XANES Spectroscopy Research Articles

Investigation of the oxidation process in GeTe-based phase change alloy using Ge K-edge XANES spectroscopy

Abstract In this work, we clearly demonstrate the efficacy of using XANES spectroscopy in conjunction with a Pilatus detector as a sensitive tool to allow the study of the oxidation process in GeTe alloys via depth profile analysis. On the basis of Ge K-edge XANES spectra, it was found that GeTe alloys do not oxidize readily after an initial native surface oxidation that occurs upon exposure to oxygen in the air at the elevated temperatures, 100 °C and 330 °C. We demonstrate that amorphous GeTe possesses a higher predisposition to oxidation than crystalline GeTe when exposed to the air at temperature of 100 °C. When the temperature is set to 330 °C in an air ambient, we show that the amorphous to crystal phase transition affects the oxidation process more significantly than the simple annealing of crystalline GeTe. We suggest that the higher tendency of GeTe films to oxidize during the phase transition is a consequence of the breaking of Ge–Ge bonds in the presence of oxygen atoms which subsequently leads to the extra formation of Ge–O bonds during crystallization.

The reduction of cis-platinum(iv) complexes by ascorbate and in whole human blood models using 1H NMR and XANES spectroscopy.

The efficacy of platinum(iv) prodrugs depends on their relative resistance to reduction in the extra- and intra-cellular environments. In the study reported here we investigated the influence of the nature of the axial and equatorial ligands on the pathway of reduction of the platinum(iv) complexes by the endogenous reductant, ascorbate, and their relative resistance to reduction in human blood serum and in a whole human blood model. The pathway of reduction of platinum(iv) complexes in the presence of excess ascorbate was found to be dependent on the nature of their axial and equatorial ligands in that complexes with chloride in the equatorial sites lost either both axial ligands or combinations of axial and equatorial ligands while those with oxalate occupying the equatorial sites lost both axial ligands only. Using XANES spectroscopy, complexes with axial hydroxide ligands were found to be highly resistant to reduction in blood serum and were only slowly and incompletely reduced in whole blood. The dihydroxide complex with an oxalate ligand occupying the equatorial leaving group sites was more resistant to reduction, both in serum and in whole blood, than the complex with chloride ligands in these sites. cis, trans-[PtCl2(OAc)2(en)] and trans-[Pt(OAc)2(ox)(en)] were observed to be reduced rapidly and almost completely in whole blood but the latter was substantially resistant to reduction in human blood serum, and consequently demonstrates many of the features of an optimal platinum(iv) anticancer agent.

Structure, dissolution, and plant uptake of ferrous/zinc phosphates

Development of slow release fertilizers by tuning dissolution kinetics can reduce the environmental impact of (micro) nutrients added to crops. Mixed metal compounds may have different dissolution kinetics and plant uptake than single metal compounds. In this study, mixed Fe(II)/Zn(II) phosphates (0–100 at% Zn) were prepared by aqueous precipitation and their structural characteristics and dissolution kinetics in a sand column were measured as model for divalent metal and phosphate release in soil. Three minerals were identified, namely vivianite (Fe3(PO4)2·8H2O) at 0–20 at% Zn, phosphophyllite (Zn2Fe(PO4)2·4H2O) at 20–79 at% Zn, and hopeite (Zn3(PO4)2·4H2O) at 79–100 at% Zn. The Fe-rich materials had high SSA of 42–64 m2 g−1, which decreased to ≤4 m2 g−1 for ≥79 at% Zn. The Fe K-edge and Zn K-edge XANES spectroscopy measurements show that the samples had comparable local structure and contained 13–72% of Fe as Fe(III) due to partial oxidation. In the sand column, Zn(II) and Fe(II) phosphates dissolved near-congruently at steady state (>7 h), whereas mixed Fe(II)/Zn(II) phosphates showed preferential release of Zn over P and Fe, likely due to reprecipitation of Fe. Pot experiments demonstrate that Zn from Fe(II)/Zn(II) phosphates is absorbed by bird's eye chili plants (C. annuum), in agreement with the preferential dissolution of Zn(II). These results may provide insight into the dissolution of other divalent metals, which not only aids in the growth of plants and resulting foodstuff but ultimately leads to reductions in environmental contamination.

