Kinetics and mechanism of the alkaline hydrolysis of guanidine, hexamethylguanidinium perchlorate, and tetramethylurea

Homer, Roger B.; Alwis, K. W.

doi:10.1039/p29760000781

Cited by 19 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, the 1 H and 13 C NMR spectra revealed the presence of dicyclohexylurea (Figures S3 and S4). Based on these results and reported data on the hydrolysis of guanidine scaffolds in basic solution, − it can be concluded that sodium deuteroxide solution not only digests the MOF materials but also hydrolyzes the guanidinium bromide scaffolds that grafted on organic linkers to a water-soluble 2-aminoterephthalate and none-soluble dicyclohexylurea. These observations indirectly confirm the presence of guanidinium scaffolds on organic linkers.…”

Section: Resultsmentioning

confidence: 77%

Multitask Guanidinium Bromide Functionalized Metal–Organic Framework in Chemical Fixation of CO₂ at Low Pressure and Temperature

Shaabani

Mohammadian

Alavijeh

et al. 2019

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

A guanidinium bromide covalently was anchored to a CO2-absorbent metal–organic framework via a two-step postsynthetic modification process and successfully used as a catalyst for the synthesis of cyclic carbonates through cycloaddition of CO2 to epoxides under mild conditions without utilizing any cocatalyst or organic solvent. In this protocol, the synergistic and cooperative effect was anticipated between the catalyst part and the support part to increase the reaction efficiency. Three key factors which are essential for carbon dioxide stabilization reaction were integrated simultaneously in this catalytic system including high CO2 absorption capability of MOF, availability of Lewis acidic centers in MIL-101(Cr) as a cocatalyst, and presence of guanidinium salt as an efficient catalyst. This method demonstrated a high potential for recycling homogeneous catalysts by maintaining their initial performances.

show abstract

Section: Resultsmentioning

confidence: 77%

Multitask Guanidinium Bromide Functionalized Metal–Organic Framework in Chemical Fixation of CO₂ at Low Pressure and Temperature

Shaabani

Mohammadian

Alavijeh

et al. 2019

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…The possibility of autocatalysis in the reaction of [(NH 2 ) 3 C]NO 3 is supported by previous comparisons of the hydrolysis of (NH 2 ) 2 CNH and hexamethylguanidinium chloride . It was concluded that H 2 O attacks the neutral (NH 2 ) 2 CNH rather than the cation .…”

Section: Discussionmentioning

confidence: 74%

Spectroscopy of Hydrothermal Reactions. 4. Kinetics of Urea and Guanidinium Nitrate at 200−300 °C in a Diamond Cell, Infrared Spectroscopy Flow Reactor

et al. 1996

View full text Add to dashboard Cite

Infrared spectroscopy measurements of the kinetics and decomposition pathways of aqueous urea ((NH2)2CO, 200−300 °C, 275 bar) and guanidinium nitrate ([(NH2)3C]NO3, 240−300 °C, 275 bar) are described. A Pt/Ir alloy flow cell with diamond wafer windows was used, and heat and fluid transport models show that isothermal and plug flow conditions exist. The hydrothermolysis of urea was modeled by the conversion of urea to NH4 + + OCN- followed by hydrolysis to CO2 + 2NH3. These reactions are a subset of those for hydrothermolysis of guanidinium nitrate. Decomposition of guanidinium nitrate is catalyzed by the formation of NH3. The reaction scheme involves deprotonation of the guanidinium ion by NH3 to produce neutral guanidine, which hydrolyzes to form urea as the rate-determining step. The subsequent hydrothermolysis chemistry follows that of urea. Thus, although the overall decomposition rate of guanidinium nitrate is slower than that of urea, the Arrhenius parameters for the step for formation of CO2 from guanidinium nitrate and urea are similar [E a ≅ 66 kJ/mol, ln A (s-1) ≅ 19]. Only a small difference in these values is incurred by using a 316 stainless steel−sapphire cell in place of the Pt/Ir−diamond cell. Hence, wall effects appear to be small for this reaction.

show abstract

“…The limited chemical durability of most AEMs is often directly related to the cation appended to the polymer chain . A number of model compound studies have appeared on organic cations in an effort to better understand decomposition pathways and improve alkaline stability (e.g., ammonium, imidazolium, guanidinium, and arylphosphonium). These studies offer a direct means to determine how cations decompose before they are appended to a polymer chain.…”

Section: Introductionmentioning

confidence: 99%

Rapid Analysis of Tetrakis(dialkylamino)phosphonium Stability in Alkaline Media

et al. 2017

View full text Add to dashboard Cite

Hydroxide-stable organic cations are crucial components for ion-transport processes in electrochemical energy systems, and the tetrakis(dialkylamino)phosphonium cation is a promising candidate for this application. These phosphoniums are known to be highly resistant to alkaline media; however, very few investigations have systematically evaluated how these cations decompose in the presence of hydroxide or alkoxide anions. The excellent stability of several tetraaminophosphoniums in 2 M KOH/ CH 3 OH at 80 °C led us to design experiments for the rapid assessment of phosphonium degradation in homogeneous solution and under phase-transfer conditions. The analysis illustrated how substituents around the cation core affect both degradation pathways and rates. β-H elimination and direct attack at the phosphorus atom are the most common degradation pathways observed in an alcoholic solvent, while α-H abstraction and direct attack are observed under phase-transfer conditions (PhCl and 50 wt % NaOH/H 2 O). The collected data provided a relative stability comparison for this family of cations to enable future design improvements and illustrated the utility of using multiple tests for degradation studies.

show abstract

Kinetics and mechanism of the alkaline hydrolysis of guanidine, hexamethylguanidinium perchlorate, and tetramethylurea

Cited by 19 publications

References 0 publications

Multitask Guanidinium Bromide Functionalized Metal–Organic Framework in Chemical Fixation of CO₂ at Low Pressure and Temperature

Multitask Guanidinium Bromide Functionalized Metal–Organic Framework in Chemical Fixation of CO₂ at Low Pressure and Temperature

Spectroscopy of Hydrothermal Reactions. 4. Kinetics of Urea and Guanidinium Nitrate at 200−300 °C in a Diamond Cell, Infrared Spectroscopy Flow Reactor

Rapid Analysis of Tetrakis(dialkylamino)phosphonium Stability in Alkaline Media

Contact Info

Product

Resources

About

Kinetics and mechanism of the alkaline hydrolysis of guanidine, hexamethylguanidinium perchlorate, and tetramethylurea

Cited by 19 publications

References 0 publications

Multitask Guanidinium Bromide Functionalized Metal–Organic Framework in Chemical Fixation of CO2 at Low Pressure and Temperature

Multitask Guanidinium Bromide Functionalized Metal–Organic Framework in Chemical Fixation of CO2 at Low Pressure and Temperature

Spectroscopy of Hydrothermal Reactions. 4. Kinetics of Urea and Guanidinium Nitrate at 200−300 °C in a Diamond Cell, Infrared Spectroscopy Flow Reactor

Rapid Analysis of Tetrakis(dialkylamino)phosphonium Stability in Alkaline Media

Contact Info

Product

Resources

About

Multitask Guanidinium Bromide Functionalized Metal–Organic Framework in Chemical Fixation of CO₂ at Low Pressure and Temperature

Multitask Guanidinium Bromide Functionalized Metal–Organic Framework in Chemical Fixation of CO₂ at Low Pressure and Temperature