Solid-State Conformation, Molecular Packing, and Electrical and Optical Properties of Processable β-Methylated Sexithiophenes
                                
                                    
                                        作者:Giovanna Barbarella、Massimo Zambianchi、Luciano Antolini、Paolo Ostoja、Piera Maccagnani、Alessandro Bongini、Elisabeth A. Marseglia、Emilio Tedesco、Giuseppe Gigli、Roberto Cingolani                                    
                                    
                                        DOI:10.1021/ja9916512
                                    
                                    
                                        日期:1999.9.1
                                    
                                    Newly synthesized sexithiophenes, di- and tetramethylated at the P-positions, are shown to be soluble and processable compounds, giving single crystals suitable fur X-ray structure determination. The molecular packing was characterized in terms of crystal cohesion and short C-H ... S and C-H ...pi intermolecular distances. In particular, the dimethylated sexithiophene displayed very compressed molecular packing and a thin film field effect transistor, fabricated with this material, was characterized by high charge mobility [2 x 10(-2) cm(2)/(V s)]. The tetramethylated compound crystallizes at room temperature in two different systems and with different conformations. The conformational polymorphs, which are easily interconverted at room temperature, are characterized by different wavelengths of light emission and excitation decay rates.