Evidence for syngenetic micro-inclusions of As3+- and As5+-containing Cu sulfides in hydrothermal pyrite

Most frequently arsenic is nominally monovalent (As1–) in pyrite (FeS2) and substituted for S. Nominally trivalent arsenic (As3+) has been reported previously in hydrothermal Peruvian pyrite and was considered to be substituted for Fe based on the negative correlation between the concentrations of the two elements. Here, we provide the first observation of the incorporation of As3+ in goldfieldite [Cu12(As,Sb,Bi)2Te2S13] and As5+ in colusite [Cu26V2(As,Sb)4Sn2S32] inclusions in As1–-pyrite from high-sulfidation deposits in Peru. This information was obtained by combining spatially resolved electron probe (EPMA), synchrotron-based X‑ray fluorescence (SXRF), and absorption spectroscopy (micro-XANES and micro-EXAFS) with new high energy-resolution XANES spectroscopy (HR-XANES). The two Cu sulfide inclusions range from several to one hundred micrometers in size, and the As3+/As5+ concentration varies from a few parts per million (ppm) to a maximum of 17.33 wt% compared to a maximum of 50 ppm As1– in pyrite. They also contain variable amounts of Sn (18.47 wt% max), Te (15.91 wt% max), Sb (8.54 wt% max), Bi (5.53 wt% max), and V (3.25 wt% max). The occurrence of As3+/As5+-containing sulfosalts in As1–-containing pyrite grains indicates that oxidizing hydrothermal conditions prevailed during the late stage of the mineralization process in the ore deposits from Peru. From an environmental perspective, high concentrations of potentially toxic As, contained in what appear to be non-As-bearing pyrite, may pose a heretofore unrecognized threat to ecosystems in acid mine drainage settings. More generally, the combination of techniques used in this study offers a new perspective on the mineralogy and crystal chemistry of hazardous elements in pyrite, such as highly toxic and little studied thallium.

Iron-based nanoparticles prepared from yerba mate extract. Synthesis, characterization and use on chromium removal

Iron-based nanoparticles were synthesized by a rapid method at room temperature using yerba mate (YM) extracts with FeCl3 in different proportions. Materials prepared from green tea (GT) extracts were also synthesized for comparison. These materials were thoroughly characterized by chemical analyses, XRD, magnetization, SEM-EDS, TEM-SAED, FTIR, UV–Vis, Raman, Mössbauer and XANES spectroscopies, and BET area analysis. It was concluded that the products are nonmagnetic iron complexes of the components of the extracts. The applicability of the materials for Cr(VI) (300 μM) removal from aqueous solutions at pH 3 using two Cr(VI):Fe molar ratios (MR), 1:3 and 1:0.5, has been tested. At Cr(VI):Fe MR = 1:3, the best YM materials gave complete Cr(VI) removal after two minutes of contact, similar to that obtained with commercial nanoscale zerovalent iron (N25), with dissolved Fe(II), and with a likewise prepared GT material. At a lower Cr(VI):Fe MR (1:0.5), although Cr(VI) removal was not complete after 20 min of reaction, the YM nanoparticles were more efficient than N25, GT nanoparticles and Fe(II) in solution. The results suggest that an optimal Cr(VI):Fe MR ratio could be reached when using the new YM nanoparticles, able to achieve a complete Cr(VI) reduction, and leaving very low Cr and Fe concentrations in the treated solutions. The rapid preparation of the nanoparticles would allow their use in removal of pollutants in soils and groundwater by direct injection of the mixture of precursors.

