Decyl Groups Research Articles

Complexation behaviour of polymers with pendant cyclodextrin side groups

AbstractThe influence of the chain conformation on the formation of polymeric supramolecular complexes as well as the influence of the complexation on the conformation of the polymer chain has been studied. The complexation of pyrene into the cavity of β‐cyclodextrin (β‐CD) was investigated in aqueous solutions of β‐CD substituted poly(allylamine) (PAA) under variation of external parameters, i.e. temperature, pH, ionic strength and addition of urea. The observed changes of the complexation constant K for the formation of the 2:1 β‐CD/pyrene complex can be explained by a change of the chain flexibility which leads to a variation of the mean distance between neighbouring β‐CD‐moieties along the polymer chain. The intra‐chain association of the decyl group with β‐CD in PAA with co‐pendant decyl and β‐CD is disrupted by the addition of 1‐adamantanamine HCl resulting in a more extended structure of the polymer. The β‐CD moiety in PAA‐CD shows one order of magnitude greater affinity to 2‐(p‐toluidyl)naphthalene‐6‐sulfonate than the native β‐CD and the affinity increases further by the presence of decyl side groups.

Self-Organization and Opto-Electrical Properties of Poly (3-Alkylthiophene) Langmuir-Blodgett Films

We examined the self-organized properties of regioregular poly (3-alklylthiophene)s (HT-PATs) in Langmuir-Blodgett (LB) films by X-ray diffraction and FT-IR measurements. The HT-PATs showed self-organized properties due to their stereoregularity. The pendent decyl groups of HT-PDT formed more planar conformation and interdigitated structure. Electrical conductivities of doped HT-PATs/SA LB films were dramatically improved compared with random PATs, and HT-PDT films showed the highest in-plane conductivities among HT-PATs LB films.

Stepwise functionalization of mesoporous crystalline silica materials

Novel properties have been achieved in mesoporous crystalline silica materials by organic functionalization. In this study, localized functionalization and bifunctionalization of silica MCM-41 was attempted through the stepwise post-synthesis silylation. When MCM-41 was treated with various silylating agents for 6 hours before template removal, change in pore size only was observed without any change in surface area and pore volume. MCM-41 was difunctionalized with both decyl groups on edges of pores and methyl groups on inner surfaces of pores. Capillary condensation of water took place at higher relative pressure in MCM-41 with decyl groups on edges than in unsilylated MCM-41, whereas hydrophobic property was observed in MCM-41 which were difunctionalized with decyl groups on edges of pores and with methyl groups on inner surfaces of pores. This study shows that the manipulation of pore size and functionality with/without any change in surface area and pore volume and the combination of two different functionalities could be achieved in MCM-41 through the stepwise functionalization.

Control of migration time window and selectivity in electrokinetic chromatography with mixed polymeric pseudostationary phases

Control of migration time windows and the improvement of separation were achieved by utilizing mixed polymeric pseudostationary phases in electrokinetic chromatography (EKC) in water–organic solvent mixtures. Polyallylamine (PAA)- supported pseudostationary phases, one with hexadecyl groups (PAA-C 16) with the shorter migration times and the other with decyl groups (PAA-C 10) with the longer migration times, enabled the control of migration time windows when used as a mixture. PAA-C 16 provided better separation for a region with relatively small k′ values as in typical micellar EKC, while PAA-C 10 gave better separation for a region with relatively large k′ values as in reversed-phase liquid chromatography, the mixture of the two PAA derivatives resulting in better overall separations for a wide range of hydrophobic compounds. The migration time of a solute is determined by the relative contribution of each pseudostationary phase to the partition of the solute in a mixed carrier system. A theoretical explanation was provided by assuming the contribution of the two polymeric pseudostationary phases working independently. The migration time of the effective (imaginary) pseudostationary phase was shown to be in between the actual migration times of the two carriers, and can be different for each solute depending upon the relative contribution of the two pseudostationary phases to the solute partition.

ArF Chemically Amplified Negative Resist Using Alicyclic Epoxy Polymer.

