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A tin(IV) chloride promoted (3 + 2) annulation of trans-2-aroyl-3-styrylcyclopropane-1,1-dicarboxylates with nitriles is reported. The transformation involves the Lewis acid assisted formation of 1,5-dipolar intermediates from the cyclopropane dicarboxylates and nitriles followed by cyclization. The reactions proceed in a highly diastereoselective manner and afford 5-vinyl-1-pyrroline derivatives in 60–88% yields.

A synthesis of a series of novel fused tricyclic heterocyclic compounds has been achieved in one-pot reaction set up starting from (E)-3-(2-oxo-2-phenylethylidene)indolin-2-one and 1,4-benzoxazinone/quinoxalinone derivatives promoted by tin(IV) chloride. The reaction is supposed to occur via a sequential intermolecular Michael addition of the 1,4-benzoxazinone derivatives to the oxindoles, intramolecular cyclization, and aromatization with the elimination of water. Apart from spectroscopic characterization, the structure of one of the pyrrolo[1,4]benzoxazinone derivative is confirmed by single-crystal X-ray diffraction. Thus, the developed domino protocol provides easy access to multifunctional pyrrolo[1,4]benzoxazines in one-pot with high efficiency.

Landfill leachate is highly polluted and generated as a result of water infiltration through solid waste produced domestically and industrially. This study investigated the applicability of the response surface methodology (RSM) to optimize the removal performances of chemical oxygen demand (COD), color, and suspended solids (SS) from landfill leachate by coagulation process using Tin tetrachloride pentahydrate. The leachate samples were collected from Alor Pongsu Landfill (APLS) in Perak, Malaysia. Before starting the experiments, general characterization was carried out for raw leachate samples to investigate their physical and chemical properties. The effects of the dosage and pH of SnCl4 on the removal performances were evaluated as well. An ideal experimental design was performed based on the central composite design (CCD) by RSM. In addition, this RSM was used to evaluate the effects of process variables and their interaction toward the attainment of their optimum conditions. The statistical design of the experiments and data analysis was resolved using the Design-Expert software. Further, the range of coagulant dosage and pH was selected based on a batch study which was conducted at 13000 mg/L to 17000 mg/L of SnCl4 and pH ranged from 6 to 10. The results showed that the optimum pH and dosage of SnCl4 were 7.17 and 15 g/L, respectively, where the maximum removal efficiency was 67.7% for COD and 100% for color and SS. The results were in agreement with the experimental data with a maximum removal efficiency of 67.84 %, 98.6 %, and 99.3%, for COD, color, and SS, respectively. Overall, this study verified that the RSM method was viable for optimizing the operational condition of the coagulation-flocculation process.

The authors are grateful to the Tunisian Ministry of High Education and Scientific Research and Technology for financial support of this research Bisphosphonates of the types X(P(O)(OEt)2)2 (X = CH2=C (1a), CNCH2CH (1b) and PhCH2NCH2CH (1c)) react with SnCl4 in anhydrous dichloromethane to produce the new tin(IV) adducts [SnCl4(1a)] (2a), [SnCl4(1b)] (2b) and [SnCl4(1c)] (2c) in 72-80% yields. These complexes were characterized using IR, multinuclear (1H, 13C, 31P, 119Sn) NMR spectroscopy, elemental analysis, and in one case by single crystal X-ray diffraction. The NMR data show that the bisphosphonate ligands are coordinated to the tin center in a bidentate fashion forming cis octahedral tin complexes. Furthermore, the X-ray structure of complex 2b reveals that the bisphosphonate ligand is coordinated in a bidentate manner to the metal center in a distorted octahedral arrangement with Sn-O-P bond angles in the range 135.95(16)–137.99(18)°. The P=O and Sn-O bond lengths of 1.495(3)-1.497(3) and 2.134(3)-2.146(2) Å, respectively are in the order expected for phosphonate tin(IV) complexes. The results are discussed and compared with closely related analogues. Postprint

A series of novel 1-(4-amino-6-methyl-1-aryl-1H-pyrazolo[3,4-b]pyridin-5-yl)-ethanones and 6-methyl-1-aryl-1H-pyrazolo[3,4-b]pyridin-4-amines were prepared by the annulation of 5-amino-1-aryl-1H-pyrazole-4-carbonitriles with acetylacetone in the presence of tin(IV) chloride. The results demonstrated that the ethanones are the precursors of second compounds.

