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Background: Gentian violet dye released from industries into the environment has caused serious water pollution and is a significant environmental pollutant to human beings owing to the toxicity. It is urgent to decrease environmental pollution by removing gentian violet in the wastewater. Objective: The aim is to synthesize hexahydroxy strontium stannate/tin dioxide nanocomposites by a simple hydrothermal method without surfactants and research the photocatalytic performance for gentian violet degradation. Methods: Hexahydroxy strontium stannate/tin dioxide nanocomposites have been obtained via the hydrothermal method. The structure, size, morphology and photocatalytic performance were characterized by X-ray diffraction, electron microscopy, solid ultraviolet-visible diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. Results: The nanocomposites possess oven-shaped morphology with the size of less than 100 nm and are composed of hexagonal SrSn(OH)6 and tetragonal SnO2 phases. The band gap of the nanocomposites is 3.52 eV. 10 mg hexahydroxy strontium stannate/tin dioxide nanocomposites have the ability to completely degrade 10 mL gentian violet solution with the concentration of 10 mgL-1 under 6 h ultraviolet-visible light irradiation. Hydroxyl radical, hole and superoxide radical are the main species for the gentian violet photocatalytic degradation using the nanocomposites. Conclusion: The hexahydroxy strontium stannate/tin dioxide nanocomposites show good photocatalytic performance for the GV degradation. The photocatalytic performance for gentian violet degradation using the hexahydroxy strontium stannate/tin dioxide nanocomposites depends on the irradiation time and content of the nanocomposites.

To seek more feasible catalysts for OCM reaction, SrSnO3, Sr2SnO4 and Sr3Sn2O7 perovskite compounds have been purposely designed and synthesized. It is discovered that the fine crystal structure change influences the reaction performance of the catalysts significantly, which follows the order of Sr2SnO4 > Sr3Sn2O7 > SrSnO3. On these perovskite catalysts, both the electrophilic chemisorbed O2–/O22– and surface lattice O2– species are active and selective for C2 product formation. In addition, both of their moderate and strong surface basic sites contribute vitally to the reaction. It is found that the moderate sites are associated with the M+−O- ion pairs and oxygen vacancy, and the strong basic sites are related to the coordinatively unsaturated surface lattice O2–. Due to the phase structure difference of the three perovskites, their Sn-O bond length changes in the order of Sr2SnO4 > Sr3Sn2O7 > SrSnO3. Furthermore, both the electrical conductivity and DFT calculation results have testified that it is easier for Sr2SnO4 to generate surface oxygen vacancies than Sr3Sn2O7 and SrSnO3, which explains that this sample has the largest quantities of active surface oxygen and basic sites, as well as the best OCM performance.

Transition metals doping has been proved to be a feasible way for tuning the physical properties on the surface and bulk of nanomaterials and also for the good performance in decontamination of emerging pollutants. In this context, doped samples of zinc tin oxide or zinc stannate nanoparticles (ZTO NPs) by several transition metals were synthesized in order to enhance the optical absorbance with the aims of reducing the band gap and therefore ameliorated their photocatalytic activity. They were characterized by the X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy, Raman spectroscopy and photoluminescence. The XRD patterns and the microscopic observations showed the formation of spherical nanoparticles with an average size of about 30 nm and highly pure ZTO phase with an inverse spinel structure. The Raman spectra were dominated by bands relatives to the F2g (2) and A1g symmetries modes of inverse spinel structure. The band gap Eg is estimated to be 3.75 eV for the undoped sample, and 3.67, 3.64, 3.78 and 3.21 eV, for 2% Fe, 2% Mg, 2% Gd, and 2% Mn doped ZTO samples, respectively. Furthermore, the undoped ZTO NPs have the intrinsic problem of recombination of photogenerated charge carriers. We have shown that the reduction of the band gap and oxygen vacancies resulting from the doping effect could be a useful tool for trapping and avoid the recombination of electrons coming from photosensitized rhodamine B (RhB) under visible light irradiation. Owing to the structural advantages and low band gap, 2% Mn doped ZTO NPs, with the kinetic rate constants k of 0.024 min−1, show enhanced performance for the elimination of RhB in aqueous solution compared to undoped and other doped ZTO NPs.

The frequency and full width at half maximum (FWHM) data of the Ag Raman modes (95.4, 231.4 and 263.2 cm−1) in strontium stannate crystal have been analyzed using the Balkanski model and the fittin...

