Synthesis, Optical Characterization, and Electrochemical Properties of Isomeric Tetraphenylbenzodifurans Containing Electron Acceptor Groups

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2011-05, Vol.115 (17), p.4157-4168
• Main Authors: Santos-Pérez, Javier, Crespo-Hernández, Carlos E, Reichardt, Christian, Cabrera, Carlos R, Feliciano-Ramos, Ileana, Arroyo-Ramírez, Lisandra, Meador, Michael A
• Format: Article
• Language: English
• Subjects: A: Dynamics, Clusters, Excited States; Benzofurans - chemical synthesis; Benzofurans - chemistry; Electrochemistry; Fluorescence; Molecular Structure; Quantum Theory; Stereoisomerism
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp111174p

Isomeric tetraphenylbenzodifuran systems, benzo[1,2-b:5,4]difuran and benzo[1,2-b:4,5]difuran, containing electron acceptor groups (CF3, CN, and NO2) have been synthesized and studied. Their electronic absorption, fluorescence, two-photon absorption cross sections, and electrochemical properties were investigated. The absorption and emission maxima are red-shifted for the linear-conjugated systems in comparison with the corresponding isomer. Dual fluorescence was observed and the existence of a twisted intramolecular charge transfer state was confirmed by low-temperature emission experiments. Wide HOMO−LUMO energy gaps were obtained ranging from 2.53 to 3.28 eV. HOMO levels were found in the energy range of −6.03 to −6.63 eV while LUMO are within −2.55 to −3.52 eV.