Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 125
Filter
Add more filters










Publication year range
1.
Bioethics ; 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38887844

ABSTRACT

This article objects to two arguments that William MacAskill gives in What We Owe the Future in support of optimism about the prospects of longtermism, that is, the prospects of positively influencing the longterm future. First, it grants that he is right that, whereas humans sometimes benefit others as an end, they rarely harm them as an end, but argues that this bias towards positive motivation is counteracted by the fact that it is practically easier to harm than to benefit. For this greater easiness makes it likely both that accidental effects will be harmful rather than beneficial and that the means or side-effects of the actions people perform with the aim of benefiting themselves and those close to them will tend to be harmful to others. Secondly, while our article agrees with him that values could lock-in, it contends that the value of longtermism is unlikely to lock in as long as human beings have not been morally enhanced but remain partial in favor of themselves and those near and dear.

2.
Dalton Trans ; 53(4): 1817-1832, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38173416

ABSTRACT

Crystallographic investigations of eight homoleptic N,N'-dimethylpropyleneurea (dmpu) coordinated metal ions in the solid state, [Mg(dmpu)5]I2 (1), [Ca(dmpu)6]I2 (2), [Ca(dmpu)6](ClO4)2 (3), [Ca(dmpu)6](CF3SO3)2 (4), [Sr(dmpu)6](CF3SO3)2 (5), [Ba(dmpu)6](CF3SO3)2 (6), [Sc(dmpu)6]I3 (7), and [Pr(dmpu)6]I(I3)2 (8), and the complex [CoBr2(dmpu)2] (9) as well as the structures of the dmpu coordinated calcium, strontium, barium, scandium(III) and cobalt(II) ions and the cobalt(II) bromide complex in dmpu solution as determined by EXAFS are reported. The methyl groups in the dmpu molecule are close to the oxygen donor atom, causing steric restrictions, and making dmpu space-demanding at coordination to metal ions. The large volume required by the dmpu ligand at coordination contributes to crowdedness around the metal ion with often lower coordination numbers than for oxygen donor ligands without such steric restrictions. The crowdedness is seen in M⋯H distances equal to or close to the sum of the van der Waals radii. To counteract the space-demand at coordination, the dmpu molecule has an unusual ability to increase the M-O-C bond angle to facilitate as large coordination numbers as possible. M-O-C bond angles in the range of 125-170° are reported depending on the crowdedness caused by the coordination figure and the M-O bond distance. All reported structures of dmpu coordinated metal ions in both the solid state and dmpu solution are summarized to study the relationship between the M-O-C bond angle and the crowdedness around the metal ion. However, highly symmetric complexes seem to be favoured in the solid state due to favourable lattice energies. As a result, the dmpu coordinated lanthanoid(III) ions are octahedral in the solid state, while they, except lutetium, are seven-coordinate in the dmpu solution.

3.
Inorg Chem ; 62(30): 12038-12049, 2023 Jul 31.
Article in English | MEDLINE | ID: mdl-37477287

ABSTRACT

Radium-226 carbonate was synthesized from radium-barium sulfate (226Ra0.76Ba0.24SO4) at room temperature and characterized by X-ray powder diffraction (XRPD) and extended X-ray absorption fine structure (EXAFS) techniques. XRPD revealed that fractional crystallization occurred and that two phases were formed─the major Ra-rich phase, Ra(Ba)CO3, and a minor Ba-rich phase, Ba(Ra)CO3, crystallizing in the orthorhombic space group Pnma (no. 62) that is isostructural with witherite (BaCO3) but with slightly larger unit cell dimensions. Direct-space ab initio modeling shows that the carbonate oxygens in the major Ra(Ba)CO3 phase are highly disordered. The solubility of the synthesized major Ra(Ba)CO3 phase was studied from under- and oversaturation at 25.1 °C as a function of ionic strength using NaCl as the supporting electrolyte. It was found that the decimal logarithm of the solubility product of Ra(Ba)CO3 at zero ionic strength (log10 Ksp0) is -7.5(1) (2σ) (s = 0.05 g·L-1). This is significantly higher than the log10 Ksp0 of witherite of -8.56 (s = 0.01 g·L-1), supporting the disordered nature of the major Ra(Ba)CO3 phase. The limited co-precipitation of Ra2+ within witherite, the significantly higher solubility of pure RaCO3 compared to witherite, and thermodynamic modeling show that the results obtained in this work for the major Ra(Ba)CO3 phase are also applicable to pure RaCO3. The refinement of the EXAFS data reveals that radium is coordinated by nine oxygens in a broad bond distance distribution with a mean Ra-O bond distance of 2.885(3) Å (1σ). The Ra-O bond distance gives an ionic radius of Ra2+ in a 9-fold coordination of 1.545(6) Å (1σ).