Frontispiece: Mercury(II) Binding to Metallothionein in Mytilus edulis revealed by High Energy‐Resolution XANES Spectroscopy

Frontispiece: Mercury(II) Binding to Metallothionein in <i>Mytilus edulis</i> revealed by High Energy‐Resolution XANES Spectroscopy

Fluorescence Mode XANES Spectroscopy as a Powerful Tool for Redox-Isomerism Studies in Ultrathin Films

Fluorescence Mode XANES Spectroscopy as a Powerful Tool for Redox-Isomerism Studies in Ultrathin Films

Mercury(II) Binding to Metallothionein in Mytilus edulis revealed by High Energy-Resolution XANES Spectroscopy.

Of all divalent metals, mercury (HgII) has the highest affinity for metallothioneins. HgII is considered to be enclosed in the α and β domains as tetrahedral α‐type Hg4Cys11‐12 and β‐type Hg3Cys9 clusters similar to CdII and ZnII. However, neither the four‐fold coordination of Hg nor the existence of Hg–Hg atomic pairs have ever been demonstrated, and the HgII partitioning among the two protein domains is unknown. Using high energy‐resolution XANES spectroscopy, MP2 geometry optimization, and biochemical analysis, evidence for the coexistence of two‐coordinate Hg‐thiolate complex and four‐coordinate Hg‐thiolate cluster with a metacinnabar‐type (β‐HgS) structure in the α domain of separate metallothionein molecules from blue mussel under in vivo exposure is provided. The findings suggest that the CXXC claw setting of thiolate donors, which only exists in the α domain, acts as a nucleation center for the polynuclear complex and that the five CXC motifs from this domain serve as the cluster‐forming motifs. Oligomerization is driven by metallophilic Hg⋅⋅⋅Hg interactions. Our results provide clues as to why Hg has higher affinity for the α than the β domain. More generally, this work provides a foundation for understanding how metallothioneins mediate mercury detoxification in the cell under in vivo conditions.

The effect of melt composition and oxygen fugacity on manganese partitioning between apatite and silicate melt

Oxygen fugacity and melt composition are both known to have a strong influence on the partitioning of trace elements between coexisting minerals and melt. Previous work has suggested that Mn partitioning between apatite and silicate melt may be strongly affected by oxygen fugacity and could, therefore, act as an oxybarometer. Here, we present a new study on the partitioning of Mn between apatite and melt at high temperature (1400–1250 °C) and 1 GPa pressure, for various melt compositions and oxygen fugacities (NNO +4.7 to NNO -10). We find that there is no demonstrable variation in the partition coefficient for Mn between apatite and silicate melt (DMnAp-m) across the range of fO2 conditions studied here. Instead, we find that DMnAp-m varies significantly with melt composition and that in particular, the proportion of non-bridging oxygens strongly influences partitioning of Mn between apatite and melt. We propose that variations in the Mn content of natural apatite, previously thought to reflect variations in fO2, are instead related to the degree of melt polymerisation. These findings are consistent with the results of Mn K-edge XANES spectroscopy, which demonstrate that Mn in coexisting apatite and silicate glass is present predominantly as Mn2+ regardless of fO2. Furthermore, XANES spectra from a series of silicate glasses synthesised at various oxygen fugacities demonstrate that Mn2+ is the predominant species, and that the average Mn oxidation state does not vary over a wide range of fO2-T conditions.