This study reports the structure, optical and electrical properties of spin coated Zn2−xCdxSnO4 films. The structure–property relationship was investigated by X-ray diffraction (XRD), field emission scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), UV–VIS–NIR spectroscopy and Hall measurements. XRD study revealed the preferential growth along (311) for inverse spinel structured zinc stannate films. The modulation of granular surface morphology with Cd content has been observed. The broadening of F2g(3) mode and intensity enhancement of Eg mode at the expense of A1g mode for Zn2SnO4 system with Cd content has been observed. Chemical structure and charge states of the participating atoms were confirmed by XPS technique. The optical gap and optical transparency decreases with Cd content. The decrease in carrier mobility was found to dominate on an enhancement in carrier concentration to offer slight decrease in the electrical resistivity of Cd-doped films. Figure of merit has also been calculated with Cd content. These results are important for furthering the development and applications of these materials for future transparent electronics.

Herein, we describe the synthesis, full spectroscopic characterization, DFT (density functional theory) calculations, and single-crystal X-ray diffraction analyses of a series of osmium arene sigma-germyl, germanate, sigma-stannyl, and stannate complexes, along with their cytotoxic (anticancer) investigations. The known dimer complexes [OsCl2(eta(6)-C6H6)](2) (1) and [OsCl2(eta(6)-p-cymene)](2) (2) were reacted with PPh3 to form the known mononuclear complex [OsCl2(eta(6)-p-cymene)(PPh3)] (3) and the new complex [OsCl2(eta(6)-C6H6)(PPh3)] (6); complex 3 was reacted with GeCl2 center dot(dioxane) and SnCl2 to afford, by insertion into the Os-Cl bond, the neutral sigma-germyl and stannyl complexes [OsCl(eta(6)-p-cymene)(PPh3)(GeCl3)] (7) and [OsCl(eta(6)-p-cymene)(PPh3)(SnCl3)] (11), respectively, as a mixture of enantiomers. Similarly, the reaction of complex 6 with GeCl2 center dot(dioxane) afforded [OsCl(eta(6)-C6H6)(PPh3)(GeCl3)] (9). Complex 2, upon reaction with 1,1-bis(diphenylphosphino)methane (dppm), formed a mixture of [OsCl2(eta(6)-p-cymene)(kappa(1)-dppm)] (4) and [Os(eta(6)-p-cymene)(kappa(2)-dppm)Cl]Cl-+(-) (5) when prepared in acetonitrile and a mixture of 4 and the dinudear complex [[OsCl2(eta(6) -p-cymene)](2) (mu-dppm)] (0) when prepared in dichloromethane. By utilizing either isolated 4 or a mixture of 4 and 5, the synthesis of kappa(2)-dppm germanate and stannate salts, [OsCl(eta(6)-p-cymene)(kappa(2)-dppm)]+GeCl3- (8) and [OsCl(eta(6)-p-cymene)(kappa(2)-dppm)]+SnCl3- (10), were accomplished via halide-abstracting reactions with GeCl2 center dot(dioxane) or SnCl2, respectively. All resulting complexes were characterized by means of multinuclear NMR, FT-IR, ESI-MS, and UV/Vis spectroscopy. X-ray diffraction analyses of 4, 8, 9, 10, and 11 were performed and are reported. DFT studies (B3LYP, basis set LANL2DZ for Os, and def2-TZVPP for Sn, Ge, Cl, P, C, and H) were performed on complex 9 and the benzene analogue of complex 11, 11-benzene, to evaluate the structural changes and the effects on the frontier molecular orbitals arising from the substitution of Ge for Sn. Finally, complexes 3 and 7-11 were investigated for potential anticancer activities considering cell cytotoxicity and apoptosis assays against Dalton's lymphoma (DL) and Ehrlich ascites carcinoma (EAC) malignant cancer cell lines. The complexes were also tested against healthy peripheral blood mononudear cells (PBMCs). All cell lines were also treated with the reference drug cisplatin to draw a comparison with the results obtained from the reported complexes. The study was further corroborated with in silica molecular interaction simulations and a pharmacokinetic study.

The flexible polyurethane foam (FPUF) has been modified with the flame-retardant system of strontium stannate (SrSnO3) and ammonium polyphosphate (APP). Synergistic effect of SrSnO3 and APP on flam...

