کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
177734 | 458998 | 2010 | 7 صفحه PDF | دانلود رایگان |

Derivatives of diphenyl-diketo-pyrrolopyrrole, possessing electron-donating or withdrawing groups in the p-position of the phenyl, were synthesized and studied using optical characterization (absorption, fluorescence, time-resolved fluorescence) and quantum chemical calculation. An increase in absorption coefficient ≥105 dm3 mol−1 cm−1 was observed using electron–donor groups; a bathochromic shift in both absorption and luminescence peaks was observed as a result of increased conjugation. Soluble derivatives were obtained by the introduction of alkyl groups (by N-alkylation) in the central pyrrolopyrrole unit. Calculated phenyl torsion angles using HF and B3LYP methods showed that the loss of molecule planarity reduced the extent of overlap between the π-orbitals of the central pyrrolopyrrole unit and phenyls after N-alkylation. This treatment thus reduced both the bathochromic shift and increased absorption coefficient. The presence of the donor or acceptor groups in itself does not influence molecule planarity.
Journal: Dyes and Pigments - Volume 84, Issue 2, February 2010, Pages 176–182