4.
Inorg Chem ; 62(28): 11188-11198, 2023 Jul 17.
Article in English | MEDLINE | ID: mdl-37385975

ABSTRACT

Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy is a technique routinely employed in the qualitative and quantitative analysis of phosphorus speciation in many scientific fields. The data analysis is, however, often performed in a qualitative manner, relying on linear combination fitting protocols or simple comparisons between the experimental data and the spectra of standards, and little quantitative structural and electronic information is thus retrieved. Herein, we report a thorough theoretical investigation of P K-edge XANES spectra of NaH2PO4·H2O, AlPO4, α-Ti(HPO4)2·H2O, and FePO4·2H2O showing excellent agreement with the experimental data. We find that different coordination shells of phosphorus, up to a distance of 5-6 Å from the photoabsorber, contribute to distinct features in the XANES spectra. This high structural sensitivity enables P K-edge XANES spectroscopy to even distinguish between nearly isostructural crystal phases of the same compound. Additionally, we provide a rationalization of the pre-edge transitions observed in the spectra of α-Ti(HPO4)2·H2O and FePO4·2H2O through density of states calculations. These pre-edge transitions are found to be enabled by the covalent mixing of phosphorus s and p orbitals and titanium or iron d orbitals, which happens even though neither metal ion is directly bound to phosphorus in the two systems.

5.
Neuroethics ; 15(2): 23, 2022.
Article in English | MEDLINE | ID: mdl-35784396

ABSTRACT

This paper clarifies and defends against criticism our argument in Unfit for the Future that there is no moral right to privacy. A right to privacy is conceived as a right that others do not acquire information about us that we reserve for ourselves and selected others. Information acquisition itself is distinguished from the means used to acquire it and the uses to which the information is put. To acquire information is not an action; it is to be caused to be in an internal state. By contrast, means of acquisition and uses of information are actions that can be voluntarily controlled. We can therefore have rights against others that they stay away from certain means and uses but not from information acquisition in itself. An omniscient, omnipotent and omnibeneficient being is not thought to violate a right to privacy because its means and uses of information are morally acceptable.

6.
Molecules ; 27(14)2022 Jul 06.
Article in English | MEDLINE | ID: mdl-35889216

ABSTRACT

The arrangement of bisphenol A molecules into organoclays and their interactions with the intercalated surfactant were studied. The organoclays were prepared via solid-state intercalation of four cationic surfactants, such as dodecyltrimethyl-, tetradecyltrimethyl-, hexadecyltrimethyl-, and didodecyldimethyl-ammonium, as bromide salts, at different loading levels into the interlayers of two natural clays. The natural clays, the prepared organoclays, and the spent organoclays were characterized by X-ray powder diffraction, infrared spectroscopy, and scanning electron microscopy. X-ray powder diffraction measurements showed successive interlayer expansions of the d001 basal spacing due to the intercalation of the cationic surfactants and the bisphenol A sorption. The increased d001 basal spacing of the organoclays after bisphenol A sorption indicates that the molecules are integrated between the alkyl chains of the surfactant in the organoclays interlayers. Infrared spectroscopy was employed to probe the intercalation of the cationic surfactants and the sorbed bisphenol A. New characteristic bands attributed to the bisphenol A phenol rings appear in the range 1518-1613 cm-1 on the infrared spectra of the spent organoclays, proving the presence of bisphenol A in the hydrophobic interlayers. Scanning electron microscopy of the organoclays before and after BPA sorption shows that their morphology becomes fluffy and that the presence of the organic molecules expands the clay structure.