Tin disulfide thin films were prepared with different molarities of tin species (MSn) at the optimized substrate temperature using the Nebulized Spray pyrolysis technique to obtain better crystallinity with mono phase thin films. The concentration of Tin IV chloride Penta hydrate precursor is varied from 0.05:0.4 to 0.25:0.4 (SnCl4.5H2O: thiourea) to achieve correct stoichiometry and to tune the concentration of Tin ions in the SnS2 thin films. These films were well adherent, uniform, and shiny. Lower concentrations of Tin yields highly textured SnS2 thin films with (001) crystallite orientation. On increasing the concentration, the multi-phases (SnS and Sn2S3) were found to be present along with SnS2 material. The platelet-like grains were observed from SEM analysis in these SnS2 films. Multiple interference effects were predominant in all these thin films in the wavelength region of 600–1100 nm. The direct optical band gap of tin disulfide thin films had decreased from 3.2 eV to 2.75 eV with an increase in MSn from 0.05 to 0.2 M, respectively, and further increased to 3.0 eV for 0.25 M concentration. Using Hall Effect measurement, the type of semiconductor is found to be of n-type. A minimum resistivity value of 2.19 × 103 Ω cm was obtained for the film grown at MSn = 0.2 M.

This paper investigates the third-order nonlinear optical properties of 4α-(4-tert-butylphenoxy) phthalocyaninato dichlorotin(IV) (α-SnOtBpPc) and 4β-(4-tert-butylphenoxy) phthalocyaninato dichlorotin(IV) (β-SnOtBpPc) in different organic solvents. The third-order susceptibilities of α-SnOtBpPc and β-SnOtBpPc are reported in different solvents, using Z-scan techniques with 10 ns laser pulses at 532 nm. Their nonlinear absorption coefficient and absorption cross sections were also determined. The molecular imaginary components of the second-order hyperpolarizability Im[γ] of α-SnOtBpPc and β-SnOtBpPc were found to be 2.60 × 10–31 and 2.94 × 10–31 esu (tetrahydrofuran), 2.12 × 10–31 and 2.54 × 10–31 esu (chloroform), 3.06 × 10–31 and 2.54 × 10–31 esu (dichloromethane), and 1.27 × 10–31 and 1.50 × 10–31 esu (toluene), respectively. This study found that substitution at the α position has an effect of lowering the two-photon (2PA) cross section value for α-SnOtBpPc compared to that for β-SnOtBpPc, with values...

Synopsis Total cross section for electron scattering from SnCl4 molecules has been measured for energies from 0.6 to 300 eV. Obtained results have been compared with total cross sections for electron scattering from other tetrachoride molecules: XCl4 where X=C, Si, Ge.

Benzyl esters are cleaved upon reaction with SnCl4, resulting in isolation of the corresponding carboxylic acid. Importantly, benzyl ethers, amines, and amides do not undergo debenzylation under these conditions, nor do a variety of other common protecting groups for alcohols, thereby rendering SnCl4 selective amongst Lewis acids. The scope, tolerance, and limitations of the strategy are demonstrated through the analysis of several multifunctional substrates, including those bearing Cbz groups.

