New insight into the reaction mechanism of carbon disulfide hydrolysis and the impact of H2S with density functional modeling

2019 ◽  
Vol 43 (5) ◽  
pp. 2347-2352 ◽  
Author(s):  
Xin Song ◽  
Chi Wang ◽  
Khaled A. M. Gasem ◽  
Kai Li ◽  
Xin Sun ◽  
...  

One-step hydrolysis can easily take place without a catalyst. H2S is beneficial in maintaining the stability of the intermediates.

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1145
Author(s):  
Panagiotis Kanellopoulos ◽  
Aikaterini Kaloudi ◽  
Maritina Rouchota ◽  
George Loudos ◽  
Marion de Jong ◽  
...  

Background: Peptide radioligands may serve as radionuclide carriers to tumor sites overexpressing their cognate receptor for diagnostic or therapeutic purposes. Treatment of mice with the neprilysin (NEP)-inhibitor phosphoramidon was previously shown to improve the metabolic stability and tumor uptake of biodegradable radiopeptides. Aiming to clinical translation of this methodology, we herein investigated the impact of the approved pill Entresto, releasing the potent NEP-inhibitor LBQ657 in vivo, on the stability and tumor uptake of two radiopeptides. Methods: The metabolic stability of [99mTc]Tc-DB4 (DB4, N4-Pro-Gln-Arg-Tyr-Gly-Asn-Gln-Trp-Ala-Val-Gly-His-Leu-Nle-NH2) and [111In]In-SG4 (SG4, DOTA-DGlu-Ala-Tyr-Gly-Trp-Nle-Asp-Phe-NH2) was tested in LBQ657/Entresto-treated mice vs. untreated controls. The uptake in gastrin-releasing peptide receptor (GRPR)-, or cholecystokinin subtype 2 receptor (CCK2R)-positive tumors respectively, was compared between LBQ657/Entresto-treated mice and untreated controls. Results: LBQ657/Entresto treatment induced marked stabilization of [99mTc] Tc-DB4 and [111In]In-SG4 in peripheral mice blood, resulting in equally enhanced tumor uptake at 4 h post-injection. Accordingly, the [99mTc]Tc-DB4 uptake of 7.13 ± 1.76%IA/g in PC-3 tumors increased to 16.17 ± 0.71/17.50 ± 3.70%IA/g (LBQ657/Entresto) and the [111In]In-SG4 uptake of 3.07 ± 0.87%IA/g in A431-CCK2R(+) tumors to 8.11 ± 1.45/9.61 ± 1.70%IA/g. Findings were visualized by SPECT/CT. Conclusions: This study has shown the efficacy of Entresto to notably improve the profile of [99mTc]Tc-DB4 and [111In]In-SG4 in mice, paving the way for clinical translation of this approach.


2013 ◽  
Vol 91 (12) ◽  
pp. 1243-1251 ◽  
Author(s):  
Yong Pan ◽  
Weihua Zhu ◽  
Heming Xiao

The heats of formation (HOFs), energetic properties, strain energies, thermal stability, and impact sensitivity for a series of trinitromethyl- or dinitromethyl-modified CL-20 derivatives were studied by using density functional theory. It is found that the trinitromethyl group is an effective structural unit for improving the gas-phase HOFs and energetic properties of the derivatives. However, incorporating the dinitromethyl group into the parent compound is not favorable for increasing its HOFs and detonation properties. The effects of the dinitromethyl or trinitromethyl groups on the stability of the parent compound are discussed. The studies on strain energies show that the introduction of the trinitromethyl group intensifies the strain of the cage skeleton for the title compounds, whereas for the dinitromethyl groups, the case is quite the contrary. An analysis of the bond dissociation energies for several relatively weak bonds suggests that the substitution of the dinitromethyl or trinitromethyl group decreases the thermal stability of the derivatives. The C−NO2 bond in the dinitromethyl or trinitromethyl group is the weakest one and the homolysis of the C−NO2 bond may be the initial step in thermal decomposition. In addition, according to the calculated free space per molecule, the introduction of the dinitromethyl or trinitromethyl group increases the impact sensitivities of the derivatives. Considering the detonation performance, thermal stability, and impact sensitivity, six compounds can be regarded as the target high-energetic compounds.