Subject(s)
Aluminum Silicates , Phenols , Adsorption , Aluminum Silicates/chemistry , Benzhydryl Compounds , Clay , Surface-Active Agents/chemistry
7.
Dalton Trans ; 51(21): 8192-8207, 2022 May 31.
Article in English | MEDLINE | ID: mdl-35583237

ABSTRACT

Solid titanium phosphate, TiP, materials hold great promise for wastewater treatment for removal of metal ions and complexes. A series of TiP materials, synthesised at mild conditions and short reaction times, have been structurally characterised using solid-state X-ray absorption spectroscopy, phosphorus and titanium K edge XANES and EXAFS, and 31P and 47/49Ti NMR spectroscopy. The titanium K edge EXAFS data of α-Ti(HPO4)2·H2O (α-TiP) revealed octahedral coordination of oxygens around titanium. Repeated washing of primary ß-/γ-TiP with hydrochloric acid results in formation of a weakly ordered solid, TiO(OH)(H2PO4)·H2O, TiP1-H. The structure of TiP1-H is shown by Ti EXAFS to be a titanyl compound, containing a short TiO bond. The analogous data for linked titanium phosphate compounds (LTP) disclosed that inter-linkage occurs between α-TiP and titanyl phosphate units, supported by 31P-31P NOESY NMR data. 47/49Ti NMR and Ti pre-edge XANES show evidence of two different titanium environments in LTP, one very similar to that observed in TiP1-H and a second more symmetric octahedral environment. Data are discussed in terms of induced acidic hydrolyses of titanium(IV) and phosphate counterpart during washings with hydrochloric acid and water. A straightforward relation between synthesis parameters/post synthetic treatment and structural re-arrangement in the materials is established.

8.
Environ Sci Technol ; 56(5): 3076-3084, 2022 03 01.
Article in English | MEDLINE | ID: mdl-35129969

ABSTRACT

The use of bismuth in the society has steadily increased during the last decades, both as a substitute for lead in hunting ammunition and various metallurgical applications, as well as in a range of consumer products. At the same time, the environmental behavior of bismuth is largely unknown. Here, the binding of bismuth(III) to organic soil material was investigated using extended X-ray absorption spectroscopy (EXAFS) and batch experiments. Moreover, the capacity of suwannee river fulvic acid (SRFA) to enhance the solubility of metallic bismuth was studied in a long-term (2 years) equilibration experiment. Bismuth(III) formed exceptionally strong complexes with the organic soil material, where >99% of the added bismuth(III) was bound by the solid phase, even at pH 1.2. EXAFS data suggest that bismuth(III) was bound to soil organic matter as a dimeric Bi3+ complex where one carboxylate bridges two Bi3+ ions, resulting in a unique structural stability. The strong binding to natural organic matter was verified for SRFA, dissolving 16.5 mmol Bi per gram carbon, which largely exceeds the carboxylic acid group density of this compound. Our study shows that bismuth(III) will most likely be associated with natural organic matter in soils, sediments, and waters.


Subject(s)
Bismuth , Soil , Bismuth/chemistry , Rivers/chemistry , Solubility , X-Ray Absorption Spectroscopy
9.
Bioethics ; 36(4): 374-380, 2022 05.
Article in English | MEDLINE | ID: mdl-35080778

ABSTRACT

The deliverances of our conscience are heartfelt, but not necessarily reason-based, moral convictions that concern our own behaviour. The fact that conscientious objections to a regulation, like a prohibition or obligation, express a heartfelt conviction that it is morally wrong to comply or morally permissible not to comply with the regulation provides a moral reason to respect the conviction because failing to do so is likely to cause objectors considerable suffering. But for conscientious objections to succeed in justifying exempting objectors from complying with the regulation, the suffering caused by forcing compliance must outweigh the suffering produced by exempting them from compliance. In the case of obligations, this necessitates that others with a similar competence are available to replace them. Conscientious objectors can never justifiably demand to be granted exemptions. This takes acts of generosity made feasible by favourable circumstances, such as the availability of replacements.


Subject(s)
Conscience , Morals , Humans , Refusal to Treat
10.
ACS Catal ; 11(5): 2999-3008, 2021 Mar 05.
Article in English | MEDLINE | ID: mdl-33842022

ABSTRACT

A well-studied heterogeneous palladium(II) catalyst used for the cycloisomerization of acetylenic acids is known to be susceptible to deactivation through reduction. To gain a deeper understanding of this deactivation process and to enable the design of a reactivation strategy, in situ X-ray absorption spectroscopy (XAS) was used. With this technique, changes in the palladium oxidation state and coordination environment could be studied in close detail, which provided experimental evidence that the deactivation was primarily caused by triethylamine-promoted reduction of palladium(II) to metallic palladium nanoparticles. Furthermore, it was observed that the choice of the acetylenic acid substrate influenced the distribution between palladium(II) and palladium(0) species in the heterogeneous catalyst after the reaction. From the mechanistic insight gained through XAS, an improved catalytic protocol was developed that did not suffer from deactivation and allowed for more efficient recycling of the catalyst.