The title compounds are partially condensed products of hydrolysed tri­methyl­tin chloride. In the two structures, short cationic tris­tannatoxanes (C9H29O2Sn3) are bridged by a diformatotri­methyl­tin anion or a chloride anion., The title compounds, [Sn3(CH3)9(OH)2(H2O)2][Sn(CH3)3(CHO2)2] (1) and [Sn3(CH3)9(OH)2]Cl·H2O (2), are partially condensed products of hydrolysed tri­methyl­tin chloride. In the structures of 1 and 2, short cationic tris­tannatoxanes (C9H29O2Sn3) are bridged by a diformatotri­methyl­tin anion or a chloride anion, respectively. Hydrogen bridges are present and supposedly stabilize these structures against further polymerization to the known polymeric tri­methyl­tin hydroxide. Especially noteworthy is that the formate present in this structure was formed from atmospheric CO2.

Thermal behavior of poly (methyl methacrylate) was analyzed in the presence of tin (IV) chloride. Five different proportionspolymer to additivewere selected for casting films from common solvent. TG, DTG and DTA were employed to monitor thermal degradation of the systems. IR and py-GC-MS helped identify the decomposition products. The blends start degrading at a temperature lower than that of the neat polymer and higher than that of the pure additive. Complex formation between tin of additive and carbonyl oxygen (pendent groups of MMA units) was noticed in the films soon after the mixing of the components in the blends. The samples were also heated at three different temperatures to determine the composition of residues left after the expulsion of volatiles. The polymer, blends and additive exhibited a one step, two-step and three-step degradation, respectively. T0 is highest for the polymer, lowest for the additive and is either 60 o C or 70 o C for the blends. The amount of residue increases down the series (moving from blend-1 (minimum additive concentration) to blend-5 (maximum additive concentration)). For blend-1, it is 7% of the original mass whereas it is 16% for blend-5. Tmax also goes up as the concentration of additive in the blends is elevated. The complexation appears to be the cause of observed stabilization. Some new products of degradation were noted apart from those reported earlier. These included methanol, isobutyric acid, acid chloride, etc. Molecular-level mixing of the constituents and "positioning effect" of the additive may have brought about the formation of new compounds. Routes are proposed for the appearance of these substances. Horizontal burning tests were also conducted on polymer and blends and the results are discussed. Activation energies and reaction orders were calculated. Activation energy is highest for the polymer, i.e., 138.9 Kcal/mol while the range for blends is from 51 to 39 Kcal/mol. Stability zones are highlighted for the blends. The interaction between the blended parts seems to be chemical in nature.

The title compound was crystallized according to the solid–liquid phase diagram at lower temperatures. It is built-up of SnCl4(H2O)2 octa­hedral units and lattice water mol­ecules. An intricate three-dimensional network of O—H⋯O and O—H⋯Cl hydrogen bonds between the complex molecules and the lattice water molecules is formed in the crystal structure., The title compound, [SnCl4(H2O)2]·6H2O, was crystallized according to the solid–liquid phase diagram at lower temperatures. It is built-up of SnCl4(H2O)2 octa­hedral units (point group symmetry 2) and lattice water mol­ecules. An intricate three-dimensional network of O—H⋯O and O—H⋯Cl hydrogen bonds between the complex molecules and the lattice water molecules is formed in the crystal structure.

Dimethyl(thioacetato)tin chloride (1) was synthesized by the reaction of dimethyltin dichloride with thioacetic acid in the presence of triethylamine. Compound 1 was subjected to hydrolysis under different reaction conditions in order to obtain sulfido/hydrosulfidotin compounds. Except for one case where the product was hexamethyl-1,3,5-trithia-2,4,6-tristannacyclohexane, (Me2SnS)3 (4), all other reactions led to desulfurization, and the products obtained were organostannoxane compounds, dinuclear tetramethyl-oxo-dichloroditin, {Me2SnCl2.Me2SnO} 2 (2), and tetraacetatodioxotetra( dimethyltin), (Me2Sn)4O2(O2CMe)4 (3). These complexes have been characterized by 1H, 13C, 119Sn NMR and FTIR spectroscopy, and compounds 2 - 4 also by X-ray crystallography. Density functional calculations were performed to explain the structure and reactivity of the compounds.

