57455-05-7Relevant academic research and scientific papers
Degradation of Organic Cations under Alkaline Conditions
You, Wei,Hugar, Kristina M.,Selhorst, Ryan C.,Treichel, Megan,Peltier, Cheyenne R.,Noonan, Kevin J. T.,Coates, Geoffrey W.
supporting information, p. 254 - 263 (2020/12/23)
Understanding the degradation mechanisms of organic cations under basic conditions is extremely important for the development of durable alkaline energy conversion devices. Cations are key functional groups in alkaline anion exchange membranes (AAEMs), and AAEMs are critical components to conduct hydroxide anions in alkaline fuel cells. Previously, we have established a standard protocol to evaluate cation alkaline stability within KOH/CD3OH solution at 80 °C. Herein, we are using the protocol to compare 26 model compounds, including benzylammonium, tetraalkylammonium, spirocyclicammonium, imidazolium, benzimidazolium, triazolium, pyridinium, guanidinium, and phosphonium cations. The goal is not only to evaluate their degradation rate, but also to identify their degradation pathways and lead to the advancement of cations with improved alkaline stabilities.
Imidazolium Cations with Exceptional Alkaline Stability: A Systematic Study of Structure-Stability Relationships
Hugar, Kristina M.,Kostalik, Henry A.,Coates, Geoffrey W.
, p. 8730 - 8737 (2015/07/27)
Highly base-stable cationic moieties are a critical component of anion exchange membranes (AEMs) in alkaline fuel cells (AFCs); however, the commonly employed organic cations have limited alkaline stability. To address this problem, we synthesized and characterized the stability of a series of imidazolium cations in 1, 2, or 5 M KOH/CD3OH at 80 °C, systematically evaluating the impact of substitution on chemical stability. The substituent identity at each position of the imidazolium ring has a dramatic effect on the overall cation stability. We report imidazolium cations that have the highest alkaline stabilities reported to date, >99% cation remaining after 30 days in 5 M KOH/CD3OH at 80 °C.
Phosphonium-functionalized polyethylene: A new class of base-stable alkaline anion exchange membranes
Noonan, Kevin J. T.,Hugar, Kristina M.,Kostalik, Henry A.,Lobkovsky, Emil B.,Abruna, Hector D.,Coates, Geoffrey W.
supporting information, p. 18161 - 18164,4 (2012/12/12)
A tetrakis(dialkylamino)phosphonium cation was evaluated as a functional group for alkaline anion exchange membranes (AAEMs). The base stability of [P(N(Me)Cy)4]+ was directly compared to that of [BnNMe3]+ in 1 M NaOD/CD3OD. The high base stability of [P(N(Me)Cy)4]+ relative to [BnNMe 3]+ inspired the preparation of AAEM materials composed of phosphonium units attached to polyethylene. The AAEMs (hydroxide conductivity of 22 ± 1 mS cm-1 at 22 °C) were prepared using ring-opening metathesis polymerization, and their stabilities were evaluated in 15 M KOH at 22 °C and in 1 M KOH at 80 °C.
Phosphonium-functionalized polyethylene: A new class of base-stable alkaline anion exchange membranes
Noonan, Kevin J. T.,Hugar, Kristina M.,Kostalik, Henry A.,Lobkovsky, Emil B.,Abru?a, Héctor D.,Coates, Geoffrey W.
supporting information, p. 18161 - 18164 (2013/01/15)
A tetrakis(dialkylamino)phosphonium cation was evaluated as a functional group for alkaline anion exchange membranes (AAEMs). The base stability of [P(N(Me)Cy)4]+ was directly compared to that of [BnNMe3]+ in 1 M NaOD/CD3OD. The high base stability of [P(N(Me)Cy)4]+ relative to [BnNMe 3]+ inspired the preparation of AAEM materials composed of phosphonium units attached to polyethylene. The AAEMs (hydroxide conductivity of 22 ± 1 mS cm-1 at 22 °C) were prepared using ring-opening metathesis polymerization, and their stabilities were evaluated in 15 M KOH at 22 °C and in 1 M KOH at 80 °C.
Collision-induced loss of AgH from Ag+ adducts of alkylamines, aminocarboxylic acids and alkyl benzyl ethers leads exclusively to thermodynamically favored product ions
Schaefer, Mathias,Dreiocker, Frank,Budzikiewicz, Herbert
experimental part, p. 278 - 284 (2009/07/11)
The loss of AgH from [M + Ag]+ precursor ions of tertiary amines, aminocarboxylic acids and aryl alkyl ethers is examined by deuterium labeling combined with collision activation (CA) dissociation experiments. It was possible to demonstrate tha
Photolysis of a methanolic solution of benzyl acetate in low acoustic fields
Rykov, S. V.,Skakovskii, E. D.,Murashko, V. L.,Tychinskaya, L. Yu.,Filatova, M. P.
, p. 176 - 177 (2007/10/02)
The influence of low acoustic fields on the photolysis of benzyl acetate in solution was investigated.A change in the contributions of alternative photolysis mechanisms is caused by destruction of solvate shells. -Key words: benzyl acetate, photolysis, acoustic fields.
Photolysis of methanolic solutions of benzyl acetate
Skakovskii, E. D.,Rykov, S. V.,Tychinskaya, L. Yu,Murashko, V. L.,Ogorodnikova, M. M.,et al.
, p. 647 - 650 (2007/10/02)
Photolysis of solutions of benzyl acetate in CD3OD has been studied.As has been established based on the effects of CIDNP and the yields of products, decomposition of the starting compound occurs from both excited singlet and triplet electronic states.The contributions of homolysis and solvolysis to the overall photochemical process have been measured, and the lifetimes of the acetoxy radicals formed have been evaluated.Toluene-d has been shown to be formed mostly by disproportionation of benzyl radicals with hydroxymethyl radicals derived from the solvent molecules.Key words: benzyl acetate; methanol; photolysis; homolysis; solvolysis; CIDNP effects.
