Tin Atom Research Articles

The Lithium Iodostannate LiSn3I7: Synthesis, Properties and its Relationship to SnI2

AbstractThe mixed lithium tin iodide LiSn3I7 was prepared by reacting LiI and SnI2 at 300 °C. Single‐crystal X‐ray diffraction revealed a crystal structure related to that of SnI2, with nearly identical coordination environments of tin atoms. The lithium ion in the structure of LiSn3I7 shares one crystallographic position with a tin atom in octahedral voids of (LiSn)Sn2I7, as confirmed by solid‐state 7Li, 119Sn and 127I MAS NMR spectra. DFT band structure calculations show LiSn3I7 to be a semiconductor with an indirect bandgap on the order of 2 eV.

Study of doping two tin atoms per unit cell of silicene nanoribbons in the presence of an external electric field

Silicene is a low-dimensional material of interest to many scientists because of its structural properties that are compatible with silicon devices and opens up many new applications for technology. Silicene nanoribbons are one-dimensional structures, the silicene nanoribbons studied here have 12 silicon atoms inside, and the edges are edited by 4 hydrogen atoms per unit cell. There are two doped Sn atoms per unit cell of silicene nanoribbons, the three configurations studied here are ortho, meta, and para configurations. The system is placed in an external electric field of 0.4 V/Angstrom. Use density function theory (DFT) to calculate the formation energy, energy band structure, and state density of the system. The doped systems are stable after optimization. The presence of the external electric field and the doping element Sn is responsible for the changes in the structural properties of the system.

In English

It is known that titanium dioxide as photocatalyst has significant drawback - limited absorption spectrum in the ultraviolet region makes it impossible to use solar energy. To expands the absorption spectrum of TiO2, the doping of impurities (metal, non-metal, etc.) were used. They affected the electronic structure and spectral characteristics of TiO2. The aim of our work was to investigate the influence of tin impurities on spectral characteristics of titanium dioxide using experimental and theoretical methods. The TiO2 powders modified by different amount of tin (Sn/TiO2) were synthesized by sol-gel method. The samples were characterized by SEM, EDX, FT-IR and UV-VIS spectroscopy. It has been found that Sn/TiO2 consists of fragmented agglomerates in the range of 5–10 mm. EDX spectroscopy prove that powders include Ti, O and Sn elements. Modification of titanium dioxide with tin leads to band gap narrowing of samples, which explains by insertion of Sn atoms into crystal lattice of titanium dioxide, because Ti4+ and Sn4+ ions radii are close. The band gap values increased with increasing of tin content. The work also analyzes the vibrational spectra of Sn/TiO2 both experimentally and theoretically. In order to interpret the results obtained, quantum chemical calculations on the spatial and electronic structures of cluster models of titanium dioxide (anatase) with inserted tin atoms using the density functional theory B3LYP method and the basis set 6-31G (d, p) were carried out and the corresponding FT-IR spectra have been simulated. By comparing the experimental and theoretical results, the influence has been analyzed of the number and arrangement of impurity tin atoms in clusters on the observed IR spectra of the samples. This makes it possible to forgive the most probable structural motives of titanium dioxide particles doped with tin atoms, as well as to establish the fact of the presence of tin atoms in the samples. Based on the comparison of the IR spectra of samples with different numbers of tin atoms, it is possible to quantify their composition.

Elucidating the underlying surface chemistry of Sn/Al2O3 catalysts during the propane dehydrogenation in the presence of H2S co-feed

Incipient wetness impregnation was used to deposit dispersed tin (Sn) atoms on γ-Al2O3. The morphology and structure of the catalysts were characterized using Raman, X-ray Photoelectron Spectroscopy (XPS), and low energy ion scattering (LEIS) combined with N2-physisorption and in situ infrared diffuse reflectance spectroscopy (DRIFTS) using NH3 and CO2 as probe molecules, H2- temperature-programmed reduction (H­2-TPR), and steady-state reaction kinetics measurements. The effects of H2S on the surface chemical composition and structure of the resulting catalysts were systematically studied. The results showed isolated and well-dispersed Sn oxide sites of the deposited catalyst with nanoparticles observed only at relatively high coverages of 10% Sn at a coverage ranging from 0.48 to 2.8 Sn atoms nm−2. DRIFT spectroscopy evidenced a decrease in the number of Lewis acid sites on H2S treated Sn/Al2O3 suggesting surface tin species re-dispersing and blocking the active sites of γ-Al2O3. Overall, the surface analysis results presented here suggest that the active catalytic sites in the presence of H2S involve Al2O3 rather than bulk sulfide and Sn atoms dispersed over alumina towards propane dehydrogenation.

