Use of 2D Nmr for the Assignment of Structure of 1,3,2-oxazaphospholidin-2-ones

Boulet, Camille A.; Tregear, Scott J.; Hansen, Arnold S.

doi:10.3987/com-91-5745

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The products were bound to the polymer sample, and therefore they could not be extracted for confirmation by other techniques. The chemical shifts of these products were comparable to results reported for reactions of potassium 2,3-butanedione monooximate with GD, which produced 31 P resonances at 38.6 and 38.2 ppm, with a doublet corresponding to the diastereomers . These signals are also close to the ones that were previously assigned to pinacolyl methylphosphonic acid peroxide at 39.1 and 38.2 ppm …”

Section: Resultssupporting

confidence: 84%

“…The relative intensity of the two GD doublets decreased over time, while the single signal belonging to pinacolyl methylphosphonic acid (PMPA) , centered at 25.2 ppm increased. Signals of other products of GD degradation that appeared at 34.3 and 33.8 ppm were tentatively assigned to the reaction of GD with the polymer oxime group, although positive identification could not be made because of the transient nature of these products, since they continued to react and the signals decreased in intensity. The products were bound to the polymer sample, and therefore they could not be extracted for confirmation by other techniques.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Degradation of Chemical Warfare Agents by Reactive Polymers

Bromberg

Schreuder-Gibson

Creasy

et al. 2008

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Nucleophilic hydrolysis of chemical warfare agents (CWA), S-2-(diisopropylamino)ethyl O-ethyl methylphosphonothioate (VX), O-pinacolyl methylphosphonofluoridate (soman, or GD), and isopropyl methylphosphonofluoridate (sarin, or GB) by polyacrylamidoxime (PANOx) and poly(N-hydroxyacrylamide) (PHA) has been demonstrated. The reactive PANOx and PHA were obtained by one-step oximation of polyacrylonitrile and polyacrylamide, respectively. The polymers were converted to their respective oximate salts at pH values greater than the pK a of oximate or amidoximate groups of 7.5 and 10.8, respectively. Although the PANOx and PHA exhibited spontaneous hydrolysis at ambient temperature and humidity, the conversion of the hydroxamate into the unreactive carboxylic groups was insignificant even at prolonged storage, so that the polymers maintained reactivity at ambient conditions. When exposed to ambient air or 100% humidity, the polymers imbibed up to 65 wt % water, which dramatically enhanced the polymer reactivity toward the CWA under study. The half-lives of VX in heterogeneous hydrolysis, which appeared to be pseudo-first-order in the polymer dispersions, were measured to be from 0.093 to 4.3 and 7.7 h in the presence of PANOx and PHA, respectively. The rates of hydrolytic activity of PANOx for VX exhibited a strong dependency on the degree of conversion of the amidoxime to amidoximate groups. The half-life of GB was less than 3 min. Only a minor presence of the toxic VX degradation product, S-[2-(diisopropylamino)ethyl]methylphonothioate (EA-2192), was detected in the course of degradation by the reactive polymers. The efficiency, ease of synthesis, and nontoxic nature of the PANOx and PHA polymers make them attractive materials in decontamination and as components of reactive barriers.

show abstract

Section: Resultssupporting

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Degradation of Chemical Warfare Agents by Reactive Polymers

Bromberg

Schreuder-Gibson

Creasy

et al. 2008

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Due to the influence of the phosphoryl bond, the proton in position 4 in the cis configuration is more deshielded than the one in the trans configuration and its chemical shift can be used for the assignment of the relative configuration. [10][11][12][13] In order to determine the enantioselectivity of the rearrangement, the reaction was repeated starting with the chiral phosphorimidates cis-and trans-(5R)-7b, derived from the chiral (R)-aminoalcohol ((R)-N-1-benzylaminopropan-2-ol) (Scheme 4). After rearrangement, the diastereomers were isolated and separated, and their relative configuration (cis/trans) was determined by 1 H NMR as described before for the racemic compounds.…”

Section: Resultsmentioning

confidence: 99%

Imide–amide rearrangement of oxazaphosphorimidates: studies towards the application to the synthesis of chiral Lewis bases

2004

View full text Add to dashboard Cite

“…As an alternative to traditional moving beds, Svante Inc. (formerly Inventys, Inc.) has developed a process using a rotating reactor that can efficiently separate CO 2 from industrial flue gas (not much information available in the open literature). , A moving bed comprising a rotating bed adsorber (RBA) with combined pressure and temperature swing regeneration mode was proposed and simulated by Gupta et al The RBA consists of disc-shaped adsorbent sheets with parallel passages that are divided into four sections as shown in Figure . At any instant, two of the sections are exposed to flue gas for CO 2 adsorption, while the other two remain in the desorption chamber which consists of a heating section using steam that is maintained under vacuum and a cooling section to cool the adsorbent for the next cycle.…”

Section: Reactor Configurationsmentioning

confidence: 99%

Review on Reactor Configurations for Adsorption-Based CO₂ Capture

Dhoke

Zaabout

Cloete

et al. 2021

Ind. Eng. Chem. Res.

133

View full text Add to dashboard Cite

Adsorption-based CO 2 capture has enjoyed considerable research attention in recent years. Most of the research efforts focused on sorbent development to reduce the energy penalty. However, the use of suitable gas−solid contacting systems is key for extracting the full potential from the sorbent to minimize operating and capital costs and accelerate the commercial deployment of the technology. This paper reviews several reactor configurations that were proposed for adsorptionbased CO 2 capture. The fundamental behavior of adsorption in different gas−solid contactors (fixed, fluidized, moving, or rotating beds) and regeneration under different modes (pressure, temperature, or combined swings) is discussed, highlighting the strengths and limitations of different combinations of gas−solid contactor and regeneration mode. In addition, the estimated energy duties in published studies and current technology readiness level of the different reactor configurations are reported. Other aspects, such as the reactor footprint, the operation strategy, suitability to retrofits, and the ability to operate under flexible loads are also discussed. In terms of future work, the key research need is a standardized techno-economic benchmarking study to calculate CO 2 avoidance costs for different adsorption technologies under standardized assumptions. Qualitatively, each technology presents several strengths and weaknesses that make it impossible to identify a clear optimal solution. Such a standardized quantitative comparison is therefore needed to focus on future technology development efforts.

show abstract

Use of 2D Nmr for the Assignment of Structure of 1,3,2-oxazaphospholidin-2-ones

Cited by 4 publications

References 0 publications

Degradation of Chemical Warfare Agents by Reactive Polymers

Degradation of Chemical Warfare Agents by Reactive Polymers

Imide–amide rearrangement of oxazaphosphorimidates: studies towards the application to the synthesis of chiral Lewis bases

Review on Reactor Configurations for Adsorption-Based CO₂ Capture

Contact Info

Product

Resources

About

Use of 2D Nmr for the Assignment of Structure of 1,3,2-oxazaphospholidin-2-ones

Cited by 4 publications

References 0 publications

Degradation of Chemical Warfare Agents by Reactive Polymers

Degradation of Chemical Warfare Agents by Reactive Polymers

Imide–amide rearrangement of oxazaphosphorimidates: studies towards the application to the synthesis of chiral Lewis bases

Review on Reactor Configurations for Adsorption-Based CO2 Capture

Contact Info

Product

Resources

About

Review on Reactor Configurations for Adsorption-Based CO₂ Capture