A new colorimetric and NIR fluorescent chemosensor (1) for Cu(2+) based on BODIPY is reported, displaying a highly sensitive and selective fluorescent enhancement with Cu(2+) among various metal ions, upon excitation at 620 nm in CH(3)CN.

Upon exchanging long chain alkylamine ligands with a carbazole terminated fatty acid as 6-(N-carbazolyl)-hexanoic acid (C6) and 11-(N-carbazolyl) undecanoic acid (C11), efficient photoluminescence (PL) of CdSe/ZnS colloidal quantum dots (QDs) was observed upon excitation in the absorption band of the carbazole moiety at 330 nm. This effect, which occurred both in solution and in a poly(N-vinylcarbazole) (PVK) matrix doped with the QDs, is attributed to sensitization of the QDs by PVK and the ligands. More efficient energy transfer was observed in solution for the shorter ligand (C6) capped QDs, due to a shorter average distance between the donor (carbazole) and the acceptor (QD). The binding of C6 and C11 to the QDs was confirmed by 1H solution nuclear magnetic resonance, which showed line broadening of the carbazole signal due to a decrease of the mobility of the carbazoles upon binding to the QDs compared with the sharp lines observed for the free molecules in solution. In doped PVK films, the significant enhancement of the energy transfer to the QD core could also be related to a better miscibility between the QDs and the PVK as confirmed by optical transmission and confocal microscopy images. In contrast to the experiment in solution, the overall energy transfer in the doped films was found more efficient for QDs capped with C11. To study in more detail the energy transfer between the carbazole moieties and the QDs, time-resolved fluorescence measurements were performed for solutions of C6 and C11, capped QDs and PVK films doped with the QDs. In contrast to the large enhancement of the QD emission indicated by steady-state PL spectra, the latter experiments suggested only a relatively low efficiency (19.6% and 10.8%) for singlet transfer from the carbazole ligands to the QDs. This suggests that the enhancement of the QD emission must be largely due to triplet transfer.

A facile and general two-step method towards 6,12-diaryl-5,11-dihydroindolo[3,2-b]carbazoles has been developed. Hydroiodic acid was an efficient catalyst for the condensation of indole and aromatic aldehydes, and iodine was used as an oxidation reagent to afford symmetrical 6,12-diaryl-5,11-dihydroindolo[3,2-b]carbazoles in moderate to good overall yields.

In this work, the preparation of new S-adenosyl-l-methionine (SAM) analogues for sequence specific DNA labeling is evaluated. Fluorescent cofactors were synthesized and their applicability in methyltransferase based optical mapping is demonstrated.

A new synthetic pathway towards 2,8-difunctionalised indolo[3,2-b]carbazoles was investigated. The presented method offers a short and high yielding route towards 2,8-dibromo-5,11-dihexyl-6,12-diphenyl-indolo[3,2-b]carbazole. It is demonstrated that the latter compound is a versatile building block, enabling the synthesis of a number of previously unreported 5,11-dialkyl-6,12-diphenyl-indolo[3,2-b]carbazoles in moderate to good yields, using Suzuki and Sonogashira cross-coupling reaction. Furthermore it is shown that 2,8-dibromo-5,11-dihexyl-6,12-diphenyl-indolo[3,2-b]carbazole can be easily formylated, giving rise to the 2,8-diformyl-5,11-dihexyl-6,12-diphenyl-indolo-[3,2-b]carbazole. The latter compound was successfully subjected to condensation reactions.