Various excellent properties of rare earth zirconate and stannate pyrochlores are close related with their native point defects. First-principles calculations are performed to systematically investigate the point defect mechanism and the oxygen diffusion behavior of A2B2O7 (A=La, Ce, Pr, Nd, Pm, Sm, Eu, Gd; B=Zr, Sn). The possible defect complexes and their associated reactions under stoichiometric and nonstoichiometric conditions are explored. The O Frenkel pairs are the most stable defect structure in stoichiometric zirconates, whereas the cation antisite defects are the predominant one in stoichiometric stannates. In the case of BO2 excess zirconates and stannates, the BA cation antisite defect with the A vacancy and/or the oxygen interstitial is energetically favorable, whereas the AB antisite defect together with the oxygen vacancy and/or the A interstitial is preferable under the A2O3 excess condition. Meanwhile, the maximum point defect concentrations of zirconates are much higher than those of stannates. Furthermore, the oxygen migration barriers are similar in these compounds, ranging in 0.68 eV∼ 0.80 eV. The predicted point defects and oxygen diffusion mechanisms play the critical role in their engineering applications and are expected to guide the future property improvement of pyrochlores through the control of point defects and/or composition.

In this paper, dysprosium stannate-nanostructured thin films (Dy2Sn2O7) were deposited by spray pyrolysis method on fused silica substrates at T = 480 °C. A solution of 0.1 molar tin(IV) chloride pentahydrate (SnCl4⋅5H2O) and dysprosium(III) nitrate with mole ratios of [Dy/Sn] % = 10, 30, 50, 70, and 100% was used to prepare dysprosium stannate-nanostructured thin films (Dy2Sn2O7) by spray pyrolysis method. Then, the effect of Dy-content and annealing temperature in air at T = 500, 600, 1100 and 1200 °C, on structural conversion and optical properties were investigated for these films. The X-ray diffraction (XRD) patterns indicated that the dominant phase above T = 1100 °C is pyrochlore phase of dysprosium stannate. The field emission scanning electron microscopy (FE-SEM) images showed the formation of nanocrystals of dysprosium stannate with pyrochlore structure. The FE-SEM images show that the surface morphologies of as-prepared films are in the form of cubic nanocrystals before annealing and nano-polyhedral as agglomerated after annealing at T = 1200 °C. The results of UV–Vis analysis indicated that with increasing the Dy-content and annealing at T = 1200 °C, optical transmittance and bandgap was increased. The optical bandgap for ratios of [Dy/Sn] = 50 and 100% were obtained 2.65 and 2.76 eV, respectively, after annealing at T = 1200 °C.

Doped metal oxide nanocrystals (NCs) exhibit tunable localized surface plasmon resonances (LSPRs) in the infrared spectral region. Compared to the binary oxides commonly studied, plasmonic NCs deri...

Zinc stannate (Zn2SnO4), zinc ferrite (ZnFe2O4), zinc antimonate (ZnSb2O4) and zinc aluminate (ZnAl2O4) are examples of zinc-based two-cation oxide spinel semiconductors (ZTCOSSs) that have been investigated and employed in many applications. These include applications in solar cells, photocatalysts, batteries, supercapacitors, thermoelectrics and sensors. Zinc-based two-cation oxide spinel semiconductors have peculiar properties that include low electrical resistivity and unique optics. Also, ZTCOSSs permit multiple redox reactions and exhibit magnetic properties depending on the cations. ZTCOSS has the advantages of better optical, electrical and chemical properties over the zinc oxide spinel semiconductor. In this review, the concept of zinc-based two-cation spinel oxides, fabrication techniques and their properties are discussed. Applications of zinc-based two-cation oxide spinel semiconductors are explored and the performance compared with that of single oxides spinel semiconductors.

C25H23Br2Cl3N2Sn, monoclinic, P21/c (no. 14), a = 10.9372(1) Å, b = 23.1045(1) Å, c = 11.1856(1) Å, β = 106.942(1)°, V = 2703.91(4) Å3, Z = 4, R gt (F) = 0.0167, wR ref(F 2) = 0.0393, T = 100 K.