Aeolian dust deposition and the perturbation of phosphorus transformations during long-term ecosystem development in a cool, semi-arid environment

Abstract Aeolian dust deposition is an important phosphorus (P) input to terrestrial ecosystems, but its influence on P dynamics during long-term ecosystem development remains poorly understood. In this study, we characterized P speciation using P K-edge XANES spectroscopy in surface soils (0–15 cm, A horizon) and contemporary aeolian dust collected at each site of a 3000-ky volcanic soil chronosequence in a cool, semi-arid environment. Phosphorus speciation in dust was dominated by calcium-bound P (Ca-P; 54–74%), with 11–23% iron and aluminum-bound P [(Fe + Al)-P] and 7–25% organic P (Po). In soils, Po contributed 1–23% of total P, being greater in older soils; however, the proportions of Ca-P (16–39%) and (Fe + Al)-P (48–82%) fluctuated with increasing weathering over the soil chronosequence. These soil fluctuations resulted from the accumulation and preservation of alkaline aeolian dust during pedogenesis in the semi-arid climate, which significantly increased soil Ca-P while decreasing the total amounts and relative abundances of soil (Fe + Al)-P. We suggest that the effects of an aeolian dust input on soil P transformations are functions of the relative magnitude and chemical composition of the dust input and the soil weathering intensity. For a given source of dust, when the net dust flux is greater than the weathering rate, dust accumulates and thus alters the pattern of P transformations during pedogenesis; otherwise, the dust influence on soil P transformations is negligible. By accurately identifying the chemical nature of P pools, our work highlights the advantage of P K-edge XANES spectroscopy over chemical extractions in examining soil P dynamics, and demonstrates how dust inputs can modify the Walker and Syers model of pedogenic P transformations in semi-arid environments. Overall, this work provides a foundation for understanding how dust influences P cycling during soil and ecosystem development, and indicates that dust inputs and composition, and the soil weathering rate, all must be considered for developing integrated climate-biogeochemical models with predictive power in terrestrial ecosystems.

Phosphorus characterization and plant availability in soil profiles after long-term urban waste application

Recycling of waste products to agricultural fields is important for sustainable crop production, particularly for managing phosphorus (P). How different forms of waste affect the accumulation, transformation and plant availability of P in soil is therefore of major interest. A long-term experimental field that assesses conventional fertilizers with that of urban wastes was analyzed for P accumulation, P speciation characterized using XANES and NMR spectroscopy, as well as plant P availability with DGT in top and sub horizons. Treatments included unfertilized, NPK, manure, sludge and compost amended soils. We found that long-term sludge application showed higher soil P availability in the soil relative to P input and total P content than in manure and compost amended soils. In the sludge amended soil, P was found to be more associated to Fe as opposed to Ca in the compost amended soil. In the manure amended soil, unfertilized and NPK soils P was mainly associated to organic P. Based on characterization of the waste products using XANES spectroscopy our results indicate that the P species in the sludge amended soil do not directly relate to the sludge material applied to the soil, but rather to the processes occurring in the soil after application. A larger association of P to Fe was also found in sub horizons of the sludge amended soil. We did not detect substantial differences in classes of organic P between the sludge and compost amended soils by the 31P NMR spectra. Our results indicate that sewage sludge is a useful fertilizer, as P applied with sludge remains highly plant available in these soils after long-term application, and it proves more plant available in the long-term than manure and compost fertilizers.

Xanes Specroscopic Diagnostics of the 3D Local Atomic Structure of Nanostructured Materials

A review of current works on XANES spectroscopy applied for the determination of parameters of a threedimensional local atomic structure of nanostructured materials is given. Special attention is paid to a new method based on the theoretical analysis of XANES spectra by means of multivariate interpolation. The uniqueness of the technique consists not only in the highly accurate (up to 0.01 A) determination of interatomic distances in materials without a long-range order in the atomic arrangement but also the estimation of the angular distribution of atoms (i.e. chemical bond angles) in any condensed materials. Several types of nanostructured materials, including coordination compounds, semiconductor quantum dots, nanosized structures in quasicrystals and extraterrestrial materials are given as examples.

