AlCl3 · 2NH3 – eine Verbindung mit der Kristallstruktur eines Tetraammindichloroaluminium-tetrachloroaluminats – [AlCl2(NH3)4]+[AlCl4]−

ACl₃ · 2NH₃ – a Compound with the Crystal Structure of a Tetraammine Dichloroaluminiumtetrachloroaluminate – [AlCl₂(NH₃)₄]⁺[AlCl₄]^? Ammoniates of aluminiumchloride AlCl₃ · xNH₃ are in discussion as starting materials for the synthesis of aluminiumnitride. Therefore the reactions of melts of monoamminealuminiumchloride with ammonia were investigated. They react at 150°C within 10 min with one mole of ammonia to the diammoniate, [AlCl₂(NH₃)₄]⁺[AlCl₄]^?. The pure compound can be obtained by sublimation at 200°C in vacuumline apparatus. X-ray structure determination on [AlCl₂(NH₃)₄]⁺[AlCl₄]^? was carried out: see “Inhaltsübersicht”.     

Synthesis and properties of novel σ–π alternating polymers with triphenylamine and organosilicon units

We have synthesized novel σ–π conjugated polymers with N,N‐bis(p‐ethynylphenyl)‐N‐(p‐tolyl)amine as the π‐unit. The electroluminescent devices, with a double‐layer system composed of Alq and the present polymers as the emitting‐electron‐transporting and hole‐transporting layers respectively, emit green electroluminescence with a maximum intensity of 760 cd m^?2. Copyright © 2001 John Wiley & Sons, Ltd.     

Synthesis and properties of σ–π conjugated alternating polymers consisting of carbazole and organosilicon units

We have synthesized novel σ–π conjugated polymers with an alternating organosilanylene and π‐electron system, intending to utilize them for hole‐transporting materials of electroluminescent (EL) devices. 3,6‐Di(lithioethynyl)carbazoles were co‐polymerized with organodichlorosilanes to give the corresponding polymers with molecular weights of M_W = 2000–5000. Another type of polymer with a thienylene unit was also synthesized by the nickel‐catalyzed reaction of the di‐Grignard reagent of 1,2‐bis[2‐(5‐bromothienyl)]tetraethyldisilane with 3,6‐dibromocarbazole, the molecular weight being M_n = 3100. The EL devices with a double‐layer system composed of tris(8‐quinolinolato)aluminum(III) and the present polymers as the emitting‐electron‐transporting and hole‐transporting layers, respectively, emit green EL with a maximum intensity of the order of 10³ cd m^?2. Of these, the device with the thienylene–carbazole polymers exhibited the highest luminance of 1480 cd m^?2. Copyright © 2001 John Wiley & Sons, Ltd.     

Synthesis and characterization of γ–alumina nanospheres templated by lauric acid

A novel route for the synthesis of alumina nanospheres was reported by a surfactant-governed approach in the presence of lauric acid. The products were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM) and N2 adsorption-desorption techniques. The results show that the produced alumina nanospheres possess uniform nanosphere sizes ranging from 80-120 nm, and high surface area of 550 m²/g. It suggests that the synthesized alumina nanospheres are formed through self-assembly of surfactant/alumina species complex in 1-propanol system.     

Photophysical properties of σ–π‐conjugated alternating oligothienylene–oligosilylene polymers

UV‐visible absorption and fluorescence properties of three series of σ–π‐conjugated polymers (copolymers of alternative oligothienylene and oligosilylene units) have been studied in dioxane solution. The energies of the absorption maximum, fluorescence maximum, and the 0–0 transition are found to be linearly dependent on the reciprocal of the number of thiophene rings in the repeating unit of the polymer chain, but almost independent of the silicon atom number. The σ–π‐conjugation in the polymers results in red shift in the absorption and fluorescence maxima, higher fluorescence quantum yields, and longer fluorescence lifetimes of the polymers, with respect to their corresponding analogous α‐oligothiophenes. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1873–1880, 1999     

