Syntheses and Characterization of 1D, 2D and 3D Organotin Polymers with Benzimidazole-5,6-dicarboxylic Acid and Trimethyltin Chloride

Three types of di- and trimethyltin(IV) polymers [Me₂Sn(C₉H₄N₂O₄)]_n · 4H₂O 1, [(Me₃Sn)₂(C₉H₄N₂O₄)]_n · H₂O 2 and [(Me₃Sn)₂(C₉H₄N₂O₄)]_n · CH₃OH 3 have been synthesized by the reaction of trimethyltin chloride with benzimidazole-5,6-dicarboxylic acid under three different experimental conditions. All the complexes were characterized by elemental analysis, IR, NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopy and X-ray crystallography diffraction analysis. The structure analyses reveal that complex 1 has a 1D helical chain in which benzimidazole-5,6-dicarboxylic acid act as a tetradentate (O,O-chelation) ligand coordinating to dimethyltin (IV) ions, two water molecules take part in the coordination giving seven-coordinated tin centers in the component. Complex 2 and 3 are 2D and 3D corrugated polymers in which the deprotoned acid as tetradentate ligand affords by three oxygen atoms and a nitrogen atom.     

Synthesis of a new 2D fluorogallophosphate intercalated by double organic sheets of morpholine

One way to obtain new materials is to exploit the in situ generation of the structure-directing agent. By this synthetic route, solvents or precursors of the templates are introduced into the starting mixtures, and during the synthesis, they partly decompose into molecules that act as templates. This paper deals with the synthesis of a fluorogallophosphate with a new template precursor, the N-formylmorpholine. This compound, used as main solvent, is unstable in acidic media. At high temperature it decomposes and generates in situ the morpholine molecules. We report the structure of a two-dimensional fluorogallophosphate named Mu-38 structurally related to ULM-9. This compound Ga₃P₃O₁₂F₃[C₄H₁₀NO]₃ (Z = 4) consists of anionic inorganic layers containing single four rings units linked and charge-balanced by protonated morpholine. It was also characterized by powder XRD, SEM, elemental and thermal analyses, and solid state NMR spectroscopy (¹³C, ¹⁹F and ³¹P MAS and ³¹P CP MAS experiments).     

Novel Supramolecular Square Grid-Like Structure: Synthesis and Characterization of [(Me3Sn)2CrO4]

Reactions of K₂Cr₂O₇ and K₂CrO₄ with Me₃SnCl yielded [(Me₃Sn)₂CrO₄] (1) and [(Me₃Sn)₂CrO₄(Me₃SnOH)] (2), respectively, which were characterized by elemental analysis, ¹H-NMR spectroscopy, and an X-ray diffraction study. Compound 1 shows a novel square grid-like structure consisting of CrO₄ ^2– and Me₃Sn⁺ ions, whereas 2 exhibits a three-dimensional structure composed of CrO₄ ^2–, Me₃Sn⁺, and [(Me₃Sn)₂SnOH]⁺ ions.     

Syntheses and Characterization of 2D and 3D Organotin Polymers with Phenylsuccinic Acid and Trimethyltin Chloride Under Different Conditions

Two types of di- and trimethyltin(IV) polymers [(Me₂Sn)₄O₂(C₁₀H₈O₄)₄] _n 1 and [(Me₃Sn)₂(C₁₀H₈O₄)] _n ·DMF 2 have been synthesized by the reaction of trimethyltin chloride with (±)-phenylsuccinic acid under two different experimental conditions. Both of the complexes are characterized by elemental analysis, IR, NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopy and X-ray crystallographic diffraction analysis. The structural analyses show that complex 1 is a two-dimensional corrugated sheet polymer consisting of dimeric tetraorganodistannoxane units and bridging ligands. Complex 2 is a 3D corrugated polymer in which the deprotoned acid occurs as a tetradentate ligand and is bonded by the four oxygen atoms. It is worth noting that the X-ray diffraction study reveals that complex 2 crystallizes in the orthorhombic space group P212121, which is chiral space group.     