11.
Inorg Chem ; 59(23): 17291-17302, 2020 Dec 07.
Article in English | MEDLINE | ID: mdl-33233885

ABSTRACT

X-ray absorption spectroscopy (XAS) has been employed to study the coordination of the Ag+ ion in aqueous solution. The conjunction of extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) data analysis provided results suggesting the preference for a first shell linear coordination with a mean Ag-O bond distance of 2.34(2) Å, different from the first generally accepted tetrahedral model with a longer mean Ag-O bond distance. Ab initio molecular dynamics simulations with the Car-Parrinello approach (CPMD) were also performed and were able to describe the coordination of the hydrated Ag+ ion in aqueous solution in very good agreement with the experimental data. The high sensitivity for the closest environment of the photoabsorber of the EXAFS and XANES techniques, together with the long-range information provided by CPMD and large-angle X-ray scattering (LAXS), allowed us to reconstruct the three-dimensional model of the coordination geometry around the Ag+ ion in aqueous solution. The obtained results from experiments and theoretical simulations provided a complex picture with a certain amount of water molecules with high configurational disorder at distances comprised between the first and second hydration spheres. This evidence may have caused the proliferation of the coordination numbers that have been proposed so far for Ag+ in water. Altogether these data show how the description of the hydration of the Ag+ ion in aqueous solution can be complex, differently from other metal species where hydration structures can be described by clusters with well-defined geometries. This diffuse hydration shell causes the Ag-O bond distance in the linear [Ag(H2O)2]+ ion to be ca. 0.2 Å longer than in isolated ions in solid state.

12.
Inorg Chem ; 59(14): 9538-9550, 2020 Jul 20.
Article in English | MEDLINE | ID: mdl-32614569

ABSTRACT

The structures of the solvated copper(II) ion in water and nine organic oxygen donor solvents with similar electron-pair donor ability, but with different space-demanding properties at coordination, have been studied by EXAFS. N,N'-Dimethylpropyleneurea and N,N,N',N'-tetramethylurea are sufficiently space demanding at coordination to make the axial positions not accessible, resulting in square-planar copper(II) solvate complexes with an intense green color. The mean Cu-O bond distances in these two solvate complexes are 1.939(3) and 1.935(3) Å, respectively. The best fits of the remaining solvates, which are light blue in different hues, are obtained with a Jahn-Teller distorted-octahedral model consisting of four strongly bound solvent molecules in the equatorial positions at 1.96(2) Å and two in the axial positions but with different Cu-Oax bond distances: ca. 2.15 and 2.32 Å. This is in agreement with observations in solid-state structures of compounds containing hexaaquacopper(II) complexes crystallizing in noncentrosymmetric space groups and all reported crystal structures containing a [Cu(H2O)5(O-ligand)] complex with Jahn-Teller distortion. Such a structure is in agreement with previous EPR and EXAFS studies proving the hydrated copper(II) ion to be a noncentrosymmetric complex in aqueous solution. The refinements of the EXAFS data of the solids [Cu(H2O)6](ClO4)2, [Cu(H2O)6](BrO3)2, [Cu(H2O)6]SiF6, Cu(NO3)2·2.5H2O, and CuSO4·5H2O gave Cu-O bond distances significantly different from those reported in the crystallographic studies but similar to the configuration and bond distances in the hydrated copper(II) ion in aqueous solution. This may depend on whether the orientation of the axial positions is random in one or three dimensions, giving a mean structure of the solid with symmetry higher than that of the individual complexes. This study presents the very first experimental data from the new X-ray absorption spectroscopy beamline Balder at the MAX IV synchrotron radiation facility in Lund, Sweden, as well as the utilized properties of the beamline.

13.
Bioethics ; 34(6): 620-632, 2020 07.
Article in English | MEDLINE | ID: mdl-32433782

ABSTRACT

There are no egalitarians in a pandemic. The scale of the challenge for health systems and public policy means that there is an ineluctable need to prioritize the needs of the many. It is impossible to treat all citizens equally, and a failure to carefully consider the consequences of actions could lead to massive preventable loss of life. In a pandemic there is a strong ethical need to consider how to do most good overall. Utilitarianism is an influential moral theory that states that the right action is the action that is expected to produce the greatest good. It offers clear operationalizable principles. In this paper we provide a summary of how utilitarianism could inform two challenging questions that have been important in the early phase of the pandemic: (a) Triage: which patients should receive access to a ventilator if there is overwhelming demand outstripping supply? (b) Lockdown: how should countries decide when to implement stringent social restrictions, balancing preventing deaths from COVID-19 with causing deaths and reductions in well-being from other causes? Our aim is not to argue that utilitarianism is the only relevant ethical theory, or in favour of a purely utilitarian approach. However, clearly considering which options will do the most good overall will help societies identify and consider the necessary cost of other values. Societies may choose either to embrace or not to embrace the utilitarian course, but with a clear understanding of the values involved and the price they are willing to pay.


