Facile and Versatile Room-Temperature Synthesis of N,N-Disubstituted Cyanoacetamides from Malonic Ester Chloride

A general method for the synthesis of various N,N-disubstituted cyanoacetamides from readily available methyl malonyl chloride and secondary amines, including sterically demanding aliphatic and aromatic amines, is described.     

AFM study of advanced composite materials for organic photovoltaic cells with active layer based on P3HT:PCBM and chiral photosensitive liquid crystalline dopants

Advanced composite materials aimed for construction of organic photovoltaic cells have been studied by atomic force microscopy (AFM). The composites are based on poly(3-hexylthiophene) (P3HT), [6,6]-phenyl C₆₁-butyric acid methyl ester (PCBM) and two different chiral photosensitive liquid crystalline (LC) materials. The objective of the study was to examine the nanoscale morphology of the active layer without and after annealing at specific temperature. The preliminary results of AFM observation of the morphological changes done on the investigated composites revealed an increase in the surface ordering. The surface area ratio decreases for both studied composites, while the basic roughness parameters (S_a and S_q) have been found toughly dependent on the structure of the photosensitive LC dopant.     

Metallomesogens: enaminoketone derivatives of the 3-oxa, 3-thia- and 3-selena-butyric amides

Liquid crystalline Ni(II) and Cu(II) complexes of tetradentate ligands, enaminoketones and 3-oxa; 3-thia- and 3-selena-butyramides were synthesized and examined. The compounds show very low C ₁ symmetry resulting from the chiral donor atoms — oxygen, sulphur and selenium — incorporated in the butyric amide moiety. This chirality can be observed in NMR studies. The complexes exhibit enantiotropic as well as monotropic calamitic SmA and N phases.     

Alignment of liquid crystal and dichroic dye molecules in mixed Langmuir and Langmuir-Blodgett films

A study of dichroic dye-liquid crystal mixtures (guest-host systems) in monolayers formed at a gas-liquid interface (Langmuir films) and at a solid surface (Langmuir-Blodgett films) has been made. As a host 4- n -octyl-4′-cyanobiphenyl (8CB) or 4- n -pentyl-4″-cyano- p -terphenyl (5CT) were chosen, while three dichroic azo dyes with various molecular structures were used as guest species. The dyes were added to the liquid crystal matrices at a concentration corresponding to the whole range of molar fractions and the surface pressure-mean molecular area isotherms for Langmuir films were recorded. On the basis of the isotherms, conclusions about the molecular organization and the miscibility of the components in the ultrathin films were drawn. The Langmuir films were transferred onto the quartz plates at surface pressures below the collapse point. The polarized absorption spectra of the Langmuir-Blodgett films were recorded and information about the alignment and intermolecular interactions in the mixtures of the non-amphiphilic dichroic dyes and the liquid crystals with strongly polar terminal groups were obtained.     

Stereoselective Synthiesis of Both Enantiomers of Disparlure from D-Glucose

D-Glucose was transformed stereoselectively into (7R,8S)8-benzyloxy-7-hydroxy-2-methyl-9-octadecene from which both enantiomers of disparlure, (7R,8S)-(+)-and (7S,8R)-(-)-7,8-epoxy-2-methyloctadecane, sex pheromone of the gypsy moth, were obtained in four and three steps, respectively.     

Microsynthesis of Dianhydrohexitols

Abstract

Conditions have been established for the microsyntheses of dianhydro-hexitols by reaction of 1, 4-monoanhydro-D, L-galactitols and 1, 5-monoanhydro-D-galactitol as well as of 1, 4- and 1, 5-monoanhydro-D-glucitols and -D-mannitols with tosyl chloride in pyridine followed by cyclization of the resulting 6-O-tosyl derivatives in methanolic solution of sodium methoxide. The dianhydrohexitols were formed by intramolecular nucleophilic substitution of the C-6 O-tosyl group with a properly stereochemically oriented hydroxyl group.

Components of the mixtures were separated by capillary gas chromato-graphy using columns coated with SP-2340 and identified by GC-MS. The identities of the synthesized dianhydrohexitols were confirmed by comparison with the GC retention times and mass spectra of authentic samples.     