Antimony mobility in reducing environments: The effect of microbial iron(III)-reduction and associated secondary mineralization

Antimony is an environmental contaminant, whose mobility in soils, sediments and groundwater systems is strongly influenced by interactions with Fe(III) oxide minerals. When exposed to reducing conditions, these minerals can undergo reductive dissolution via the activity of Fe(III)-reducing microorganisms, thereby potentially liberating previously retained Sb. In addition, microbial Fe(III)-reduction and the consequent production of Fe(II) can induce the formation of secondary Fe(III)- and Fe(II)-bearing minerals, which may alter the speciation and partitioning of Sb. In this study, we examined Sb behaviour during (1) the microbially-mediated reduction and transformation of Sb(V)-bearing ferrihydrite by the dissimilatory Fe(III)-reducing bacterium, Shewanella putrefaciens (strain CN32), and (2) during the associated abiotic Fe(II)-catalyzed transformation of Sb(V)-bearing ferrihydrite. Antimony K-edge XANES spectroscopy showed negligible reduction of Sb(V) to Sb(III) in both experiments, reflecting the redox stability of Sb(V) under these conditions. X-ray diffraction and Fe K-edge EXAFS spectroscopy revealed that both microbially-mediated Fe(II) production as well as the experimental addition of aqueous Fe(II) under abiotic conditions triggered rapid transformation of the initial ferrihydrite to feroxyhyte (δ′-FeOOH) and goethite (α-FeOOH). Goethite has been widely observed as a product of the Fe(II)-catalyzed transformation of ferrihydrite. However, the present study is the first to document the formation of feroxyhyte via this pathway, with feroxyhyte formation appearing to be favored by the presence of Sb(V). The formation of these secondary Fe(III) oxides was associated with substantial decreases in aqueous Sb concentrations and in the amount of surface-bound Sb (as defined via extractions with 1 M PO43−). This is consistent with the incorporation of Sb(V) into the newly formed feroxyhyte and goethite via substitution for Fe(III). The results of this study provide new perspectives on coupling between Sb geochemistry and Fe mineralogy by showing that microbial Fe(III)-reduction and associated secondary Fe(III)-oxide formation can help to immobilize Sb(V) in reducing environments.

Jouravskite: refined data on the crystal structure, chemical composition and spectroscopic properties

Refined data on the crystal structure, chemical composition and properties of jouravskite, ideally Ca3Mn4+(SO4)(CO3)(OH)6·12H2O, have been obtained on a sample from N’Chwaning 3 Mine, Kuruman, Kalahari manganese field, Northern Cape Province, South Africa. The chemical composition determined using a combination of different methods (including ICP-OES, gas chromatography of products of ignition and electron microprobe) is (wt%): CaO 25.88, SrO 0.19, BaO 0.23, B2O3 0.39, Fe2O3 1.01, MnO2 12.00, SiO2 0.06, CO2 6.8, SO3 12.44, H2O 41.8, total 100.80, which corresponds to the empirical formula (Z = 2): (Са2.98Sr0.01Ba0.01)Σ3.00(Mn4+0.89Fe3+0.08Si0.01)Σ0.98{(SO4)1.00(CO3)1.00[B(OH)4]0.07}Σ2.07(OH)5.78·11.94H2O. Tetravalent state of Mn was confirmed by Mn K-edge XANES spectroscopy. The IR spectrum of jouravskite contains characteristic bands of Mn4+(OH)6 octahedra, CO32− and SO42− anions, and H2O molecules. The crystal structure was determined using single-crystal X-ray diffraction data and refined to R = 0.0332. Jouravskite is isostructural with thaumasite. The parameters of the hexagonal (space group P63) unit cell are: a = 11.07129(14) A, c = 10.62650(14) A, V = 1128.02(3) A3 and Z = 3. Investigation of other samples of ettringite-group minerals from N’Chwaning 3 Mine demonstrates wide variations of the contents of manganese, iron and boron, and possible existence of a Mn4+-dominant analogue of sturmanite with the presumed idealized formula Са6Mn4+2(SO4)2[B(OH)4](OH)10O2·nH2O.

