containing Di-pyrrole molecules fused with different chalcogenophenes: diethyl 1,7-dihydrofuro[3,2-b:4,5-b']dipyrrole-2,6-dicarboxylate (FDP), diethyl 1,7-dihydrothieno[3,2-b:4,5-b']dipyrrole-2,6-dicarboxylate (TDP), and diethyl 1,7-dihydroselenopheno[3,2-b:4,5-b']dipyrrole-2,6-dicarboxylate (SeDP). The molecular characterization of these compounds was done using <sup>1</sup>H, and <sup>13</sup>C Nuclear Magnetic Resonance (NMR) spectroscopy. The crystal structure determination and phase purity analysis of these compounds were performed using Single Crystal X-Ray Diffraction and Powder X-Ray Diffraction respectively. The XRD analysis reveals that fused rings of these compounds have a planar structure in which two compounds (TDP and SeDP) form dimers and are interacted by N-H●●●O hydrogen bonding. The optical and electrochemical properties were studied using UV-Vis Spectroscopy and Cyclic voltammetry respectively, that displays that these molecules are promising semiconducting candidates for electronic applications. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of these molecules were also calculated by density functional theory (DFT) calculations using Gaussian and are compared with experimental data. Thermogravimetric analysis and Differential Scanning Calorimetry studies show that these compounds are thermally stable (vary in the range of 150-200 °C) and do not have any phase transformation below decomposition temperature. These as-synthesized organic semiconducting molecules will be studied for organic field effect transistor applications.