We designed novel alicyclic epoxy polymers, poly(carboxy- tetracyclo[4.4.0.12, 5.17, 10]dodecyl (meth)acrylate-co-epoxyalicyclic acrylate) (poly(CTCDD(M)Ax-EPAAy)) for an ArF single-layer negative resist. These polymers became insoluble in a TMAH solution by an acid-catalyzed crosslinking reaction of the epoxy groups. A chemically amplified negative resist (consisting of the polymer having a 3, 4-epoxytricyclo [5.2.1.02, 6]decyl group and photoacid generator (PAG)) exhibited a resolution of 0.3 0-μm L/S using a 0.238% TMAH developer and an ArF exposure system (NA=0.55). We also investigated the influence of the polymer structures and additives on the lithographic characteristics. We found that the addition of alicyclic polyalcohol improved the resolution. The three-component resist system composed of the polymer which has 64% of the 2- epoxyethylnorbornyl group, 2, 3-dihydroxy-5-hydroxymethylnorbornane, and PAG resolved a 0.225-μm L/S pattern at 6.8mJ/cm2 with a 2.38% TMAH solution.

Submolecularly Resolved Polymerization of Diacetylene Molecules on the Graphite Surface Observed with Scanning Tunneling Microscopy

The photopolymerization of a monolayer physisorbed on graphite and containing diacetylene derivatives comprising a isophthalic acid head group and a decyl group as nonpolar tail was studied by scanning tunneling microscopy (STM). The submolecularly resolved STM image on the right depicts a domain boundary between an unpolymerized monolayer (lower domain) and a polymerized monolayer (upper domain).

Photo-cross-linked decyl methacrylate films for electrochemical and optical polyion probes.

Potentiometric and optical polyion probes based on photo-cross-linked thin films of decyl methacrylate (DMA) are described, and the effects of film composition on the response toward heparin are examined in detail. In accordance with existing theory governing potentiometric polyion response, lowering the amounts of plasticizer and tridodecylmethylammonium chloride ion exchanger within the film enhances its sensitivity toward heparin. Varying the cross-linker content of a DMA-based film, however, provides an additional mechanism to regulate its physical structure and, hence, the observed potentiometric polyion response. Films with low hexanedioldimethacrylate cross-linker content yield optimal potentiometric heparin detection limits (0.04 microM), suggesting a lower diffusion coefficient within such films, apparently due to interactions between adjacent pendant decyl groups. Increasing crosslinker content interrupts these interactions and facilitates diffusion. This knowledge is applied to optimize optical heparin sensing via DMA films covalently attached to glass substrates. When used in a limited volume/fixed exposure time measurement mode, such optically sensitive films can detect clinically relevant levels of heparin (0.5-5 units/mL) in undiluted human plasma.

Novel sugar bola-amphiphiles with a pseudo macrocyclic structure

Novel bola-amphiphilic compounds have been synthesised with d-glucose or d-galactose moieties as polar head groups. The sugar groups are coupled to the hydrophobic bridge, a chain of ten or twelve methylene groups, by an amide function at the C-2 site (2-alkylamido-2-deoxy- d-glucose derivative) or a glycuronamido function at the C-6 site. The former series is glycosylated with a cinnamyl group and the latter with octyl or decyl groups to afford pseudo macrocyclic compounds.

Synthesis of photochromic Benzodixanthene Analogues with 2-Pyridyl Group and Formation of Monolayers on Water Surface.

Nitrogen analogues of benzo[1, 2, 3-kl : 4, 5, 6-k′l′]dixanathene with 2-pyridyl group were synthesized from 1, 5-dichloroanthraquinone in six steps. After quaternization with iodoalkane, photochromic properties were investigated in ethanol or in toluene. The compound having a decyl group formed monolayer on water surface at 10°C.

Synthesis and Cation-Binding Properties of (1→6)-2,5-Anhydro-D-glucitol with 3,4-Di-O-Pentyl and Decyl Groups by Cyclopolymerization of 1,2:5,6-Dianhydro-D-mannitols

Abstract The cyclopolymerizations of 1,2:5,6-dianhydro-3,4-di-O-pentyl-D-mannitol (1b) and 1,2:5,6-dianhydro-3,4-di-O-decyl-D-mannitol (1c) were carried out using BF3OEt2 and t-BuOK. All the resulting polymers consisted of cyclic constitutional units, i.e., the extent of cyclization was 100%. The polymer structures for the polymerization with t-BuOK were (1→6)-2,5-anhydro-3,4-di-O-pentyl-D-glucitol (2b) and (1→6)-2,5-anhydro-3,4-di-O-decyl-D-glucitol (2c), whereas those with BF3O-decyl2 comprised 2,5-anhydro-D-glucitols as major units along with other cyclic ones. These polymers were soluble in n-hexane, CHCl3, and THF, but insoluble in water, which differs from the amphiphilic solubility of (1→6)-2,5-anhydro-3,4-di-O-methyl-D-glucitol (2a). The cation-binding properties of 2b and 2c were examined using alkali-metal picrates in order to compare them with those of 2a. The extraction yields for each cation decreased in the order of 2c < 2b < 2a. Every polymer exhibited a similar cation-binding selectivity in the order Cs+ > Rb+ > K+ ≪ Na+ > Li+. The ratio of K+ and Na+, K+/Na+, was 4.6 for 2a, 5.1 for 2b, and 7.1 for 2c in the increasing order 2a < 2b > 2c.