The oxidation state of iron in Mid-Ocean Ridge Basaltic (MORB) glasses: Implications for their petrogenesis and oxygen fugacities

The oxidation state of a basaltic liquid may be obtained from the average valence state of Fe in its quenched glass. Suitable glasses are widely available from the basalts erupted at Mid-Ocean Ridges (MORB). Measurements of Fe3+/∑Fe, where ∑Fe=Fe2++Fe3+, by XANES spectroscopy of a globally representative sample of these MORB glasses are in good agreement with the most recent literature values determined by wet chemistry, but have improved precision, with an expected standard deviation of ±0.01 in Fe3+/∑Fe for each independent measurement. These precise data allow the geochemical controls on MORB redox systematics at both global and local scales to be evaluated. At the global scale, the relationship between log[Fe2O3] and [MgO] shows that Fe3+ behaves like a lightly incompatible element (LICE) during the crustal evolution of MORB, with its incompatibility between those of the redox-insensitive elements Li and In. The variability of Fe3+ about this global trend is also consistent with that of redox-insensitive elements of similar incompatibility, implying no external buffering of oxygen fugacity (fO2). The variability of Fe3+ is anti-correlated with the variabilities of Sr and Na, which are compatible in plagioclase, but is positively correlated with the variabilities of elements that partition preferentially into clinopyroxene and/or olivine rather than plagioclase, showing that its variability is controlled at least partly by varying ratios of plagioclase to clinopyroxene and olivine during the crustal evolution of MORB. Deviations of Fe3+ concentrations from the global trend are, like those of other LICE, anticorrelated with the deviations from their global trends of the very incompatible elements (VICE). Extrapolation of the global trend to an assumed parental melt at 10.4 wt% [MgO] gives [Fe2O3]o, the concentration of Fe2O3 in the global average MORB parental melt, of 0.6 wt%, which is consistent with 15–20% partial melting of a spinel lherzolite source with 0.2 to 0.3 wt% Fe2O3. This estimate of source Fe2O3 agrees with the estimate for fertile upper mantle lherzolite deduced from measurements of Fe3+/∑Fe and total Fe in the minerals of spinel peridotite xenoliths from the lithosphere.The fO2 of the MORB glasses at 1 bar may be calculated from their measured Fe3+/∑Fe using a new parameterization of 478 experimental data from the literature with <60 wt% SiO2. The need for the new parameterization arises from recent experimental studies, which, among other aspects, are consistent with the ideal stoichiometry governing the thermodynamic relationship between Fe3+/Fe2+ and fO2, namely Fe3+/Fe2+ ∝ (fO2)0.25. The parameterization gives:log10⁡(Fe3+/Fe2+)=0.25ΔQFM−1.35+0.034[Na2O]+0.044[K2O]+0.023[CaO]−0.18[P2O5] where ΔQFM is the difference between the fO2 of the silicate melt and the quartz–fayalite–magnetite buffer in log10 units, logfO2(QFM) =8.58−25050/T, relative to the conventional standard state of pure O2 at 105 Pa, T is in K, and [Na2O] etc., are the concentrations of the oxide components in weight percent. The global average ΔQFM recorded by MORB glasses in the compositional range of 5 to 10 wt% MgO is +0.2 ±0.3, with a small but resolvable increase with decreasing MgO. There is no evidence that Fe3+/∑Fe systematics in MORB are influenced by interactions with other polyvalent elements like S or Cr.

Do Olefin Hydrogenation Reactions Remain Structure Insensitive over Pt in Nanostructured Pt-on-Au Catalyst?