Dibutyltin(IV) complex of 2-[(E)-(4-hydroxy-3-{(E)-[(quinolin-2-yl)imino] methyl} phenyl) diazenyl]benzoic acid: Synthesis, spectroscopy and in vitro antifungal activity

ABSTRACT: Dibutyltin(IV) complex of 2-[(E)-(4-hydroxy-3-{(E)-[(quinolin-2-yl)imino] methyl} phenyl) diazenyl]benzoic acid was synthesized by refluxing 2-[(E)-(4-hydroxy-3-{(E)-[(quinolin-2- yl) imino] methyl} phenyl) diazenyl]benzoic acid with dibutyltin(IV) oxide in hot toluene. The complex was characterized by elemental analysis in combination with UV-visible, IR, 1H, 13C, 119Sn NMR spectroscopy and Mass spectrometry technique. The carboxylate ligand acts as chelating bidentate mode of coordination with the tin atom in the complex. The complex exhibited cyclic dimeric structure in the solution state where the tin centers adopt 6- coordinate octahedral geometry. The in vitro antifungal property of the ligand and the complex was observed and compared with reference drug, Amphotericin-B.

Chemistry of Some Organotin Compounds

Organotin compounds (OTCs) are characterized as having at minimum one covalent bond between carbon and tin atoms, and are usually denoted by the formula RnSnX4-n (n =1-3, R =aryl or alkyl, X =halogen ion or a carboxylate, etc.). There are several methods to synthesis organotin compounds, they are Grignard and Kocheshkov reactions, Wurtz reaction and alkylation method. The tin has two stable state,(II) and (IV). Sn(II) forms pyramidal sp3complexes as well as trigonal bipyramidal sp3d complexes, whereas Sn(IV) forms trigonal bipyramidal sp3d complexes or octahedral sp3d2complexes.

Tributyltin(IV) Butyrate: A Novel Epigenetic Modifier with ER Stress- and Apoptosis-Inducing Properties in Colon Cancer Cells.

Organotin(IV) compounds are a class of non-platinum metallo-conjugates exhibiting antitumor activity. The effects of different organotin types has been related to several mechanisms, including their ability to modify acetylation protein status and to promote apoptosis. Here, we focus on triorganotin(IV) complexes of butyric acid, a well-known HDAC inhibitor with antitumor properties. The conjugated compounds were synthesized and characterised by FTIR spectroscopy, multi-nuclear (1H, 13C and 119Sn) NMR, and mass spectrometry (ESI-MS). In the triorganotin(IV) complexes, an anionic monodentate butyrate ligand was observed, which coordinated the tin atom on a tetra-coordinated, monomeric environment similar to ester. FTIR and NMR findings confirm this structure both in solid state and solution. The antitumor efficacy of the triorganotin(IV) butyrates was tested in colon cancer cells and, among them, tributyltin(IV) butyrate (BT2) was selected as the most efficacious. BT2 induced G2/M cell cycle arrest, ER stress, and apoptotic cell death. These effects were obtained using low concentrations of BT2 up to 1 μM, whereas butyric acid alone was completely inefficacious, and the parent compound TBT was poorly effective at the same treatment conditions. To assess whether butyrate in the coordinated form maintains its epigenetic effects, histone acetylation was evaluated and a dramatic decrease in acetyl-H3 and -H4 histones was found. In contrast, butyrate alone stimulated histone acetylation at a higher concentration (5 mM). BT2 was also capable of preventing histone acetylation induced by SAHA, another potent HDAC inhibitor, thus suggesting that it may activate HDACs. These results support a potential use of BT2, a novel epigenetic modulator, in colon cancer treatment.