Synthesis and biological activity of fluorescent yeast pheromones.

The mating pheromones of Saccharomyces cerevisiae and derivatives of these pheromones have been synthesized and tested for biological activity in a solution-phase assay. The effects of native alpha-factor and a-factor on the growth of target cells in these assays were identical. A derivative of alpha-factor in which the amino terminus was modified with the fluorescent probe, 6-amino-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)hexanoyl, was only slightly less active than the unmodified pheromone. Derivatives of a-factor that contain various alkyl groups in place of the farnesyl moiety of the native pheromone were also synthesized and tested for biological activity. A derivative in which the farnesyl moiety is substituted with an unbranched decyl group exhibited activity identical to that of the natural pheromone, whereas a derivative that contains an unbranched pentyl group exhibited significantly lower biological activity than native a-factor. The derivatives of a-factor have in addition been modified to incorporate 6-amino-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) at the terminus of the alkyl chains. A derivative with the probe attached to a decyl chain displayed activity similar to that of the native pheromone, whereas the same modification on a pentyl chain produced a derivative with very low activity. The fluorescence spectra of the modified alpha-factor and a-factors were measured in methanol, aqueous solution, and aqueous solution containing phospholipid vesicles. The fluorescence of the probes depends on the environment of the pheromones and can be used to monitor the association of the pheromones with the lipid bilayer.

Polymeric phosphonium salts as a novel class of cationic biocides. VII. Synthesis and antibacterial activity of polymeric phosphonium salts and their model compounds containing long alkyl chains

AbstractVarious polymeric phosphonium salts containing long alkyl chains (C10C18) and their corresponding model compounds were prepared, which possess the same hydrophobic structure as that of the common disinfectants (quaternary ammonium salts), and their antibacterial activities were evaluated by means of the viable cell counting method against Staphylococcus aureus (Gram‐positive) and Escherichia coli (Gram‐negative). The polymer with the decyl group exhibited a higher activity than that of the corresponding model compound, particularly against the Gram‐positive strain. Furthermore, antibacterial activity of the polymers was found to decrease as the chain length increased. In contrast with the polymers, the antibacterial activity of the corresponding model compounds increased as hydrophobicity of the substituents increased. The antibacterial activity was strongly dependent on the structure, particularly on the length of the alkyl chain. © 1994 John Wiley &amp; Sons, Inc.

Synthesis and antimicrobial activity of dimethyl- and trimethyl-substituted phosphonium salts with alkyl chains of various lengths

Various phosphonium salts possessing single or double alkyl chains of various lengths (C10 to C18) were prepared as cationic biocides, and their antimicrobial activities against 11 typical strains of microorganisms including methicillin-resistant Staphylococcus aureus (MRSA) were evaluated. The phosphonium salts with long alkyl chains were found to show high levels of antimicrobial activity. Their activities depended strongly on the molecular structure, and a correlation between antimicrobial activity and molecular structure was observed. In the alkyltrimethylphosphonium salts, the bactericidal activity against S. aureus and Escherichia coli increased with increasing alkyl chain length, and the compound with the longest alkyl chain (C18) killed all the bacterial cells (ca. 10(7) cells per ml) within 30 min of contact at concentrations of 2.8 and 28 microM, respectively. In contrast, the bactericidal activity of dialkyldimethylphosphonium salts was found to decrease as the chain length of the substituents increased. It is significant that the phosphonium biocide containing double decyl groups exhibited the broadest spectrum of activity against microorganisms tested and showed the greatest bacteriostatic activity against MRSA (MIC = 0.78 micrograms/ml). Furthermore, we systematically investigated differences in bactericidal activity between the phosphonium salts and commonly available ammonium salts with the same hydrophobic structure. It was observed that the phosphonium salts showed an advantage over the corresponding ammonium salts in bactericidal activity and killing rate. For example, tetradecyltrimethyl- and didecyldimethylphosphonium chlorides killed all S. aureus organisms (ca. 10(7) cells per ml) within 60 and 30 min of exposure at 28 and 2.8 microM, respectively, while tetradecyltrimethyl- and didecyldimethylammonium chlorides which are representative of the existing cationic disinfectants did not kill all the bacteria even at the longest exposure time (120 min).