On the Effect of Hydrocarbon/Oxygen Ratios During the Dehydrogenation of <Emphasis Type="Italic">n</Emphasis>-Octane Over a VMgO Catalyst

Abstract  

A vanadium–magnesium oxide catalyst (VMgO) with a V₂O₅ concentration of 15% by weight was employed for the oxidative dehydrogenation of n-octane to produce the corresponding linear octenes and C8 aromatics. The catalyst was synthesized by the wet impregnation method, and was characterized by in situ XRD, TGA-DSC, and ⁵¹V MAS NMR. The used catalysts were characterized by powder XRD, BET, pore volume analysis, SEM, EDX, ICP-OES, and ¹⁵V MAS NMR. The catalytic testing was carried out at different n-octane/O₂ molar ratios (viz. 0.1, 0.4, 0.8, 1.2, and 1.6) at a GHSV of 8,000 h⁻¹ in a continuous flow fixed bed reactor. The results showed that the catalytic performance with regard to both activity and selectivity was very sensitive to the strength of the oxidative environment (n-octane to oxygen ratio). No phasic changes were observed in the used catalysts. However, some textural changes were induced by the catalytic testing.     

Syntheses and Crystal Structures of Di- and Trimethyltin Carboxylates: Ladders and 1D Zig–Zag Chains Polymers

A series of organotin(IV) carboxylates complexes; namely, [(Me₂Sn)₄O₂(RCOO)₄] (R = C₁₂H₁₅ 1, C₉H₁₁ 2, C₈H₈ClO 3, C₇H₉ 4) and [Me₃(RCOO)]_n (R = C₁₂H₁₅ 5, C₉H₁₁ 6, C₈H₈ClO 7, C₇H₉ 8) have been synthesized. All complexes were characterized by elemental analysis, FT-IR, and NMR (¹H, ¹³C and ¹¹⁹Sn) spectroscopy. Among them, the structures of complexes 1–3 and 5–8 were also determined by X-ray crystallography. The structural analysis showed that complexes 1–3 are the same tetranuclear monomer, and complexes 5–8 are the same 1D zigzag chain coordination polymer. Furthermore, each complex 1, 2 and 3, can form a supramolecular chain through weak intermolecular interactions.     

Characterization of a chiral menthyldimethyltin molybdate and its use as an olefin epoxidation catalyst

Vibrational spectroscopy and EXAFS studies of an organotin molybdate with the formula [((Me)₂(menthyl)Sn)₂MoO₄(H₂O)_3.5] reveal that the compound is polymeric and contains [MoO₄]²⁻ tetrahedra coordinated to [R₃Sn]⁺ cationic spacers. The compound can be used as a recyclable solid catalyst for the selective epoxidation of cyclooctene by tert-butylhydroperoxide. In the epoxidation of prochiral olefins such as trans-β-methylstyrene, the corresponding epoxide isomers are obtained with fairly good to excellent selectivity, albeit with low enantiomeric or diastereomeric excesses.     

Solvothermal Synthesis and Crystal Structure of a Novel 3D Triorganotin Polymer Containing Polyfunctional Ligand 5-mercapto-1(H)-tetrazoleacetic acid

A novel 3D tri-n-butyltin complex [(n-Bu₃Sn)₂(C₂H₂N₄SCO₂)]_n (1) has been solvothermally synthesized and structurally characterized by elemental analysis, FT-IR, NMR (¹H, ¹³C, and ¹¹⁹Sn) spectra and X-ray crystallography. X-ray data of complex 1 reveals that it is a 3D tri-n-butyltin coordination polymer with a metal-organic framework (MOF) structure , significant N → Sn interactions plays an important role in the construction of this structure.     

Synthesis,Characterization and Crystal Structure of New Organotin Copper Cyanide Three-Dimensional Supramolecular Coordination Polymer Containing Quinoxaline Molecule

Self assembly of K₃[Cu(CN)₄] with Me₃SnCl and quinoxaline (qox) affords the new organotin ternary adduct _∞³[Cu₂(CN)₃·Me₃Sn·qox], 1, as orange platelet crystals. The supramolecular architecture of 1 consists of [Cu₂(CN)₃]⁻ building blocks connected by the (Me₃Sn)⁺ cations forming infinite corrugated 1D-chains. The chains are bridged by the qox molecules forming 2D-layers containing fused distorted polygons. The layers are interwoven forming 3D-network structure, which are stabilized by close packing effects such as H-bonds as well as Cu···Cu and π–π interactions. IR and mass spectra as well as TGA are investigated.     