Synthesis, computational and biological studies of alkyltin(IV) N-methyl-N-hydroxyethyl dithiocarbamate complexes

Methyltin(IV) of butyltin(IV)–N-hydroxyethyl dithiocarbamate complexes, represented as [(CH3)2Sn(L(OH))2] and [(C4H9)2Sn(L(OH))2] respectively were synthesized and characterized using spectroscopic techniques (1H, 13C and 119Sn NMR) and elemental analysis. Both infrared and NMR data showed that, the complexes were formed via two sulphur atoms of the dithiocarbamate group. This mode of coordination was further supported by the DFT calculation, which suggested the formation of a distorted octahedral geometry around the tin atom. The complexes were screened for their antioxidant, cytotoxicity and anti-inflammatory properties. Four different assays including DPPH, nitric oxide, reducing power and hydrogen peroxides were used for the antioxidant studies, while an in vitro anti-inflammatory study was done using albumin denaturation assay. The complexes showed good antioxidant activity, especially in the DPPH assay. Butyltin(IV)–N-hydroxyethyl dithiocarbamate showed better cytotoxicity activity compared to methyltin(IV)–N-hydroxyethyl dithiocarbamate in the selected cell lines, which included KMST-6, Caco-2 and A549 cell lines. The anti-inflammatory activities revealed that the two complexes have useful activities better than diclofenac used as control drug.

In-situ Ti(C, N) reinforced AlCoCrFeNiSi-based high entropy alloy coating with functional gradient double-layer structure fabricated by laser cladding

In-situ Ti(C, N) reinforced AlCoCrFeNiSi-based high entropy alloy coating with functional gradient double-layer structure is successfully fabricated on the H13 substrate using laser cladding. The microstructures and wear resistance of the gradient coating are characterized using SEM, EBSD, TEM, EDS and wear test, respectively. The results show that FCC solid-solution matrix is formed in first layer, while a mixture of disordered BCC phase (Fe-Cr) and ordered B2 phase (Al-Ni-Ti) with coherent interface is found as the matrix in second layer. Ti(C, N) ceramic particles are in-situ synthesized in the coating due to the large negative mixing enthalpy of Ti-C and Ti-N atom pairs. The solid-solution strengthening and dislocation strengthening caused by the dissolution of Ti into B2 phase, accompanying with the fine grain strengthening caused by the microstructure refinement and dispersion strengthening of Ti(C, N) particles, contribute to the high surface hardness and wear resistance. The dominant wear mechanism of this coating is oxidation wear with a small amount of abrasive wear. It can be concluded that AlCoCrFeNiSi-based high entropy alloy coating with in-situ Ti(C, N) reinforcement dramatically improves the wear resistance of the H13 substrate.

The stannides Ca1.692Pt2Sn3.308, SrPtSn2 and EuAuSn2

Abstract Polycrystalline samples of the stannides Ca1.692Pt2Sn3.308, SrPtSn2 and EuAuSn2 were synthesized directly from the elements, using sealed tantalum ampoules as crucible material. The reactions were performed in muffle or induction furnaces. The phase purity of the samples was studied by X-ray powder diffraction (Guinier technique). The structures of Ca1.692Pt2Sn3.308 and SrPtSn2 were refined from single-crystal X-ray diffractometer data: NdRh2Sn4 type, Pnma, a = 1887.22(13), b = 441.22(3), c = 742.89(4) pm, wR = 0.0626, 1325 F 2 values, 45 variables for Ca1.692(8) Pt2Sn3.308(8) and CeNiSi2 type, Cmcm, a = 462.59(5), b = 1932.8(2), c = 458.00(5) pm, wR = 0.0549, 481 F 2 values, 18 variables for SrPtSn2. The calcium compound shows a homogeneity range Ca1+x Pt2Sn4−x with substantial Sn4/Ca2 mixing on one of the 4c Wyckoff positions. The [PtSn2] network is characterized by Pt–Sn (269–281 pm) and Sn–Sn (306–336 pm) bonding interactions. SrPtSn2 contains two different tin substructures: (i) Sn1–Sn1 zig-zag chains (282 pm) and (ii) orthorhombically distorted Sn2 squares (326 pm) with stronger and weaker Sn–Sn bonding. Together, the platinum and tin atoms build up a three-dimensional [PtSn2] network in which the platinum atoms have a distorted square-pyramidal tin coordination with Pt–Sn distances ranging from 261–270 pm. EuAuSn2 also crystallizes with the CeNiSi2-type structure with the lattice parameters a = 453.9(1), b = 2018.9(5) and c = 456.8(1) pm. Temperature dependent magnetic susceptibility studies indicate europium(II) with an experimental magnetic moment of 8.28(2) µB per Eu atom. EuAuSn2 is ordered antiferromagnetically at T N = 14.8(2) K. 151Eu Mössbauer spectra confirm the oxidation state +2 for europium (isomer shift δ = −11.17(2) mm s−1) and the magnetic ordering at low temperature (21.8 T magnetic hyperfine field at 6 K).