Acid–base complexes of polymers

The physical interactions of polymers with neighboring molecules are determined by only two kinds of interactions: London dispersion forces and Lewis acid–base interactions. These two kinds of attractive energies (together with certain steric restrictions) determine solubility, solvent retention, plasticizer action, wettability, adsorption, adhesion, reinforcement, crystallinity, and mechanical properties. The London dispersion force interaction energies of polymers have been quantified by the dispersion force contribution to cohesive energy density (δ²_d) and the dispersion force contribution to surface energy (δ^d). The Lewis acid–base interactions, often referred to as “polar” interactions, can be best quantified by Drago's C_A and E_A constants for acid sites and C_B and E_B constants for basic sites. In this article infrared spectral shifts are featured as a method of determining enthalpies of acid–base interaction, and the C and E constants for polymers, plasticizers, and solvents. Examples are given where acid–base complexation of polymers with solvents dominate solubility and swelling phenomena. Enthalpies of acid–base complexation in polymer blends are determined from spectral shifts.     

Crosslinking of polystyrene under friedel–crafts conditions in dichloroethane and carbon tetrachloride solvents through the formation of strongly colored polymer–AlCl3–solvent complexes

Polystyrene was crosslinked in either 1,2-dichloroethane or carbon tetrachloride in the presence of aluminum chloride. Apparently, the reactions involve Friedel–Crafts substitution of phenyl ring with CH₂CH₂Cl or CCl₃ groups, which than participate in crosslinking, giving CH₂CH₂ or CCl₂, CCl, and C bridges. In the first stage a charge-transfer complex is formed between AlCl₃, polystyrene and the solvent. After heating this complex above 35–40°C a rapid formation of HCl occurs and a crosslinked polymer is formed. This final product is insoluble, infusible, and inflammable. It decomposes at 400°C without melting.     

Covalently linked ethylmercaptophenyl sulfonic acid and ethylmercaptobenzyl sulfonic acid silica materials—Synthesis and catalytic activity

New covalently linked sulfonic acid modified silicas have been formed and characterised and their catalytic Brönsted activity evaluated. Thus phenylmercaptoethyltrimethoxysilane, (MeO)₃SiCH₂CH₂SC₆H₅ and benzylmercaptoethyltrimethoxysilane, (MeO)₃SiCH₂CH₂SCH₂C₆H₅, were used to prepare the corresponding T-functional silica derivatives silica  CH₂CH₂SC₆H₄-4-SO₃H and silica  CH₂CH₂SCH₂C₆H₄-4-SO₃H by grafting on commercial silica, followed by sulfonation of the aryl group. Solid-state NMR, DTA and surface area characteristics of the materials are reported. The mercaptophenylsulfonic acid materials are thermally robust highly efficient solid catalysts for a range of transformations including, esterification, etherification and carbonyl group protection. An apparent pore size effect on rate of conversion was observed. The mercaptobenzylsulfonic acid materials were comparatively unstable.     

Synthesis,characterization and application of sulfonic acid supported on ferrite–silica superparamagnetic nanoparticles

In this study, the synthesis of sulfonic acid supported on ferrite–silica superparamagnetic nanoparticles (Fe₃O₄@SiO₂@SO₃H) as a nanocatalyst with large density of acidic groups is suggested. This nanocatalyst was prepared in three steps: preparation of colloidal iron oxide magnetic nanoparticles (Fe₃O₄ MNPs), coating of silica on Fe₃O₄ MNPs (Fe₃O₄@SiO₂) and incorporation of sulfonic acid as a functional group on the surface of Fe₃O₄@SiO₂ nanoparticles (Fe₃O₄@SiO₂@SO₃H). The properties of the prepared magnetic nanoparticles were characterized using transmission electron microscopy, infrared spectroscopy, vibrating sample magnetometry, X‐ray diffraction and thermogravimetric analysis. Finally, the applicability of the synthesized magnetic nanoparticles was tested as a heterogeneous solid acid nanocatalyst for one‐pot synthesis of diindolyloxindole derivatives in aqueous medium. Oxindole derivatives were produced by the coupling of indole and isatin compounds with good to high yields (60–98%). Copyright © 2016 John Wiley & Sons, Ltd.     