Subject(s)
Coronavirus Infections/epidemiology , Ethical Theory , Pandemics/ethics , Patient Rights/ethics , Pneumonia, Viral/epidemiology , COVID-19 , Emergency Medical Services/ethics , Humans , Social Justice/ethics
14.
Inorg Chem ; 59(12): 8231-8239, 2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32462867

ABSTRACT

The strength of hydrogen bonding to and structure of hydrated oxometallate ions in aqueous solution have been studied by double difference infrared (DDIR) spectroscopy and large-angle X-ray scattering (LAXS), respectively. Anions are hydrated by accepting hydrogen bonds from the hydrating water molecules. The oxygen atom of the permanganate and perrhenate ions form weaker and longer hydrogen bonds to water than the hydrogen bonds in bulk water (i.e., they act as structure breakers), while the oxygen atoms of the chromate, dichromate, molybdate, tungstate, and hydrogenvanadate ions form hydrogen bonds stronger than those in bulk water (i.e., they act as structure makers). The oxometallate ions form one hydration shell distinguishable from bulk water as determined by DDIR spectroscopy and LAXS. The hydration of oxoanions results in X-O bond distances ca. 0.02 Å longer than those in unsolvated ions in the solid state not involved in strong bonding to counterions. The oxygens of oxoanions with a central atom from the second and third series in the periodic table and the hydrogenvanadate ion hydrogen bind three hydrating water molecules, while oxygens of oxoanions with a heavier central atom only form hydrogen bonds to two water molecules.

15.
Chemistry ; 26(15): 3411-3419, 2020 Mar 12.
Article in English | MEDLINE | ID: mdl-31976570

ABSTRACT

The activation process of a known Ru-catalyst, dicarbonyl(pentaphenylcyclopentadienyl)ruthenium chloride, has been studied in detail using time resolved in situ X-ray absorption spectroscopy. The data provide bond lengths of the species involved in the process as well as information about bond formation and bond breaking. On addition of potassium tert-butoxide, the catalyst is activated and an alkoxide complex is formed. The catalyst activation proceeds via a key acyl intermediate, which gives rise to a complete structural change in the coordination environment around the Ru atom. The rate of activation for the different catalysts was found to be highly dependent on the electronic properties of the cyclopentadienyl ligand. During catalytic racemization of 1-phenylethanol a fast-dynamic equilibrium was observed.

16.
Nanomaterials (Basel) ; 10(1)2019 Dec 19.
Article in English | MEDLINE | ID: mdl-31861727

ABSTRACT

Amorphous calcium phosphate (ACP) has shown significant effects on the biomineralization and promising applications in bio-medicine. However, the limited stability and porosity of ACP material restrict its practical applications. A storage stable highly porous ACP with Brunauer-Emmett-Teller surface area of over 400 m2/g was synthesized by introducing phosphoric acid to a methanol suspension containing amorphous calcium carbonate nanoparticles. Electron microscopy revealed that the porous ACP was constructed with aggregated ACP nanoparticles with dimensions of several nanometers. Large angle X-ray scattering revealed a short-range atomic order of <20 Å in the ACP nanoparticles. The synthesized ACP demonstrated long-term stability and did not crystallize even after storage for over 14 months in air. The stability of the ACP in water and an α-MEM cell culture medium were also examined. The stability of ACP could be tuned by adjusting its chemical composition. The ACP synthesized in this work was cytocompatible and acted as drug carriers for the bisphosphonate drug alendronate (AL) in vitro. AL-loaded ACP released ~25% of the loaded AL in the first 22 days. These properties make ACP a promising candidate material for potential application in biomedical fields such as drug delivery and bone healing.