Abstract 1297: Synthesis and structural analysis on an ionic diphenyltin complex as a potential anticancer agent

Abstract Triorganotins are popular among chemists due to their potential biological properties against bacteria, fungi, and cancer cell lines. However, they have limited applications due to their poor water solubility. We hypothesize that solubility can be improved when the complex exhibits partial ionic characteristics. Therefore, it is our research goal to synthesize triphenyltin complexes that possess ionic characteristics. Syntheses of the ionic triphenyltin complex involved the reaction of a diprotic carboxylic acid, with triphenyltin chloride in the presence of di-isopropylamine. However, a tin-carbon cleavage reaction was observed, as IR/NMR spectroscopy and X-ray Crystallography studies showed that an ionic diphenyltin complex was successfully obtained in the reaction. The ionic complex consists of a diphenyltin anionic moiety, two oxalate ligands are observed coordinating to the tin atom in the bidentate mode, and two diisopropylammonium as the counterions. The anionic diphenyltin moieties has a distorted octohedral geometry with two carbons and two oxygens atom occupying the equatorial positions and two oxygen atoms occupying the axial positions. The ionic complex is essentially a 1-D polymer chain through an extensive hydrogen-bonding network between the oxalate groups (OCO) and the N atom from the ammonium cations. Compared to the similar reaction with triphenyltin hydroxide, which resulted in ionic triphenyltin complexes, cleavage of one phenyl group was observed for the first time in the reaction with triphenyltin chloride. Future studies will be focused on the mechanistic studies on the Sn-C cleavage. Citation Format: Jade Witter, Xueqing Song, Tajera Henry, William Li. Synthesis and structural analysis on an ionic diphenyltin complex as a potential anticancer agent [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1297.

Study on the mechanical and optical properties of SiSn alloy by first principles

Group-IV semiconductor alloys are important materials for in-chip and inter-chip optoelectronic applications in silicon-based high-performance large-scale integrated circuits. As photovoltaic materials, silicon–tin alloys can improve the performance of solar cells by expanding the spectral range and increasing absorption. Silicon–tin alloys have broad application prospects within the communication wavelength range of 1.0–1.6 µm. In this work, the lattice constants, mechanical and optical properties of Si32−xSnx alloy are calculated. Generalized gradient approximation with Hubbard correction parameter U was used for exchange-correlation potential. The calculation results demonstrate that the lattice constant and formation energy increase with increasing number of tin atoms. In terms of mechanical properties, Si32−xSnx alloy shows mechanical stability and strong resistance to resist external forces, and it is not prone to volume deformation. It shows metallicity and tends to be ductile. In terms of optical properties, the width of the bandgap of Si32−xSnx alloy decreases with increasing tin concentration. The absorption of visible and infrared lights of Si32−xSnx alloy increases with increasing tin concentration. The dielectric properties of Si32−xSnx alloy are significantly changed by the addition of tin atoms. Doping prolongs the carrier lifetime of Si32−xSnx alloy, and its lifetime reaches maximum when x equals 6.

Fused hexacyclic organotin(IV) compounds derived from 3-[((2-hydroxynaphthalen-1-yl)methylene)amino]naphthalen-2-ol

The ligand E-3-[((2-hydroxynaphthalen-1-yl)methylene)amino]naphthalen-2-ol (H2L) and its organotin(IV) complexes (Me)2Sn(H2L) (1a), (n-Bu)2Sn(H2L) (1b), (Ph)2Sn(H2L) (1c), (n-Oct)2Sn(H2L) (1d), (Cy)2Sn(H2L) (1e), and (Me3SiCH2)2Sn(H2L) (1f)] have been synthesized in one pot by multicomponent reactions in moderate yields from 2‑hydroxy-1-naphthaldehyde, 3-amino-2-naphthol and the corresponding diorganotin(IV) oxide. The complexes were characterized by common spectroscopic techniques such as FT-IR, UV–vis, mass spectrometry and NMR (1H, 13C and 119Sn) spectroscopy analysis. 119Sn NMR spectra showed signals between δ = - 143 to -323 ppm for all compounds, indicating the pentacoordination of the tin atoms in solution. Single X-ray structure of complex 1a show a distorted octahedral geometry for tin atoms because of the presence of intermolecular Sn•••O interactions. 1D polymeric structures are formed by CH•••O and CH•••π interactions in solid state.