Block polymers from isocyanate-terminated intermediates. II. Preparation of butadiene–ϵ-caprolactam and styrene–ϵ-caprolactam block polymers

Polystyrene–nylon 6 and polybutadiene–nylon 6 block copolymers have been prepared from isocyanate-terminated prepolymers. From extraction and fractionation data the products obtained were found to be mixtures of both homopolymers and pure block copolymer. The polybutadiene–nylon 6 copolymers are extremely pliable at ambient temperatures even at high ?-caprolactam contents (70–80 wt-%). This is true even though these copolymers show a crystalline melting point at 213°C similar to poly-?-caprolactam. Presumably this unusual behavior occurs because of the nature of the synthesis which renders the butadiene portion of these copolymers the continuous phase. Plasticity measurements indicate that pliability is dependent on the molecular weight of the block poly-?-caprolactam.     

Synthesis and optical properties of σ–π conjugated organic–inorganic hybrid gels

Organic–inorganic hybrid gels containing Si‐vinylene units have been synthesized by a hydrosilylation reaction of tri‐ or tetra‐ethynyl aryl compounds, 1,3,5‐triethynylbenzene (TEB), 3,3′,5,5′‐tetraethynylbiphenyl (TEBP), or tetrakis(4‐ethynylphenyl)methane (TEPM), and bisdimethylsilyl compounds, 1,1,3,3‐tetramethyldisiloxane (TMDS) or 1,4‐bisdimetylsilylbenzene (BDMSB), in toluene. Network structure of the resulting gels was quantitatively characterized by a scanning microscopic light scattering. The reactions yielded the gels having homogeneous network structure of 1.5–2.9 nm mesh size under the monomer concentrations that were relatively higher than the critical gelation concentration. The gels obtained from TEB showed broad absorption in the range from 340 to 370 nm, and emission in the range from 440 to 490 nm. The TEB–BDMSB gels showed remarkable red shift of the emission in comparison with that of the corresponding reaction solutions derived from the network formed by σ–π conjugation. The TEPM–TMDS, BDMSB gels exited by 280 nm showed not only the emission peak at around 360 nm derived from TEPM, but the broad peak at around 420 nm, which should be derived from interaction between phenyl groups of TEPM in the gels. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1360–1368     

Synthesis and properties of through‐space conjugated polymers based on π–π stacked 1,3‐biarylpropane tethering units

Novel skipped‐π polymers in which the π‐components are connected with 2‐substituted trimethylene tethering units exhibit bathochromically shifted, broadened ultraviolet absorption with a unique lower‐energy absorption band and a largely red‐shifted fluorescent emission. These results suggest that through‐space π–π interactions owing to a stair‐like stacking substructure in these polymers extend the π‐conjugation of the components in the ground and excited states. As the photophysical properties of the polymers observed both in a solution and in a dried film are similar to those of the J‐aggregates of π‐molecules, these polymers may be considered as pseudo J‐stacking (or J‐like‐stacking) polymers. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3412–3419     

Poly(galacturonic acid)–bivalent metal complexes

Complexation or stability constants have been determined for complexes of poly-(galacturonic acid) with Cu, Cd, Zn, and Ni. The stability of complexation decreases as follows: Cu > Cd > Zn > Ni.     

Regio‐ and Stereoselective Reaction of α‐Epoxyketones with AlCl3: An Efficient Approach for the Synthesis of Functionalized β‐Chlorohydrines

A simple and efficient synthesis of functionalized β‐chlorohydrins is described from the regio‐ and stereoselective reaction of α‐epoxyketones with AlCl₃ in acetonitrile at room temperature.     