The three isostructural compounds butyl­ammonium hexa­chlorido­tin(IV), pentyl­ammonium hexa­chlorido­tin(IV) and hexyl­ammonium hexa­chlorido­tin(IV), (CnH2n+1NH3)2[SnCl6], with n = 4, 5 and 6, respectively, crystallize as inorganic–organic hybrids. As such, the structures consist of layers of [SnCl6]2− octa­hedra, separated by hydro­carbon layers of inter­digitated butyl­ammonium, pentyl­ammonium or hexyl­ammonium cations. Corrugated layers of cations alternate with tin(IV) chloride layers. The asymmetric unit in each compound consists of an anionic component comprising one Sn and two Cl atoms on a mirror plane, and two Cl atoms in general positions; the two cations lie on another mirror plane. Application of the mirror symmetry generates octa­hedral coordination around the Sn atom. All compounds exhibit bifurcated and simple hydrogen-bonding inter­actions between the ammonium groups and the Cl atoms, with little variation in the hydrogen-bonding geometries.

The compound bis(acetylacetonato)dichlorotin(IV) [Sn(acac)2Cl2] forms a distorted octahedral structure involving both oxygen atoms of the acetylacetone group. The two chlorides occupy the cis position, with Sn-Cl distances of Sn1-Cl1 = 2.380(2) A, Sn1-O1 = 2.043(2) A and Sn1-O2 = 2.093(2) A. We report here a new and simple method for the synthesis of Sn(acac)2Cl2, its spectroscopic characterization and, for the first time, we report its crystal structure.

The synthesis of the polysubstituted 8-oxa-1-azaphenalene lactone 4, which embodies the ABCring system of stephaoxocani dine, a tetracyclic isoquinoline alkaloid recently isolated from the tubers of Stephania cepharantha Hayata, is reported. Elaboration of 4 was carried out by means of the camphorsulfonic acid-assisted lactonization of 9, coupled to a titanium(IV) chloridemediated acetal cyclization of the resulting lactone 10 to form the tricyclic intermediate 12, followed by the base-promoted aromatization of the latter to 13 and final benzylic bromination. Lactone 4 constitutes an advanced key intermediate for the total synthesis of stephaoxocanidine, the simplest stephaoxocane.

Several new tetra-aryltin compounds, Ar4Sn (Ar = 3,5-(CH3)2C6H3, 3,5-Z2C6H3, and m-ZC6H4 (Z = F,Cl] and Ar3SnX [X = Cl, Br, I: Ar = 3,5-(CH3)2C6H3, m- and o-CH3OC6H4; X = Br; Ar = m-ZC6H4 (Z = F, Cl)] have been synthesized by literature methods and complete solution NMR data (119Sn, 13C) are reported for these and other meta- and ortho-substituted aryltins. Meta-substituents appear to exert electronic effects on chemical shifts and coupling constants, but for ortho-substituents steric effects appear to predominate. Crystal data show that meta-substituted Ar3SnX have trigonal unit cells in contrast to the monoclinic unit cells adapted by para- and ortho-substituted Ar3SnX. Complete crystal structures are reported for (m-CH3C6H4)3SnCl: R3. a = 14.9262(15), c = 7.3482(12) A , Z = 3 and (3,5-(CH3)2C6H3)3SnCl: R3c, a = 15.119(8), c = 15.593(4) A , Z = 6. In both cases, all molecules have trigonal symmetry, the first such examples to be reported.