Synthesis and Properties of Bis (sulfonate) Types of Double-chain Surfactants Bearing a Sulfur Atom in the Connecting Part

Double-chain diol compounds and double-chain bis (sulfonate) surfactants, each bearing a sulfur atom as a sulfide, sulfoxide, or sulfone in the middle of the connecting part between two alkyl chains, were prepared. The emulsifying properties of the double-chain diols were studied in a mixed system of liquid paraffin and water. The double-chain bis (sulfonate) compounds bearing two decyl groups as the lipophilic part were easily soluble in water. Some surface-active properties of the surfactants bearing a sulfur atom in the connecting part were examined along with a similar type of double-chain surfactant having an oxygen atom in place of a sulfur atom. Displacement of the ether oxygen in the middle of the connecting group by the sulfide sulfur atom caused a slight decrease in cmc. A bulky group such as sulfinyl or sulfonyl in the middle of the connecting part negatively affected the micelle forming properties and the capacity to lessen surface tension. The double-chain bis (sulfonate) surfactants showed much greater lime-soap dispersing ability than sodium 1-dodecanesulfonate.

Thermodynamics of micellization of some decyl poly(oxyethylene glycol) ethers in aqueous urea solutions

The enthalpies of solution (text-decoration:overlineH2–H02) of some homogeneous decyl poly(oxyethylene glycol) ether (C10En) surfactants in monomeric and micellar states in 3 and 6 mol dm–3 aqueous urea solutions have been determined calorimetrically in the temperature range 288.15–318.15 K. The enthalpies of micellization (ΔmicH) and the heat capacities of monomeric (ΔCp, mono) and micellar (ΔCp, mic) forms as well as the heat capacities of micellization (ΔCp, m) have been evaluated from the enthalpy data. ΔmicH is less positive in aqueous urea solutions than in water and decreases with increasing urea concentration and temperature. ΔCp, m is relatively higher in aqueous urea solutions. The results indicate a decrease in hydration or structure around monomers in the pre-c.m.c. (critical micelle concentration) region and a relative increase in hydration of micelles due to enhanced hydrogen bonding between ethylene oxide groups and urea molecules in the post-c.m.c. region. Interactions between polyoxyethylene (hydrophilic) groups and urea seem to dominate over decyl (hydrophobic) group–urea interactions.

Inhibition of soybean lipoxygenase-1 by n-alcohols and n-alkylthiols

A series of n-alcohols and n-alkylthiols with carbon chains from 2 to 12 were examined for the inhibition of soybean lipoxygenase-1 (L-1). The alcohol produces a competitive inhibition, the extent of which increases with an increase in the carbon number of alkyl chain up to 8. Whereas the inhibition of the alkylthiol is noncompetitive, the extent of which is almost independent from the carbon number. From the behavior of p K i dependence on the carbon number of the alcohol, the decyl group appears to be optimum to bind to L-1. The thermodynamic analysis for the inhibition based upon van 't Hoff equation indicates positive enthalpy and entropy changes for the binding of the alcohol to the enzyme and negative enthalpy and positive to negative entropy changes for that of the alkylthiol. These observations suggest that the alcohol inhibits L-1 by binding of the hydrophobic alkyl tail to the catalytic site of the enzyme by a hydrophobic interaction. The alkylthiol inhibits by binding of the nucleophilic sulfhydryl head to a polarizable region of the enzyme and the alkyl tail to a hydrophobic region of the enzyme free from the steric hindrance as an anchor.

Poly(N‐acylethylenimine) copolymers containing pendant pentamethyldisiloxanyl groups. II. Thermal behavior and x‐ray diffraction study

AbstractTwo series of random copolymers of 10‐(pentamethyl disiloxanyl) decyl oxazoline (Si) with undecyl (U) (four copolymer compositions) and nonyl (N) (eight copolymer compositions) oxazolines over the whole composition range, with a total degree of polymerization of about 100, were studied by DSC and wide angle X‐ray diffraction. All the polymers are crystalline. For the N/Si copolymers, the melting points, normalized ΔH and ΔS of fusion are almost constant in a broad range of copolymer composition from 10 to 65 mol % of Si. The rationale for this behavior is that the copolymers crystallize two dimensionally, with the crystalline polymethylene plates separated by the bulky flexible pentamethyl disiloxanyl (P) groups. In this range, increasing Si only increases the distance between the plates. With more than 65 mol % Si, the bulky P groups interfere with the packing of the alkyl chains and change the crystallization behavior; the polymers show disordered packing as demonstrated by their X‐ray patterns and extremely low ΔH. In the U/Si copolymers, since the undecyl side chain has one more carbon than the decyl group to which the P group is attached, the P groups interfere much more strongly with the packing of the side chains than in the N/Si polymers. The copolymer melting points uniformly decrease as the concentration of Si increases. The plateau on the plot of normalized ΔH versus polymer composition is only from 10 to 50 mol % of Si. The average long spacings of the annealed polymers increase linearly from 24 Å (N/Si polymers) or 28 Å (U/Si polymers) to 34.1 Å with the increase of Si up to 50%. With more than 50% Si, the polymers have an identical lamellar thicknesses of 34 Å, within the experimental error. Copolymers with less than 75 mol % of Si can crystallize from hexadecane solutions forming gels down to polymer concentrations of 2‐3 wt %. The long spacings of the gels are almost identical with those of the pure crystalline polymers and independent of the polymer/solvent ratios. When hexamethyl disiloxane is added to the solutions, it can intercalate and the resulting crystalline gels have long spacings larger than those found in the absence of siloxane.