Grafting of Molecularly Ordered Mesoporous Phenylene‐Silica with Molybdenum Carbonyl Complexes: Efficient Heterogeneous Catalysts for the Epoxidation of Olefins

Arenetricarbonyl complexes, or the general formula  C₆H₄Mo(CO)₃ , were incorporated into crystal‐like mesoporous phenylene‐silica by liquid‐phase deposition of molybdenum hexacarbonyl [Mo(CO)₆]. By adjusting the reaction conditions, different molybdenum loadings of 1.5 and 5.9 wt% were obtained, which correspond to 3% and 14% of the phenylene contents. The texture properties of the materials as well as the nature of the surface‐fixed complexes were characterized by powder X‐ray diffraction, transmission electron microscopy (TEM), N₂ adsorption, FT‐IR, UV‐vis and MAS (¹³C, ²⁹Si) NMR spectroscopy. The derivatized organosilicas were examined as catalyst precursors for the liquid‐phase epoxidation of cis‐cyclooctene, 1‐octene, trans‐2‐octene and (R)‐(+)‐limonene at 55 °C, using tert‐butyl hydroperoxide as the oxidant. For each olefin the corresponding epoxide was the only product detected. In the case of cyclooctene, the intrinsic reaction rates per surface molybdenum atom were similar for both Mo loadings (TOF∼1150 mol mol_Mo⁻¹ h⁻¹), suggesting that the resultant materials act as single site epoxidation catalysts. Leaching tests and metal analyses of reaction solutions showed that the catalytic activity stemmed from the immobilized species and not from the leaching of active species into solution. The oxidation of limonene gave limonene oxide as the only product in 95% yield at 3 h, which reveals an outstanding regioselectivity to the epoxidation of the endocyclic double bond.     

Synthesis, Characterization and Crystal Structure of a Novel One-Dimensional Supramolecular Dimethyltin (IV) Compound

A novel one-dimensional (1D) supramolecular dimethyltin compound of (Me₂SnO)₂(Me₂SnOCH₃)(O₂CCH₂SC₄H₃N₂-2,6)[Me₂Sn(O₂CCH₂SC₄H₃N₂-2,6)₂]·CH₃OH was prepared by the reaction of (CH₃)₂SnCl₂ with (2-pyrimidylthio)acetic acid with CH₃ONa as a base. The title compound contained four different tin atom environments. Among them, Sn(1) and Sn(2) were both five-coordinate with distorted trigonal bipyramidal geometries, Sn(3) was six-coordinate with a distorted octahedral geometry and Sn(4) was seven-coordinate with pentagonal bipyramidal geometry. Meanwhile, the compound was stabilized in a 1D infinite chain by intermolecular Sn–O bonds. An erratum to this article can be found at     

Synthesis and NMR studies of the polymer membranes based on poly(4-vinylbenzylboronic acid) and phosphoric acid

Proton conduction in novel anhydrous membranes based on host polymer, poly(4-vinylbenzylboronic acid), (P4VBBA) and phosphoric acid, (H₃PO₄) as proton solvent was studied. The materials were prepared by the insertion of the proton solvent into P4VBBA at different stoichiometric ratios to get P4VBBA·xH₃PO₄ composite electrolytes. Homopolymer and the composite materials were characterized by FT-IR, ¹¹B MAS NMR and ³¹P MAS NMR. ¹¹B MAS NMR results suggested that acid doping favors or leads to a four-coordinated boron arrangement. ³¹P MAS NMR results illustrated the immobilization of phosphoric acid to the polymer through condensation with boron functional groups (B-O-P and/or B-O-P-O-B). Thermogravimetric analysis (TGA) showed that the condensation of composite materials starts approximately at 140 °C. An exponential weight loss above this temperature was attributed to intermolecular condensation of acidic units forming cross-linked polymer. The insertion of phosphoric acid into the matrix softened the materials shifting T_g to lower temperatures. The temperature dependence of the proton conductivity was modeled with Arrhenius relation. P4VBBA·2H₃PO₄ has a maximum proton conductivity of 0.0013 S/cm at RT and 0.005 S/cm at 80 °C.     