In-plane strain-free stanene on a Pd2Sn(111) surface alloy

Here we report the growth of laterally strain-free stanene, that is a two-dimensional (2D) honeycomb structure of tin atoms, on a Pd(111) crystal terminated by a ${\mathrm{Pd}}_{2}\mathrm{Sn}$ surface alloy. The atomic geometry and the electronic structure have been thoroughly investigated by scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), Auger electron spectroscopy, high-resolution synchrotron radiation photoemission spectroscopy, and advanced first principles calculations. The STM images clearly reveal the epitaxial growth of honeycomb stanene on the preformed ${\mathrm{Pd}}_{2}\mathrm{Sn}$ surface alloy. LEED patterns clearly show commensurate (\ensuremath{\surd}3\ifmmode\times\else\texttimes\fi{}\ensuremath{\surd}3)R30\ifmmode^\circ\else\textdegree\fi{} spots, corresponding to a lattice constant of 0.47 nm, in perfect accord with the cell size of free-standing stanene. The measured very low buckling, within 20 pm, is derived from section profiles of atomic-scale STM images. This contrasts the significantly larger buckling of free-standing stanene, possibly due to a STM tip effect as well as a non-negligible interaction with the underlying surface alloy. The electronic structure exhibits a characteristic 2D band with parabolic dispersion, which is in good accordance with electronic structure calculations in density functional theory.

Molecular Dynamics Simulations of the Thermal Conductivity of Silicon-Germanium and Silicon-Germanium-Tin Alloys

In this work, we investigate the thermal conductivity properties of Si 1 − x Ge x and Si 0.8 Ge 0 Sn 2 y alloys. The equilibrium molecular dynamics (EMD) is employed to calculate the thermal conductivities of Si 1 − x Ge x alloys when x is different at temperatures ranging from 100 K to 1100 K. Then nonequilibrium molecular dynamics (NEMD) is used to study the relationships between y and the thermal conductivities of Si 0.8 Ge 0.2 Sn 2 y alloys. In this paper, Ge atoms are randomly doped, and tin atoms are doped in three distributing ways: random doping, complete doping, and bridge doping. The results show that the thermal conductivities of Si 1 − x Ge x alloys decrease first, then increase with the rise of x , and reach the lowest value when x changes from 0.4 to 0.5. No matter what the value of x is, the thermal conductivities of Si 1 − x Ge x alloys decrease with the increase of temperature. Thermal conductivities of Si 0.8 Ge 0.2 alloys can be significantly inhibited by doping an appropriate number of Sn atoms. For the random doping model, thermal conductivities of Si 0.8 Ge 0.2 Sn y alloys approach the lowest level when y is 0.10. Whether it is complete doping or bridge doping, thermal conductivities decrease with the increase of the number of doped layers. In addition, in the bridge doping model, both the number of Sn atoms in the [001] direction and the penetration distance of Sn atoms strongly influence thermal conductivities. The thermal conductivities of Si 0.8 Ge 0.2 Sn y alloys are positively associated with the number of Sn atoms in the [001] direction and the penetration distance of Sn atoms.

Study of layered system Fe3Sn2-a-Fe(Sn) obtained by ion-plasma sputtering and thermal annealing

Thin Armco Iron foils with a Tin coating deposited by ion-plasma sputtering and subjected to isothermal annealing at 650°C have been studied by Mössbauer spectroscopy. The formation of intermetallic compounds FeSn and Fe 3Sn 2, as well as a solid solution of Tin atoms in a-Fe(Sn), was revealed. The possibility of obtaining a thermally stable layered spatially inhomogeneous Fe 3Sn 2-a-Fe(Sn) system is shown.