17.
Topoi (Dordr) ; 38(1): 7-14, 2019 Mar.
Article in English | MEDLINE | ID: mdl-31798198

ABSTRACT

We have a duty to try to develop and apply safe and cost-effective means to increase the probability that we shall do what we morally ought to do. It is here argued that this includes biomedical means of moral enhancement, that is, pharmaceutical, neurological or genetic means of strengthening the central moral drives of altruism and a sense of justice. Such a strengthening of moral motivation is likely to be necessary today because common-sense morality having its evolutionary origin in small-scale societies with primitive technology will become much more demanding if it is revised to serve the needs of contemporary globalized societies with an advanced technology capable of affecting conditions of life world-wide for centuries to come.

18.
J Ethics ; 23(2): 223-238, 2019.
Article in English | MEDLINE | ID: mdl-31327930

ABSTRACT

We present an analysis of a notion of the meaning of life, according to which our lives have meaning if we spend them intentionally producing what has value for ourselves or others. In this sense our lives can have meaning even if a science-inspired view of the world is correct, and they are only transient phenomena in a vast universe. Our lives are more or less meaningful in this sense due to the difference in value for ourselves and others we intentionally create while leading them. These inequalities are morally unjustifiable because they are ultimately due to factors beyond our responsibility and control. But from the point of view of eternity these differences in meaningfulness and value dwindle to insignificance, and this offers some consolation for the unjustifiable inequalities.

19.
J Chromatogr A ; 1605: 360329, 2019 Nov 08.
Article in English | MEDLINE | ID: mdl-31331655

ABSTRACT

This paper illustrates the development of a procedure based on the use of a low transition temperature mixture (LTTM) for the dispersive liquid-liquid microextraction (DLLME) of fungicides, insecticides and acaricides from surface waters. The LTTM preparation involves the heat-mixing of choline chloride and acetylsalicylic acid in a molar ratio 1:2 (ChCl(ASA)2). The resulting mixture appears as a clear viscous liquid at room-temperature, denser than water (1.20 ±â€¯0.01 g mL-1). For its characterization, differential scanning calorimetry (DSC) provided crucial evidence to classify it as a LTTM rather than as a deep eutectic solvent (DES) since it revealed an intense glass transition at -37 °C. Large-angle X-ray scattering (LAXS) confirmed the lack of any long-distance order. Due to the LTTM immiscibility with water, an evaluation study was carried out to test ChCl(ASA)2 as an effective alternative to the conventional chlorinated solvents for DLLME. To this end, 24 pesticides were used as model compounds, extracted from surface water samples (5 mL) and analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The definitive procedure required the optimization of some key parameters such as volume of extracting solvent, type and volume of dispersing solvent, volume of the aqueous sample, LTTM dispersion procedure, and extraction time. Depending on pKa and logP values, recoveries ranged from 18 (for very polar compounds) to 96%, revealing that the ideal candidates for the extraction with ChCl(ASA)2 are neutral compounds with logP >2. After complete validation, the method was applied to analyze water samples from the River Tiber where dodine and dimetomorph were found at low µg L-1 concentration levels.


Subject(s)
Environmental Monitoring/methods , Liquid Phase Microextraction , Pesticides/isolation & purification , Transition Temperature , Water Pollutants, Chemical/isolation & purification , Water/chemistry , Chromatography, High Pressure Liquid , Juvenile Hormones , Pesticides/analysis , Solvents/chemistry , Tandem Mass Spectrometry , Water Pollutants, Chemical/analysis
20.
Dalton Trans ; 48(25): 9089-9093, 2019 Jun 25.
Article in English | MEDLINE | ID: mdl-31062807

ABSTRACT

A very slow oxidation of dimethylsulfoxide (dmso) solvated tin(ii) ions in solution results in the formation of a crystalline, structurally determined compound, [CH3Sn(OS(CH3)2)5](ClO4)3, whereas a similar reaction in N,N-dimethylthioformamide (dmtf) forms a crystalline solid with a proposed binuclear [Sn2(SH)2(SCHN(CH3)2)8]6+ entity but whose exact formula remains undetermined. Both solids precipitate with time in their respective mother liquids and constitute the first two tin(iv) and even tetravalent d10 metal ion solvate complexes ever reported. An EXAFS study showed that the structure of the [CH3Sn(OS(CH3)2)5]3+ complex is identical in solid state and dmso solution. While the exact chemical reaction pathways are unknown, the formation of these complexes constitute a novel way of obtaining solvated tin(iv) ions in standard, commonplace organic media.

SELECTION OF CITATIONS
SEARCH DETAIL
...