The formal [3+2] cycloaddition of 5-methoxy-2-(p-methoxyphenyl)oxazole with 2(S)-(benzyloxy)-propanal and 2(S)- [(tert-butyldimethylsilyl)- oxy]propanal in the presence of tin(IV) chloride gave cis-(4R,5S,1'S)- and trans-(4S,5S,1'S)-5-(1'-alkoxyethyl)-4-(methoxycarbonyl)-2-(p-me- thoxyphenyl)-2-oxazolines with high diastereoselectivity (94 and 92% selectivity, respectively). A similar reaction of 5-methoxy-2-(p-metho- xyphenyl)oxazole with 2,3-di-O-benzyl-D-glyceraldehyde gave methyl cis- (4S,5R,1'R)-2-(p-methoxyphenyl)-5-[1',2'-bis(benzyloxy)ethyl]-2-oxazo- line-4-carboxylate with high diastereoselectivity (>95% selectivity), and the latter was easily converted to biologically important chiral 2-amino-1,3,4,5-tetrol derivatives

The synthesis of C7- to C16-alkyl maltosides in the presence of tin(IV) chloride as Lewis acid catalyst was performed. The characterization of the products and theoretical investigation of the crucial step in the synthesis were carried out. The preparation of the β-maltosides required reaction time of 1 h, and that of the α-maltosides was 72 h. The side products were the α-D-maltosidechloride and 2-hydroxy-β-maltoside, respectively. The PM3 calculation confirmed the formation of the kinetically controlled β-product. KEY WORDS : Maltose, Synthesis of maltosides, Tin(IV) chloride, PM3 Bull. Chem. Soc. Ethiop. 2011 , 25(1), 83-90.

In the title salt, [Sn(CH3)2Cl(CH4N3S)]Cl, the SnIV atom is five-coordinated in a distorted trigonal-bipyramidal geometry with two methyl groups and one S atom in the equatorial plane, and one N atom and one Cl atom occupying the apical positions. In the crystal, molecules are linked by intermolecular N—H...S hydrogen bonds with set graph-motif C(4) along [010]. N—H... Cl hydrogen bonds with graph-set motif D(2) and D33(10) link cations and anions.

Tin (IV) chloride reacts with sulfolane (S) to form a cis-octahedral adduct SnCl4·S2. Solutions of lithium chloride and tin (IV) chloride in sulfolane contain the complex ions SnCl5− and SnCl62− at 1∶1 and 2∶1 mole ratios of constituents, respectively. The complexes are characterized by conductimetry and by Mossbauer, IR, and Raman spectroscopy.

(+)-(1S, 5R, 7R)-5, 8, 8-Trimethylbicyclo [5. 1. 0] octan-3-one (2), which comprises the C/D-ring moiety of ingenol esters (1) and is an important chiral synthon for a total synthesis of ingenol esters from easily available (+)-3-carene (3), was synthesized. Intramolecular alkylation of 5b with a strong base under kinetic control gave only the undesired five-membered ketone (6). The intramolecular directed aldol reaction of a mixture of the silyl enol ethers, (9) and (10), easily derived from (+)-3 in good overall yield, was achieved in the presence of tin (IV) chloride to afford 11, 12, and 13 in 66, 9, and 6% yields, respectively. β-Elimination of the methoxy group of 11 gave an enone (14), which was methylated with lithium dimethylcuprate to afford the title compound (2) in good yield ; The configuration of the C-5 methyl group of 2 was deduced from the fact that catalytic hydrogenation of the enone (16), derived from 14 via 15, gave 2. Finally the stereochemistry of 2 was unambiguously determined by the chemical correlation of 18a, derived from 15, with 24b, derived from the known compound 19.

In condensation reactions of 2,3,5-tri-O-benzoyl-D-ribofuranosyl acetate with various kinds of enol silyl ethers in the presence of tin(IV) chloride, the acetate behaves as an ambident electrophile to give two types of products arising from nucleophilic attack of the enol ether on C-1 carbon of the ribose derivative and on carbonyl carbon of 2-benzoyloxyl group, depending remarkably on the enol silyl ethers.