Understanding the effects of catalyst surface structure on a catalytic reaction is of fundamental importance in catalysis chemistry. Herein, a series of Pt-on-Au (Ptm^Au, m refers to the atomic Pt/Au ratio; Au size: 3.2 ± 0.4 nm) nanostructures with Pt dispersion in the range of 38% to 100% are used to study the structure sensitivity of the hydrogenation reactions of 1,3-butadiene and ethylene, respectively. The specific catalytic rates for both reactions are observed to increase with a decrease in the Pt dispersion or increasing m in Ptm^Au, demonstrating the structure-sensitive nature of both reactions over the Ptm^Au nanostructures. These observations strongly contrast with the structure insensitivity of the same reactions over our deliberately prepared counterpart Pt/SiO2 catalysts with Pt dispersion varying in 6%∼100% and also those documented in literature and thus identify a distinct feature of Pt in the Ptm^Au nanostructures. Characterization results from XANES spectroscopy and DRIFTS of adsorbed ...

Critical evaluation of zinc speciation in geochemical reference materials by combining sequential extraction and XANES spectroscopy

Critical evaluation of zinc speciation in geochemical reference materials by combining sequential extraction and XANES spectroscopy

Assessing the ability of soil tests to estimate labile phosphorus in agricultural soils: Evidence from isotopic exchange

Efficient phosphorus (P) fertilization strategies are essential for intensive crop production with minimal negative environmental impacts. A key factor in sustainable P use is assessment of the plant available soil P pool using soil P tests. This study determined isotopically exchangeable P after six days of reaction with 33PO4 (P-E (6 d)) to determine how accurately two commonly used P tests, Olsen and AL (acid ammonium acetate lactate) can quantify the amount of labile P. Soil samples were taken from both highly P-amended and unamended plots at six sites within the Swedish long-term soil fertility experiments. According to P K-edge XANES spectroscopy, the P speciation was dominated by Al-bound P and organic P, with additional contributions from Fe-bound P and Ca phosphates in most soils. The results showed that the AL test overestimated P-E (6 d) by a factor of 1.70 on average. In contrast, the Olsen test underestimated P-E (6 d), with the mean ratios of P-Olsen to P-E (6 d) being 0.52 for high-P and 0.19 for low-P soils. The 33P/31P ratio in the Olsen extract of a 33PO4 spiked soil was closer to that of a 0.005 mol L−1 CaCl2 soil extract than the corresponding ratio in the AL extract, suggesting that AL extraction solubilized more non-labile P. In conclusion, the AL and Olsen methods are not suitable for direct quantification of the isotopically exchangeable soil P pool after 6 days of equilibration. However, based on the results, Olsen may be superior to AL for classification of soil P status, due to its even performance for calcareous and non-calcareous soils and lower extraction of non-labile P.

Antimony-Functionalized Phosphine-Based Photopolymer Networks.

The synthesis of phosphane-ene photopolymer networks, where the networks are composed of crosslinked tertiary alkyl phosphines are reported. Taking advantage of the rich coordination chemistry of alkyl phosphines, stibino-phosphonium and stibino-bis(phosphonium) functionalized polymer networks could be generated. Small-molecule stibino-phosphonium and stibino-bis(phosphonium) compounds have been well characterized previously and were used as models for spectroscopic comparison to the macromolecular analogues by NMR and XANES spectroscopy. This work reveals that the physical and electronic properties of the materials can be tuned depending on the type of coordination environment. These materials can be used as ceramic precursors, where the Sb-functionalized polymers influence the composition of the resulting ceramic.

Antimony‐Functionalized Phosphine‐Based Photopolymer Networks

AbstractThe synthesis of phosphane‐ene photopolymer networks, where the networks are composed of crosslinked tertiary alkyl phosphines are reported. Taking advantage of the rich coordination chemistry of alkyl phosphines, stibino‐phosphonium and stibino‐bis(phosphonium) functionalized polymer networks could be generated. Small‐molecule stibino‐phosphonium and stibino‐bis(phosphonium) compounds have been well characterized previously and were used as models for spectroscopic comparison to the macromolecular analogues by NMR and XANES spectroscopy. This work reveals that the physical and electronic properties of the materials can be tuned depending on the type of coordination environment. These materials can be used as ceramic precursors, where the Sb‐functionalized polymers influence the composition of the resulting ceramic.