Donor design and modification strategies of metal-free sensitizers for highly-efficient n-type dye-sensitized solar cells

4,7-Dichloro[1,2,5]oxadiazolo[3,4-d]pyridazine 1-oxide

“…Recently, we have shown that [1,2,5]oxadiazolo[3,4-с]pyridine 3-oxide is available via the oxidation of 4-amino-3-nitropyridine with (diacetoxyiodo)benzene (PhI(OAc)2), PIDA or [bis(trifluoroacetoxy)iodo]benzene (PhI(OC(O)CF3)2), PIFA [9]. Herein, we examined 3,6-dichloro-5-nitropyridazin-4-amine 1 in the reaction both with PIDA and PIFA (Scheme 1).…”

“…1,2,5-Chalcogenadiazoles fused with either benzene or heterocyclic rings have been found to be important central building blocks in the synthesis of photovoltaic materials [1][2][3]. Although 2,1,3-benzochalcogenadiazoles have been intensively investigated, their heterocyclic analogues are less known [4,5].…”

“…Within this type of heterocycles, special attention has been paid to their dihalogenated derivatives due to their potential in the synthesis of dyes to the dye-sensitized solar cells (DSSCs) [6]. To the best of our knowledge 4,7-dichloro [1,2,5]thiadiazolo [3,4-d]pyridazine is the only known dihalo [1,2,5]chalcogenadiazolo [3,4-d]pyridazine [7], although no structure confirmation (such as spectral and analytical data or reactivity) was provided. Herein, we report the synthesis of 4,7-dichloro [1,2,5]oxadiazolo[3,4-d]pyridazine 1-oxide.…”

“…To the best of our knowledge 4,7-dichloro [1,2,5]thiadiazolo [3,4-d]pyridazine is the only known dihalo [1,2,5]chalcogenadiazolo [3,4-d]pyridazine [7], although no structure confirmation (such as spectral and analytical data or reactivity) was provided. Herein, we report the synthesis of 4,7-dichloro [1,2,5]oxadiazolo[3,4-d]pyridazine 1-oxide. This compound may be of interest as starting material for the preparation of various photovoltaic materials as well as biologically active compounds since it was shown that the fusion of 1,2,5-oxadiazole N-oxide (furoxan) ring to nitrogen heterocycle can substantially increase the biological activity [8].…”

“…Synthesis of 4,7-dichloro[1,2,5]oxadiazolo[3,4-d]pyridazine 1-oxide 2A solution of 3,6-dichloro-5-nitropyridazin-4-amine (1) (35 mg, 0.16 mmol) and (diacetoxyiodo)benzene (57 mg, 0.17 mmol) in benzene (2 mL) was heated under reflux with stirring for 2 h. The mixture was cooled to room temperature and the solvent was removed under reduced pressure. CH 2 Cl 2 (15 mL) was added to the residue, the organic phase was washed with saturated aqueous NaHCO 3 , and dried overMgSO 4 .…”