Er2Sn2O7 pyrochlore was irradiated with swift heavy Au ions (2.2 GeV), and the induced structural modifications were systematically examined using complementary characterization techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), and neutron total scattering with pair distribution function (PDF) analysis. Each technique probes different aspects and length scales of the transformed material regions. TEM revealed a core–shell ion track structure—an amorphous core surrounded by a disordered, anion-deficient fluorite shell—which was confirmed by XRD. Neutron total scattering, with sensitivity to the oxygen sublattice, provided relative fractions of amorphous and disordered fluorite phases and confirmed the presence of a defective pyrochlore phase, which largely maintains its structural ordering but is clearly distinct from the pristine pyrochlore matrix. This defect-rich pyrochlore phase forms a halo extending radially beyond the well-characterized core–shell track morphology observed in electron micrographs. Despite their differing long-range periodicity, the short-range structures of the amorphous, disordered, and defective pyrochlore phases are all modeled well with a weberite-type configuration. Evolution of the phase fractions with increasing ion fluence was examined to ascertain the phase-to-phase pathways that occur during primary and secondary ion impact. This approach extends knowledge about the multi-scale response of stannate pyrochlores to swift heavy ion irradiation in the electronic energy loss regime and improves existing track-overlap models.

The non-enzymatic electrochemical detection of glucose and aqueous ammonia was carried out using ternary bio-nanocomposites. A co-precipitation method was employed to synthesize cadmium stannate nanoparticles, while bio-nanocomposites of polyaniline–cadmium stannate–chitosan were synthesized via the chemical oxidative polymerization technique. Functional group analysis, structural and morphological studies were further carried out via Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning and transmission electron microscopy techniques. The electrode kinetics and electrochemical properties were validated via cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and chronoamperometric techniques. The sensing properties of the electrocatalysts were explored using cyclic voltammetry and amperometry for the detection of glucose and ammonia solution of varying concentrations using NaOH electrolyte. The electrochemical activity of the electrocatalysts were optimized using different weight percentages of chitosan, and bio-nanocomposites of polyaniline/cadmium stannate/chitosan (10%) showed excellent electrocatalytic and electrochemical activities. Moreover, the bio-nanocomposites have a low detection limit and short response time toward different concentrations of glucose and ammonia solution. Apart from these studies, the sensors have also been evaluated for an anti-interference study. The developed novel sensors present significant potential to be efficiently utilized on a large scale, as they also show effective stability and reproducibility, along with a high level of sensitivity for the given target analytes.

Наноструктуры станната цинка были синтезированы гидротермальным методом, в качестве исходных материалов были использованы наностержни оксида цинка. Образование многокомпонентных оксидов было исследовано с помощью рентгеновской фотоэлектронной спектроскопии. Установлено, что в процессе гидротермального синтеза происходит постепенное встраивание ионов олова в кристаллическую решетку наностержней оксида цинка и замещение ионов цинка. с образованием наноструктур станната цинка. Исследование влияния времени синтеза на химический состав поверхности полученных образцов показало, что формирование станната цинка происходит через 1 час, что подтверждается изменением энергий связи цинка и кислорода. При более длительном синтезе происходит разрушение наноструктур станната цинка, оксидов цинка и олова на поверхности образца практически не наблюдается. Zinc stannate nanostructures were synthesized by hydrothermal method, and zinc oxide nanorods were used as starting materials. Formation of multicomponent oxides was studied by using the X-ray photoelectron spectroscopy. It was found that tin ions are gradually embedded in the crystal lattice of zinc oxide nanorods and replaced zinc ions during hydrothermal synthesis with the formation of zinc stannate nanostructures. The study of the synthesis time effect on the surface chemical composition of the prepared samples has shown formation of zinc stannate after 1 hour, that is confirmed by changes in the binding energies of zinc and oxygen. With a longer synthesis, zinc stannate nanostructures collapsed, thus zinc and tin oxides are practically not observed on the sample surface.

In modern farming, pesticides are extensively used to deliver high-yield harvests with no concern about the amount of toxicity involved in the agriculture process. The continuous usage of pesticide...

We report ultra-selective zinc stannate nano cubes (ZnSnO3) modified glassy carbon electrode (GCE) for simultaneous detection of Uric Acid (UA) and Dopamine (DA) using differential pulse voltammetry (DPV) technique. The ZnSnO3 nano cubes were synthesized via one-pot hydrothermal technique. The orthorhombic phase formation of nano cubes structured ZnSnO3 was confirmed through X-ray diffraction (XRD) and scanning electron microscopy (SEM) imaging. The sensor exhibited very distinct oxidation potentials and excellent sensitivity with wide dynamic ranges of detection ranging from 10 nM to $5~\mu \text{M}$ and $1~\mu \text{M}$ to 5 mM with a very low limit of detections of 2.6 nM and 550 nM towards DA and UA respectively. The sensing mechanism can be ascribed to the simultaneous electro-oxidation process of DA and UA at the 3d orbital SnO6 octahedra sites facilitated with the Sn2+/Sn4+ oxidation states of Sn in line with the stress induced electrical property transformation of ZnSnO3 due to its piezoelectric nature. The as fabricated ZnSnO3/GCE sensor was further successfully evaluated for simultaneous detection of UA and DA in the simulated blood serum samples. This simple strategy for developing ZnSnO3 perovskite modified electrode paves way to develop electrochemical sensing platforms for bioanalytical applications.

