1189458-67-0Relevant articles and documents
Photoinduced solid-state coloring behavior of boronium complexes
Yoshino, Junro,Sekikawa, Tenku,Hatta, Naoya,Hayashi, Naoto,Higuchi, Hiroyuki
, p. 5489 - 5492 (2016)
Boronium complexes bearing a 9-borabicyclononane framework with a bipyridine-type ligand display photoinduced solid-state coloring behavior. While the identity of the substituents on the boron atom is critical to gain photoresponsive capability, modifying the nitrogen-containing ligand structure and its substituents provides a wide variation in the photoinduced solid color.
Tetramethylammonium Fluoride Alcohol Adducts for SNAr Fluorination
Bland, Douglas C.,Lee, So Jeong,Morales-Colón, Mariá T.,Sanford, Melanie S.,Scott, Peter J. H.,See, Yi Yang
supporting information, p. 4493 - 4498 (2021/06/28)
Nucleophilic aromatic fluorination (SNAr) is among the most common methods for the formation of C(sp2)-F bonds. Despite many recent advances, a long-standing limitation of these transformations is the requirement for rigorously dry, aprotic conditions to maintain the nucleophilicity of fluoride and suppress the generation of side products. This report addresses this challenge by leveraging tetramethylammonium fluoride alcohol adducts (Me4NF·ROH) as fluoride sources for SNAr fluorination. Through systematic tuning of the alcohol substituent (R), tetramethylammonium fluoride tert-amyl alcohol (Me4NF·t-AmylOH) was identified as an inexpensive, practical, and bench-stable reagent for SNAr fluorination under mild and convenient conditions (80 °C in DMSO, without the requirement for drying of reagents or solvent). A substrate scope of more than 50 (hetero) aryl halides and nitroarene electrophiles is demonstrated.
Safety Evaluation of the Copper-Mediated Cross-Coupling of 2-Bromopyridines with Ethyl Bromodifluoroacetate
Yang, Qiang,Cabrera, Pablo J.,Li, Xiaoyong,Sheng, Min,Wang, Nick X.
, p. 1441 - 1447 (2018/10/15)
The potential safety hazards associated with the copper-mediated cross-coupling of 2-bromopyridines with ethyl bromodifluoroacetate were evaluated. Thermal stability evaluation of the postreaction mixture of 50.6 mmol of 2-bromopyridine with 1.3 equiv of ethyl bromodifluoroacetate in the presence of 2.1 equiv of copper in 40 mL of dimethyl sulfoxide (DMSO) indicated a significant decomposition event with an onset temperature of 115.5 °C by accelerating rate calorimetry, which was significantly lower than that of neat DMSO. In contrast, the reaction mixture in N,N-dimethylformamide did not show any exothermic decomposition up to 400 °C by differential scanning calorimetry. Reaction calorimetry evaluation of this reaction in DMSO revealed a heat output (ΔH) of -13.5 kJ and an adiabatic temperature rise (ΔTad) of 129.5 °C, resulting in a maximum temperature of a synthesis reaction (MTSR) of 189.5 °C. The predicted heat of reaction using density functional theory with the BLYP functional was in good agreement with the experimental data. The scope studies with a variety of substituted 2-bromopyridines revealed similar magnitudes of ΔH and ΔTad compared to 2-bromopyridine when reacted at the same concentration. In all of the studied cases, the MTSR was significantly higher than the onset temperature of reaction mixture decomposition, indicating that in the absence of active cooling the system could quickly trigger the decomposition of the reaction mixture, resulting in a runaway reaction.
Isomer Dependence of Efficiency and Charge Recombination in Dye-Sensitized Solar Cells Using Ru Complex Dyes Bearing Halogen Substituents
Chadwick, Nina,Kumar, D. Kishore,Ivaturi, Aruna,Grew, Benjamin A.,Upadhyaya, Hari M.,Yellowlees, Lesley J.,Robertson, Neil
, p. 4878 - 4884 (2015/11/02)
We have synthesised Ru(H2-dcbpy)(N,N′-Y2-bpy)(NCS)2 dyes (where N = 4, 5; Y = F, Cl, Br; N is the position on the bipyridyl ring where the halogen substituent is located) for dye-sensitised solar cells. We show that careful consideration of the position of the substituent, in conjunction with the nature of the substituents, on a bpy ring is important to optimize the solar cells performance. Changing the position (from 4,4′ to 5,5′) along with the nature of the halogen (F, Cl, or Br) substituents were observed to cause changes in the electronic and spectroscopic properties of the dyes as well as influence the recombination rates at the TiO2-dyes-I-/I3- interface affecting the performance of the dyes in DSSCs. Changing the position (from 4,4′ to 5,5′) along with the nature of the halogen (F, Cl, or Br) substituents affects the electronic and spectroscopic properties of the Ru(H2-dcbpy)(N,N′-Y2-bpy)(NCS)2 dyes as well as the recombination rates at the TiO2-dyes-I-/I3- interface hence affecting the performance of the dyes in DSSCs.