<i>In Silico</i> Biological Profile Prediction of Some Selectively Synthesized Acyl Rhamnopyranosides

Over the past several decades significant biological activities including brains protective and antimicrobial activities have made sugar esters (SEs) as a topic of great interest. In this context, unimolar 3-chlorobenzoylation of methyl α-L-rhamnopyranoside (4) using dibutyltin oxide method regioselectively furnished only the 3-O-substitution product 5 in excellent yield. The reaction proceeded via the formation of a cyclic 2,3-O-dibutylstannylene intermediate where equatorial hydroxyl group is activated by the tin atom leading to the formation of product 5 only. To get biologically important rhamnopyranoside esters chlorobenzoate 5 was further converted into three newer 2,4-di-O-acyl products 6-9 with other acylating agents using direct acylation method. Prediction of activity spectra for substances (PASS) indicated that these rhamnopyranoside esters have many promising biological profiles including CYP2H substrate, membrane permeability inhibitor and better antifungal activities. Additionally, ADMET and drug likeness properties of SEs 5-8 were predicted and discussed.

Fluorine-surface-modified tin-doped hematite nanorod array photoelectrodes with enhanced water oxidation activity

Severe charge recombination and sluggish water oxidation reaction (OER) kinetics significantly limit the practical application of hematite in photoelectrochemical (PEC) water-splitting devices. In this study, fluorine-surface-modified tin-doped hematite (F/Sn:Fe2O3) photoelectrodes have been fabricated by a hydrothermal method incorporated impregnation annealing process. The grown FeOOH nanorods coated with NH4F solution are annealed first at 550 °C in the vacuum to modify the hematite surface and then at 750 °C in argon to promote the diffusion of tin atoms from the fluorine-doped tin oxide (FTO) glass substrate to the hematite structure. The synergistic effect of F-modification and Sn-doping on Fe2O3 electrode considerably enhances its PEC water oxidation performance, resulting in the highest photocurrent density of 3.64 mA cm−2 at 1.23 V vs. reversible hydrogen electrode (RHE) under AM 1.5 G illumination. Both effects increase the carrier concentration in the photoelectrode, which improves its transport efficiency. Moreover, the surface-localized F species promote the OER process on the electrode surface and improve the charge separation at the electrode/electrolyte interface by increasing its hole supply rate under the increased electric field. This work may open a new avenue for fabricating novel photoelectrodes with high PEC water splitting efficiency.

Vapochromic Luminescent π-Conjugated Systems with Reversible Coordination-Number Control of Hypervalent Tin(IV)-Fused Azobenzene Complexes.

The dynamic and reversible changes of coordination numbers between five and six in solution and solid states, based on hypervalent tin(IV)-fused azobenzene (TAz) complexes, are reported. It was found that the TAz complexes showed deep-red emission owing to the hypervalent bond composed of an electron-donating three-center four-electron (3c-4e) bond and an electron-accepting nitrogen-tin (N-Sn) coordination. Furthermore, hypsochromic shifts in optical spectra were observed in Lewis basic solvents because of alteration of the coordination number from five to six. In particular, vapochromic luminescence was induced by attachment of dimethyl sulfoxide (DMSO) vapor to the coordination point at the tin atom accompanied with a crystal-crystal phase transition. Additionally, the color-change mechanism and degree of binding constants were well explained by theoretical calculation. To the best of our knowledge, this is the first example of vapochromic luminescence by using stable and variable coordination numbers of hypervalent bonds.

Guanidinium tin halide perovskites: structural, electronic, and thermodynamic properties by quantum chemical study

The orthorhombic phase of guanidinium tin halide perovskites C(NH2)3SnX3, X = Cl, Br, I has been studied by quantum chemical method. The lattice parameters are optimized to obtain the minimum energy using the density functional theory with the generalized gradient approximation, GGA-PBE. The Kohn–Sham electronic band structures have been computed; the materials have direct bandgaps of 3.00, 2.47, and 1.78 eV for the C(NH2)3SnCl3, C(NH2)3SnBr3, and C(NH2)3SnI3, respectively, situated at the gamma symmetry points. The projected densities of states are analyzed and the contribution of the p- and s-states of the tin and halogen atoms evaluated. For the GUASnX3 compounds, thermodynamic stability to different decomposition routes has been assessed and standard enthalpies of formation obtained.