Cubic perovskite oxides are attracting wide attention for applications in electronics and optoelectronics due to their high electronic mobility, however, realization of p-type conductivity in these oxides is still a matter. Barium stannate (BaSnO3) is one of such materials, wherein low-amount of lanthanum-doping can induce an extremely high room-temperature electron mobility. In this work, anion-doping strategy was explored to realize the p-type conductivity in BaSnO3, and the underlying physics of transport was investigated. It is found that nitrogen substitution for oxygen can induce the p-type conductivity in BaSnO3 thin films. By analyzing the temperature-dependent resistance and negative magnetoresistance data, Efros-Shklovskii variable-range hopping conduction is identified as the dominant transport mechanism in p-type BaSnO3 thin films. Additionally, nitrogen-doped BaSnO3 homojunctions exhibit good rectifying and photo-response properties. This study provides an alternative strategy for realizing the p-type conductivity in stannate-based perovskite oxides, and is helpful for designing the properties of stannate-based devices.

The title structure consists of isolated [SnCl6]2− octa­hedral anions separated by layers of organic 1-(prop-2-en-1-yl)-1H-imidazol-3-ium (C6H9N2)+ cations. The crystal packing features inter­molecular N—H⋯Cl and C—H⋯Cl hydrogen bonds and π–π stacking inter­actions., A new 0D organic–inorganic hybrid material bis­[1-(prop-2-en-1-yl)-1H-imidazol-3-ium] hexa­chlorido­stannate(IV), (C6H9N2)2[SnCl6], has been prepared and characterized by single-crystal X-ray diffraction, Hirshfeld surface analysis and UV–visible spectroscopy. The structure consists of isolated [SnCl6]2− octa­hedral anions separated by layers of organic 1-(prop-2-en-1-yl)-1H-imidazol-3-ium cations. The 1-(prop-2-en-1-yl) fragment in the organic cation exhibits disorder over two sets of atomic sites having occupancies of 0.512 (9) and 0.488 (9). The crystal packing of the title compound is established by inter­molecular N/C–H⋯Cl hydrogen bond and π– π stacking inter­actions. Hirshfeld surface analysis employing three-dimensional mol­ecular surface contours and two-dimensional fingerprint plots has been used to analyse the inter­molecular inter­actions present in the structure. The optical properties of the crystal were studied using UV–visible absorption spectroscopy, showing one intense band at 208 nm, which is attributed to π–π* transitions in the cations.

Introducing a zinc stannate, ZnSnO3 (ZTO), layer on hydrothermally grown 3D-zinc oxide (ZnO) nanosheet thin films has been proven to have a quenching effect on the photoluminescence emissions, indicating very slow recombination of photoinduced electron-hole pairs in photoelectrochemical water splitting (PEC) reactions. Motivated by this, the ZnO/ZTO bilayer system has been used as the electron transport layer for copper indium gallium sulfide (CIGS)-based photoelectrodes in PEC applications. Furthermore, the poor photoresistivity of CIGS has been improved via indium sulfide (In2S3) deposition. Consequently, the photoelectrode obtained from the inverted configuration, ZnO/ZTO/CIGS/In2S3, has generated a photocurrent density of 6.4 mA cm-2 at 0.4 V (vs Ag/AgCl), exceeding the performance of ZnO NS/CIGS/In2S3 photoelectrodes by three folds. The highest ABPE and IPCE efficiencies have been calculated as 4.2% and 57%, respectively. More importantly, two cost-effective nonvacuum techniques for large-scale thin film fabrications such as chemical bath deposition (CBD) and ultrasonic spray pyrolysis (USP) methods have been adopted to acquire photoelectrodes with inverted configurations providing an advantageous approach for low-cost photoelectrode design for sustainable energy production. Copyright © 2020 American Chemical Society.