Thermal and NMR Studies of Polystyrene Blends

Abstract

The effect of addition of poly (propylene oxide) (PPO) and polystyrene with low molecular weight (LPS) to polystyrene (PS) was investigated blending these polymers in a Haake internal mixer. The PPO and LPS range was established up to 10% by weight. The blends were analysed by differential scanning calorimetry (DSC) and carbon-13 nuclear magnetic resonance spectroscopy at solid state (NMR), using conventional NMR techniques as cross-polarisation/magic angle spinning (CP/MAS) and proton spin-lattice relaxation time in the rotating frame (T ₁ ^H _p ). The addition of 1 and 5% of PPO and 5% of LPS to PS made the blends of PS/PPO and PS/LPS more rigid.     

Preparation of Zinc(II) Oxide Nanoparticles from a New Nano-Size Coordination Polymer Constructed from a Polypyridyl Amidic Ligand; Spectroscopic, Photoluminescence and Thermal Analysis Studies

A new zinc(II) coordination polymer, {[Zn(bpcdp)₂(DMF)₄](ClO₄)₂·(H₂O)₂}_n (1) bpcdp = 2,6-bis(4-pyridinecarboxamide)pyridine has been synthesized and characterized by IR, ¹HNMR and ¹³CNMR spectroscopy. The single crystal X-ray data of compound 1 shows the zinc(II) atom has been considered as octahedral with ZnN₂O₄ coordination sphere. Two nitrogen atoms of bpcdp ligand and four oxygen atoms of DMF molecules have occupied coordination sphere around zinc(II) atoms. The prepared zinc(II) coordination polymer grows in three-dimensional network by hydrogen bonding and π–π stacking interaction. The nanostructure of compound 1 were obtained by sonochemical process and studied by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), IR and NMR spectroscopy. Thermal stabilities of single crystalline and nano-size samples of compound 1 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The ZnO nanoparticles were obtained by direct calcination of compound 1 at 400 °C and by thermolysis in oleic acid at 200 °C. The obtained zinc(II) oxide nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).     

Syntheses, Characterization and Crystal Structures of 1D and 2D Organotin Polymers Containing 3-Methyladipic Acid Ligand

Four new organotin (IV) complexes of two types [(R₂Sn)₂(C₇H₁₀O₄)(μ₃-O)] _n (R = Me: 1; nBu: 2; and {(R₃Sn)₂[C₅H₁₀(COO)₂]} _n (R = Me: 3; nBu: 4) have been synthesized by the reaction of 3-methyladipic acid with the corresponding R₃SnCl (R = Me, nBu) under two different experimental conditions. All the complexes were characterized by elemental analysis, FT-IR, and NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopy. Except for 2, all of the complexes were also characterized by X-ray crystallography. The structural analyzes show that complex 1 is a 1D infinite chain polymer and forms a 2D organotin framework through intermolecular C–H···O interactions and weak Sn···O interactions. Complexes 3 and 4 are 2D network polymers in which 3-methyladipic acid acts as a tetra dentate ligand coordinated to the trialkyltin (IV) ion.     

31P and119Sn high resolution solid state CP/MAS NMR study of Al2O3-SnO2 systems

A series of Al₂O₃-SnO₂ catalysts with the mole ratio of Al₂O₃ to SnO₂ equal to 1:1, 1 0.5, 1 0.1, 1 0.05 and 1 0.01 were characterized by³¹P NMR of adsorbed trimethyl phosphine (TMP) and¹¹⁹Sn MAS NMR spectroscopy. It was found from³¹P NMR that no Brønsted acid sites exist in these samples. Pure SnO₂ shows two different types of Lewis acid sites; in the mixed oxide samples a Lewis peak characteristic of pure Al₂O₃ is always seen, together with either one or two other Lewis peaks, depending on the Sn concentration.¹¹⁹Sn CP/MAS NMR spectra of the highest Sn-content sample show one narrow line at –603 ppm superimposed on a very broad line, indicating a strong interaction between Al and Sn oxides.     