AlCl3 · 3NH3 — eine Verbindung mit der Kristallstruktur eines Tetraammindichloroaluminium-diammintetrachloroaluminats: [AlCl2(NH3)4]+[AlCl4(NH3)2]−

AlCl₃ · 3NH₃ — a Compound with the Crystal Structure of a Tetraammine Dichloro Aluminium-Diammine Tetrachloro Aluminate: [AlCl₂(NH₃)₄]⁺[AlCl₄(NH₃)₂]^? . AlCl₃ · 3 NH₃ ? [AlCl₂(NH₃)₄]⁺ [AlCl₄(NH₃)₂]^? forms during the reaction of two mole NH₃ with AlCl₃(NH₃) at T ≥ 200°C. Repeated heating and cooling within 48 h between 200°C and 250°C gives a homogeneous product with total uptake of the necessary amount of NH₃. Slow sublimation in a vacuum line apparatus at 200°C gives crystals of the triammoniate sufficient for a X-ray structure determination: The compound contains elongated [AlCl₂(NH₃)₄]⁺ octahedra and compressed [AlCl₄(NH₃)₂]^? octahedra. Besides ionic bonding hydrogen bridge bonds with 3.369 Å ? d(N—H … Cl) ? 3.589 Å stabilize the atomic arrangement.     

Control of regioselectivity by cation-exchanged sulfonic acid resin catalysts

In t-butylation of hydroquinones and condensation of methyl N-phenyl carbamate, cation-exchanged sulfonic acid resin catalysts exhibited significantly better regioselectivity than liquid mineral acid catalysts. This trend was independent of the acid strength of the catalysts and the reaction conditions employed, including choice of solvent. The magnitude of the effect, however, depended on the bulkiness of the substituents. The difference between these heterogeneous and homogeneous acid catalysts was attributed to steric hindrance imposed on fixed protons in the solid catalysts, which caused higher selectivity toward the less-hindered position.     

Synthesis of phenanthroline‐terminated polymers and their Fe(II)‐complexes

Well‐defined mono‐ and bifunctional, phenanthroline‐terminated poly(ethylene glycol) and polyisobutylene capable of polymer network formation were synthesized. The starting materials mono‐ and bi‐phenanthroline‐ (phen) terminated poly(ethylene glycols) (mPEG‐phen, phen‐PEG‐phen) and polyisobutylenes (PIB‐phen, phen‐PIB‐phen) were prepared by the Williamson synthesis and characterized by means of ¹H NMR and MALDI‐TOF mass spectrometry. According to UV–Vis spectrophotometry and ESI‐TOF mass spectrometry, the phenanthroline‐terminated polymers underwent quantitative complex formation with ferrous ions in solution. The aqueous solution of mPEG‐phen shows self‐assembly behavior. Important parameters, such as critical micelle concentration and hydrodynamic radius of the aggregates were also determined. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2709–2715, 2010     

Soluble conducting polymers: The poly(3–alkylthienylene)s

The conjugated poly(3-alkylthienylene)s, P3ATs, can be processed from solution and subsequently used as semiconducting and metallic polymers. Both as-synthesized and solution-cast films can be readily doped with resulting electrical conductivities which are quite high, σ-30–100 S/cm.     

Synthesis and characterization of aromatic polymers derived from 5‐perfluoroalkylisophthalic acid

A series of polyisophthalamides and polyisophthalates having perfluorinated side chains were prepared from 5‐perfluoroalkylisophthaloyl dichlorides. The aromatic polyamides and polyarylates synthesized by conventional low temperature solution polycondensation and interfacial polycondensation, respectively, had inherent viscosities of 0.19 to 1.28 dL g⁻¹ in yields of 65 to 100%. Solubilies of the resulting polymers were improved by incorporating nonafluorobutyl groups but not improved by incorporating heptadecafluorooctyl groups. Although the effect on the glass transition temperature (T_g) of incorporating perfluoroalkyl groups into the aromatic polyamides or polyarylate backbone is great, the incorporation maintained the thermal stability of the polymers. In spite of the rigid nature of perfluoroalkyl groups, T_gs were decreased by incorporating perfluoroalkyl groups. The value of the contact angle of water on the aromatic polyamides films gradually increased with incorporation of the perfluoroalkyl groups. On the other hand, the value of the contact angle remarkably increased when perfluoroalkyl groups were incorporated into polyarylates. The Owens γs were also calculated for some aromatic polyamides by measuring contact angles of diiodomethane on the polymer films. The γs were estimated at 23‐37 mN m⁻¹ and about 10% of them were contributed by hydrogen bonding. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1135–1141, 1999