Fabrication of gate-recessed SrSnO3 (SSO) metal-semiconductor field-effect transistors (MESFETs) with Ni Schottky gates is reported on bi-layer epitaxial SSO films with a thin heavily-doped cap layer. Devices with 0.5- $\mu \text{m}$ gate length showed enhancement-mode behavior with a saturation drain current, ${I}_{\text {DSAT}}$ , of 33 mA/mm and peak transconductance, ${g}_{\text {m,max}}$ , of 65 mS/mm. The ${g}_{\text {m,max}}$ value is a roughly $2\times $ improvement over control devices fabricated on single-layer films. Gate-recessed SSO MESFETs with Pt Schottky gates were also explored on the bi-layer films. Devices with 1- $\mu \text{m}$ gate length displayed ${I}_{\text {DSAT}} =133$ mA/mm and $g_{\text {m,max}} =73$ mS/mm, after thermal annealing.

The zinc (Zn)-type compound zinc stannate (Zn2SnO4) is critical in the field of thin-film solar cells and photocatalysis. In this study, a new composite nanomaterial zinc stannate/tin (IV) oxide (SnO2) was synthesised through a high-temperature synthesis spray process. The electrochemical properties of the samples were tested. Besides, different ratios of zinc stannate/tin (IV) oxide nano-heterostructures were synthesised by using the ion exchange method, with zinc stannate nanocrystals as substrates. Also, their photocatalytic activities in a three-electrode system of simulated solar light sources were discussed. The photoelectric property of zinc stannate/tin (IV) oxide obtained from the solvothermal method was tested. The photocurrent of the obtained zinc stannate/tin (IV) oxide thin-film reached 2.6 μA, while the photocurrent of the zinc stannate thin film was only 0.13 μA. In the meantime, the fluorescence spectrum test proved that the recombination of zinc stannate and tin (IV) oxide reduced the recombination of photo-generated carriers. The photocatalytic test of zinc stannate/tin (IV) oxide obtained from the ion exchange method showed that given a 0.5 V reversible hydrogen electrode, the photocurrent of zinc stannate/tin (IV) oxide reached 0.62 mA/cm2. This indicator was 10 times the value of pure zinc stannate photocurrent under the same condition, which showed an increase in the photocatalytic capacity of zinc stannate. It proved that zinc stannate/tin (IV) oxide composite nanomaterials have better photoelectric performances and application prospects in the fields of solar cells and photocatalysis.

Lithium stannate (Li2SnO3) is currently being considered as a material for electrode and electrode coating applications in Li-ion batteries. The intrinsic defect formation and Li-ion transport prop...

Tilting of oxygen octahedra in perovskite is known to deteriorate the transparent conducting oxide (TCO) properties of perovskites. Traditional wisdom suggests that doping with an ion of larger size can reduce this tilting in stannates. In this study, we show that doping with smaller La-ion at Sr-site in SrSnO3 can also lead to a reduction in tilting, thereby improving the transport properties of the material. Structural and optical properties of La-doped strontium stannate (LaxSr1−xSnO3, with x = 0, 0.03 and 0.07) bulk, powder samples are presented. Rietveld refinement of the x-ray diffraction pattern was performed. A reduction in oxygen octahedral tilting with La-doping was observed from the refinement results. As a result of this reduction in oxygen octahedral tilting, changes in Sn–O and Sr–O bond lengths were observed. X-ray photoelectron spectroscopy (XPS) revealed that Sn4+ reduces to Sn2+ to balance the charge neutrality. The percentage contribution of Sn2+ was found to increase with doping, which suggests that La-dopant generates n-type conductivity in the material. Valence band spectroscopy (VBS) shows the n–type nature of the samples. Raman and Fourier transform infrared spectroscopy results support the XRD results, exhibiting a blue shift in their bands, which is attributed to the change in bond lengths and consequently, to a reduction in the tilting. Optical properties were studied by UV–Vis spectroscopy. The materials are transparent in the visible range, with bandgaps in the range of 3.87–3.97 eV.

The packing of the title mol­ecular salt, in which the tin atom lies on a crystallographic inversion centre, is dominated by N—H⋯Cl hydrogen bonds., In the title mol­ecular salt, (C5H7N2)2[SnCl6], the cation is protonated at the pyridine N atom and the complete dianion is generated by a crystallographic centre of symmetry. In the crystal, N—H⋯Cl hydrogen bonds link the components into a three-dimensional network built up from the stacking of alternate cationic and anionic layers. The nature of the inter­molecular inter­actions has been analysed in terms of the Hirshfeld surfaces of the cations and the anions. The thermal behaviour and the Raman spectrum of the title compound are reported.