2051-85-6Relevant articles and documents
Blue-light-induced processes in a series of azobenzene poly(ester imide)s
Kozanecka-Szmigiel, Anna,Konieczkowska, Jolanta,Szmigiel, Dariusz,Antonowicz, Jerzy,Ma?ecki, Jan,Schab-Balcerzak, Ewa
, p. 177 - 185 (2017)
We report on a series of photoresponsive azobenzene poly(ester imide)s thermally converted from their precursor poly(ester amic acid)s. Thermal properties as well as ability for efficient photoinduced chromophore orientation and polymer mass transport under linearly polarized blue irradiation were investigated, focusing on the effect of azo chromophore location within polymer chain. The amount of chromophore alignment studied in the experiment on photoinduced birefringence differed by a factor of l.5 between the materials. Despite the fact that the generated birefringence was of the same order of magnitude, very large differences in efficiency of surface relief grating formation were seen. Specific features of photoresponsive behaviour of the polymers were shown to correlate with the presence or the absence of intrachain C[sbnd]H?π interaction between azobenzene hydrogen and aromatic imide structure, which was revealed by density functional theory (DFT) calculations. Advantageous chromophore location next to the imide groups for effective light-driven processes was shown.
Azo Derivatives of Pyrocatechol, Resorcinol, and Salicylic Acid as Collectors for Sulfide Ore Flotation
Baigacheva, E. V.,Gogolishvili, V. O.,Gusev, V. Yu.
, p. 1734 - 1744 (2020/02/25)
Heterocyclic and aromatic azo derivatives of pyrocatechol, resorcinol, and salicylic acid have been investigated as collectors for the flotation of sulfide ores. The acid-base properties of the compounds were studied, their solubility in an alkaline solution was determined. It was established that the fixing of reagents on the surface of the ore occurs mainly by the chemical mechanism. Adsorption constants were calculated. It was found that most of the studied reagents exhibit collective properties with respect to sulfide copper—nickel ore. The use of mixtures of azo compounds with potassium butyl xanthogenate leads to an increase in the degree of extraction of nickel and copper, as well as the quality of the concentrates, in comparison with one butyl xanthogenate.
A Photobasic Functional Group
He, Jie,Kimani, Flora W.,Jewett, John C.
supporting information, p. 9764 - 9767 (2015/08/24)
Controlling chemical reactivity using light is a longstanding practice within organic chemistry, yet little has been done to modulate the basicity of compounds. Reported herein is a triazabutadiene that is rendered basic upon photoisomerization. The pH of an aqueous solution containing the water-soluble triazabutadiene can be adjusted with 350 nm light. Upon synthesizing a triazabutadiene that is soluble in aprotic organic solvents, we noted a similar light-induced change in basicity. As a proof of concept we took this photobase and used it to catalyze a condensation reaction.