(Co)polymers of oligo(ethylene glycol) methacrylates—temperature‐induced aggregation in aqueous solution

The synthesis and aggregation behavior of well‐defined thermosensitive (co)polymers of oligo(ethylene glycol) methacrylates (POEGMA) in aqueous solutions were investigated. The cloud points of the POEGMAs solutions were determined by turbidimetry and dynamic light scattering. For POEGMA (co)polymers the cloud point temperature (T_CP) increased linearly with increasing content of more hydrophilic comonomer. The mesoglobules formed by POEGMAs in dilute aqueous solutions above T_CP were studied by light scattering. The size of mesoglobules depended on the concentration and the heating procedures. The aggregates became smaller with decreasing initial concentration of polymer and increasing rates of temperature change. By selecting the proper heating and dilution procedures, the influence of the (co)polymer structure on the size of the mesoglobules could be determined. The size of the mesoglobules decreased with the length of the OEG side chains and increased with increasing content of more hydrophilic comonomer. The light scattering parameters of the mesoglobules—A₂ values and shape factors ${R_{\rm g}\over R_{\rm h}}$ —suggested that the hydrophilic OEG side chains placed at the periphery of the mesoglobules in direct contact with the surrounding water controlled the size of mesoglobules and their stability. Shape factors for all POEGMA mesoglobules indicated that the mesoglobules remained highly hydrated after formation. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Supramolecular synthons and pattern recognition in adenine amides – synthesis,structures and thermal properties

An effective method for the synthesis of novel adenine amides was developed and successfully implemented, leading to 4-propyloxy-N-(9H-purin-6-yl)benzamide (1) and 4-dodecyloxy-N-(9H-purin-6-yl)benzamide (2). The compounds were fully characterised by means of spectroscopic (¹H NMR, ¹³C NMR, FT-IR) and thermal (TG, DSC) analysis. The crystallographic analysis revealed that the formation of supramolecular chains relies on hydrogen bonding between amide functionalities. All supramolecular synthons found in the crystal structure of 1 were confirmed with the temperature-dependent IR method. The temperature-dependent IR method is useful in determining supramolecular interactions for compound 2, for which the crystal structure could not be obtained. A detailed analysis of temperature-dependent FT-IR spectra was used for the first time to identify the hydrogen bonds that exist in the solid state of our compounds; it can therefore be considered a promising method for the pattern recognition of hydrogen bonding in supramolecular chemistry.     

Preparation and Oxidative-Chlorination Splitting of Nitro Derivatives OF 1,4-Dithiino[2,3-C:5,6-C′]Diquinoline as a Source of 4-Substituted 5- and 8-Nitro-3-Quinolinesulfonic Acid Derivatives

Abstract

Treatment of 1,4-dithiino[2,3-c:5,6-c′]diquinoline (a thioquinanthrene) (1a) with an excess of nitrating mixture (0 °C, 14 days) led to a mixture of mono- and dinitrothioquinanthrene 7-oxides 2b–e and 2f–h. This mixture was: (i) reduced to a mixture of mono- and dinitrothioquinanthrenes 1b– e, or (ii) oxidatively chlorinated with a gaseous chlorine/80% acetic acid/hydrochloric acid system to a mixture of 4-chloro-3-chlorosulfonylquinoline 3a and its 5- and 8-nitroderivatives 3b and 3d. Sulfochlorides 3a– d were independently synthesized from 3,4′-diquinolinyl sulfides 4 and converted to the respective 4-dimethylamino-3-quinoline-N,N-dimethylsulfonamides 9a–d.     

β-( N -Acylamino)vinylphosphonium Salts--Synthesis and Properties

A reaction of g -carbonyl phosphorus ylides with imidoyl halides gives hitherto unknown g -( N -acylamino)vinylphosphonium salts. The same product can be obtained using the N-monosubtituted amide/Ph 3 PBr 2 /Et 3 N system instead of imidoyl halide. The key step of the reaction probably involves an intramolecular [1,3] O-to-N migration of the vinyl group, converting the primary O -imidoylation product into g -( N -acylamino)vinylphosphonium salt.