In the coexistence of catalytic amounts of SnCl4 and ZnCl2, acetals undergo a coupling with 1-trimethylsilylalkynes to give secondary propargylic ethers in good yields. Similarly, propargylic ethers are directly produced from aldehydes by the treatment with alkoxytrimethylsilanes and 1-trimethylsilylalkynes under the same conditions. This catalyst system also efficiently promotes aldol reaction of silyl enol ethers with acetals or aldehydes, and the Michael reaction of silyl enol ethers with α,β-unsaturated ketones.

Several hydrates of tin(IV) chloride, e.g., SnCl4·xH2O (x=2, 3, 4 and 5) and SnCl4·yD2O (y=3, 4 and 5), were investigated by means of the nuclear quadrupole resonance (NQR) due to 35Cl and the Mossbauer effect due to 119Sn. The NQR-frequencies were observed at the temperature of liquid nitrogen and room temperature; they were found to range from 17.656 to 21.439 MHz. The Mossbauer effect was investigated only at the temperature of liquid nitrogen; it resulted in isomer shifts ranging from 0.275 to 0.350 mm/sec. The NQR-frequency and the isomer shift decreased with an increase in the number of water molecules in the hydrates, and the relationship between the NQR-frequency and the isomer shift was nearly linear. This relation was interpreted in terms of the transfer of the s-electrons of the tin atom to the chlorine atoms. Furthermore, it was revealed that there was a significant difference between the Sn-Cl bond of the hydrates and that of ammonium chlorostannate.

The Mossbauer spectra of molecular complexes of tin(IV) chloride with some oxygen-containing aromatic compounds, such as hydroxybenzaldehydes and cinnamic acid, were investigated. Most of these complexes show the quadrupole splitting resulting from the addition of aromatic molecules to tin(IV) chloride, although in some cases broad absorption curves are observed. The isomer shifts of these complexes are 0.25—0.45 mm/sec, much smaller than that of tin(IV) chloride itself. These values are almost the same as those of the complexes of tin(IV) chloride with aliphatic compounds. From these results, the bond nature and structures of these complexes, which had not previously been studied, were discussed in some detail.

In this work, a series of PhnSnCl4-n (n = 1, 2, 3, and 4) based catalysts were prepared by incipient wetness impregnation using activated carbon (AC) as support and triphenyltin chloride (Ph3ClSn) and tin(IV) chloride (SnCl4) as Sn precursors. The obtained catalysts were systematically characterized by X-ray diffraction (XRD), N2 physisorption, Scanning electron microscope (SEM), Thermogravimetric analysis (TG-DTG), and Inductively coupled plasma (ICP) analytical techniques. The catalytic performance of the prepared PhnSnCl4-n samples was evaluated in the acetylene hydrochlorination reaction. When a gas hourly space velocity (GHSV, C2H2 based) and a reaction temperature of 30 h-1 and 200 ºC, respectively were used for the reaction performed over the 12% (1.0Ph3ClSn+3.5SnCl4)/AC-200 catalyst, an acetylene conversion of 98.0% with a selectivity to vinyl chloride of 98.5% were obtained. These results demonstrated that PhnSnCl4-n can effectively improve the catalytic activity and prolong the lifetime of SnCl4/AC catalysts. Moreover, by comparing with HgCl2/AC, PhnSnCl4-n-based catalysts exhibit much enhanced catalytic activity in the hydrochlorination of acetylene. It is assumed that the outstanding activity is due to trichlorophenylstannane (PhCl3Sn) active sites, resulted from the organotin redistribution reaction between Ph3ClSn and SnCl4. In addition, such sites also improved the SnCl4/AC catalyst stability during the reaction.

C25H22ClNSn, monoclinic, P21/c (no. 14), a = 17.8179(8) Å, b = 15.6453(6) Å, c = 17.4603(7) Å, β = 116.588(2)°, V = 4352.6(3) Å3, Z = 8, R gt(F) = 0.0297, wR ref(F 2) = 0.0681, T = 100 K.