2021 ◽  
Vol 03 (02) ◽  
pp. 141-145
Author(s):  
Jorge Labella ◽  
Elisa López-Serrano ◽  
Tomás Torres

The great potential of subphthalocyanines (SubPcs) to stabilize boron peroxides has been demonstrated. In particular, a subphthalocyanato boron (III) peroxide has been prepared in good yield via boron triflate. This derivative is remarkably stable under ambient conditions and can be fully characterized. The impact of the peroxide group on the structural and optoelectronic properties of SubPc was examined by NMR and UV/Vis spectroscopies, as well as single-crystal X-ray diffraction analysis. Moreover, density functional theory calculations were performed to explain the experimental results. The reactivity of this peculiar boron peroxide as an oxidant and a Lewis base was also studied.


2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Darnel J. Allen ◽  
Wayne E. Archibald ◽  
John A. Harper ◽  
John C. Saputo ◽  
Daniel Torres

We employ first-principles density functional theoretical calculations to address the inclusion of gold (Au) clusters in a well-packed CH3S self-assembled lattice. We compute CH3S adsorption energies to quantify the energetic stability of the self-assembly and gold adsorption and dissolution energies to characterize the structural stability of a series of Au clusters adsorbed at the SAM-Au interface. Our results indicate that the inclusion of Au clusters with less than four Au atoms in the SAM-Au interface enhances the binding of CH3S species. In contrast, larger Au clusters destabilize the self-assembly. We attribute this effect to the low-coordinated gold atoms in the cluster. For small clusters, these low-coordinated sites have significantly different electronic properties compared to larger islands, which makes the binding with the self-assembly energetically more favorable. Our results further indicate that Au clusters in the SAM-Au interface are thermodynamically unstable and they will tend to dissolve, producing Au adatoms incorporated in the self-assembly in the form of CH3S-Au-SCH3 species. This is due to the strong S-Au bond which stabilizes single Au adatoms in the self-assembly. Our results provide solid insight into the impact of adatom islands at the CH3S-Au interface.


2020 ◽  
Vol 27 (03) ◽  
Author(s):  
VO THANH CONG ◽  
QUY DIEM DO ◽  
PHAM THANH TAM ◽  
VAN THANH KHUE ◽  
PHAM VAN TAT

Calculations of adsorption and reaction mechanism on ZnO  surface have been investigated. In this work, the deposition of six atomic copper clusters (6Cu) on ZnO  surface (called 6Cu/ZnO  model), using density functional theory was employed to calculate for CO and H2O co-adsorption. In performance, on ZnO  surface, 6Cu were adsorbed to obtain four stable sites of 6Cu/ZnO model, called as 6Cu-I, 6Cu-II, 6Cu-III, and 6Cu-IV. The calculated results found that the 6Cu-IV was the most stable surface model, thus, used to examine the co-adsorption of CO and H2O molecules. Further, CO and H2O co-adsorption on ZnO  surface were calculated also to compare with 6Cu/ZnO surface. Based on co-adsorption energy calculations indicated that CO and H2O co-adsorption on 6Cu/ZnO surface were more favorable than on ZnO  surface. The studied results will provide an insight into the effective adsorption of cluster on ZnO-based surface by deposition.


2006 ◽  
Vol 979 ◽  
Author(s):  
Darko Simonovic ◽  
Marcel H. F. Sluiter

AbstractWe seek to explain 1) the effectiveness of substituting Sc with Dy, Er, Y and 2) the loss of properties when Sc is replaced with Yb, Gd and Sm [1]. For a preliminary insight into the stability of structures we utilize the concept of Atomic Environment Type (AET) as pertaining to trialuminides. Electronic density functional total energy calculations at zero temperature are performed to obtain the enthalpy of mixing of quasi-binary Al-Sc-X structures. Estimates of the entropy are used to compute the stability regions of Al3Sc1-αXα L12 phase. We show that Sc is completely miscible with X=Dy, Er, Y and that there is a miscibility gap for X=Yb, Gd and Sm at temperatures near the aging temperature of Al-Sc alloys.


2020 ◽  
Vol 8 (5) ◽  
pp. 2613-2617 ◽  
Author(s):  
Bingkai Zhang ◽  
Zhan Lin ◽  
Haibiao Chen ◽  
Lin-Wang Wang ◽  
Feng Pan

A molecular-level understanding of interfacial reactions and dynamics at the sLiF/LE interface in Li-metal battery systems inspire future work in sLiF coating layer for electrode and electrolyte applications.


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