Investigation on the Reaction of Powdered Tin as a Metallic Fuel with Some Pyrotechnic Oxidizers

Thermogravimetry (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) have been used to examine the thermal behavior of Sn+KClO₃, Sn+KNO₃, and Sn+KClO₄ pyrotechnic systems and the results were compared with thermal characteristics of individual constituents. TG curves for tin powder, heated alone in air, showed a relatively slow oxidation above 570 °C. From thermal results the decomposition temperatures of KClO₃, KClO₄, and KNO₃, in nitrogen atmosphere, were measured at 472, 592 and 700 °C, respectively. For the Sn+KNO₃ pyrotechnic system, the tin oxidation was completed within the range of 480 to 500 °C. Replacing KNO₃ with KClO₄ led to an increase of thermal stability of the pyrotechnic mixture. Among above‐mentioned pyrotechnic mixtures, Sn+KClO₃ has the lowest ignition temperature at about 390 °C. The apparent activation energy (E), ΔG^#, ΔH^# and ΔS^# of the combustion processes were obtained from the DSC experiments. Based on these kinetic data and ignition temperatures, the relative reactivity of these mixtures was found to obey in the following order: Sn+KClO₃>Sn+KNO₃>Sn+KClO₄.     

Synthesis of Diorganotin Esters of 5-Bromonicotinic Acid: X-ray Crystal Structure of Polymeric 5-Bromonicotinatodiorganotin

Two types of diorganotins [R₂Sn(OCOC₅H₃N-3-Br-5)₂] _n and {[R₂Sn(OH₂)(OCOC₅H₃N-3-Br-5)₂]₂} _n (R= Me, n-Bu, Ph, n-Oc), are prepared from 5-Br-omonicotinic acid and diorganotin oxides. All the compounds, 1–8, are characterized by elemental analysis as well as IR and ¹H-NMR spectroscopy. The crystal structures of [R₂Sn(OCOC₅H₃N-3-Br-5)₂] _n (2) and {[R₂Sn(OH₂)(OCOC₅H₃N-3-Br-5)₂]₂} _n (8) were determined by single crystal X-ray diffraction. In compound 2, each carboxylate moiety of 5-Br-omonicotinic acid is involved in coordination to one Sn atom via two O-atoms, and the N-atom of one pyridine-ring coordinates to the neighboring Sn atom which leads to a polymeric chain. And the N-atom of the other pyridine-ring is dissociative. In compound 8, the compound proves to be dinuclear macrocyclic compounds with 5-Br-omonicotinic acid bridging the adjacent tin atoms with a 12-member ring. The hydrogen bonds ( ) are observed in the compound 8. These intermolecular hydrogen bonds form another ring, and lead to a polymeric chain in the lattice at the same time. An erratum to this article can be found at     

Parameters of the epoxidation of 1-octene by t-butyl hydroperoxide

The epoxidation of 1-octene with t-butyl hydroperoxide in the presence of Mo(CO)₆ has been studied. The influence of the crucial parameters on the yield of 1,2-epoxyoctane in relation to hydroperoxide, on the hydroperoxide conversion, on the selectivity of the transformation of 1-octene to epoxy compound and on the yield of 1,2-epoxyoctane in relation to 1-octene has been described by the use of regression functions in the form of a second order polynomial. The optimal values of parameters: reaction time, temperature, olefin to hydroperoxide mol ratio, Mo(CO)₆ to hydroperoxide mol ratio, ensuring the maximum values of these functions have been determined.     

π‐Complexation Studied by Fluorescence Technique: Application in Desulfurization of Petroleum Product using Magnetic π‐Complexation Sorbents

Abstract

Magnetic π‐complexation sorbents were studied for petroleum product desulfurization by fluorescent technique. The ability of metal cation to form π‐complexation decreases in the order following: Cu⁺>Ni²⁺>Co²⁺>Al³⁺. The order is consistent with that of desulfurization performance of their corresponding magnetic sorbents (γ‐Al₂O₃‐Cu(I)>γ‐Al₂O₃‐Ni(II)>γ‐Al₂O₃‐Co(II)>γ‐Al₂O₃). Both π‐complexation strength and desulfurization performance of the sorbents increase with temperature. The adsorptive performances of magnetic γ‐Al₂O₃‐Cu(I) sorbent to different compounds have the following orders: DBT>fluorene, and pyrene>naphthalene>benzene, respectively. In this study, dibenzothiophene (DBT) was used as a model sulphur‐containing compound for desulfurization. The maximal adsorption amount of magnetic γ‐Al₂O₃‐Cu(I), was 0.362 mmol DBT g^?1.