Abstract
Recently, a family of conducting polyselenophenes was synthesized, and they were shown to have a number of interesting properties. Here we have studied oligoselenophenes, their cation radicals and dications up to the 50-mer (50Se), as well as polyselenophene at the B3LYP/6-31G(d) level of theory, and compared them with the corresponding oligothiophenes. Although the calculations reveal many similarities between oligo- and polyselenophenes and their thiophene-based counterparts, they also show the important differences between those two types of conjugated systems. Oligo- and polyselenophenes have a more quinoid character, lower band gap, and importantly, they are more difficult to twist. The theoretical results suggest that the HOMO-LUMO gap (band gap), bond-length alternation (BLA), and charge distribution in oligo- and polyselenophenes are strongly dependent on inter-ring twisting, yet twisting costs little energy. The inter-ring distances in oligo- and polyselenophenes are shorter than the related distances in oligothiophenes, whereas the bond lengths within the selenophene rings are comparable to those of the corresponding oligothiophenes.
Original language | English |
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Pages (from-to) | 8613-8624 |
Number of pages | 12 |
Journal | Chemistry - A European Journal |
Volume | 15 |
Issue number | 34 |
DOIs | |
Publication status | Published - Aug 24 2009 |
Keywords
- Density functional calculations
- Oligoselenophenes
- Polymers
- Polyselenophenes
- Selenium
ASJC Scopus subject areas
- Catalysis
- Organic Chemistry