Chemical modification of poly(substituted‐acetylene). V. Alkylsilylation of poly(1‐trimethylsilyl‐1‐propyne) and improved liquid separating property at pervaporation

AbstractIn order to improve the separation characteristic at pervaporation, the introduction of several kinds of trialkylsilyl groups into poly(1‐trimethylsilyl‐1‐propyne) (PTMSP) was achieved via metalation of PTMSP followed by treating with trialkylchlorosilanes to afford trialkylsilylated PTMSP. Ratio of TMSP monomer unit and trialkylsilylated unit, x/y, was in the range of 95/5 to 80/20. All the chemically modified PTMSP membranes showed ethanol permselectivity at pervaporation of aqueous ethanol solution. Introduction of appropriate length of alkyl groups (methyl, ethyl, propyl, butyl, hexyl, octyl, and decyl groups) into PTMSP effectively enhanced the selectivity. However, excess introduction of octyl and decyl groups or introduction of dodecyl and octadecyl groups caused decrease of selectivity, of which the value was smaller than that of PTMSP membrane. Furthermore, acetone, acetonitrile, dioxane, and isopropanol were efficiently separated from their aqueous solutions at pervaporation through trimethylsilylated PTMSP membrane.

Studies on Trifluoromethyl Ketones. VII. Ene Reaction of Trifluroacetaldehyde and Its Application for Synthesis of Trifluoromethyl Compounds.

As an extension of our studies on the ene reaction of trifluoromethyl ketones, the ene reaction of trifluoroacetaldehyde was examined. The aldehyde reacted with various ene compounds as a good enophile in the presence of Lewis acids, among which methylaluminum dichloride workded best, though polymerization of the aldehyde caused by the Lewis acid among which methylaluminum dichloride worked best, though polymerization of the aldehyde caused by the Lewis acid often lowered the isolation yields of the ene reaction. The ene reaction products were successfully oxidized to trifluoromethyl β, γ-unsaturated ketones with Dess Martin reagent. Reduction of the ene reaction products followed by oxidation with Jones reagent gave saturated trifluoromethyl ketones. The β, γ-unsaturated ketone rearranged on thermolysis to an α, β-unsaturated ketone. These ketones obtained were converted to otehr types of trifluoromethyl compounds. Thus, the ene reaction of trifluoroacetaldehyde provides a versatile method for synthesis of many types of trifluoromethyl compounds. During this derivatization, a trifluoromethyl group was found to behave as a much larger substituent than a decyl group.

Aggregation of poly(vinyl acetate) or n‐decyl group grafted poly(allylamine) and crosslinking of trunk sequence in selective solvents

AbstractPoly(allylamine‐g‐vinyl acetate) [P(AAm‐g‐VAc), VAc content 33 mol%] and poly(allylamine‐g‐n‐decane) [P(AAm‐g‐CH), number of n‐decyl group/allylamine molecule was 4.4] were prepared by redox initiation of vinyl acetate polymerization on poly(allylamine) or a condensation reaction between amino group and 1‐bromo‐n‐decane. These polymers form aggregate in mixed solvents tetrahydrofuran/H2O and acetone/H2O. In acetone/H2O at a volume ratio which is good for poly(vinyl acetate) and not for poly(allylamine) (v/v = 65/35), the distribution of particle diameter shows a bimodal profile. These peaks vary with polymer concentration in the case of P(AAm‐CH). Poly(allylamine) sequences were crosslinked by 1,3‐dibromo‐2‐propanol in this solvent without macrogel formation. The crosslinking of particles with large diameter (several hundred nm) formed in rather concentrated solution was shown by electron micrograph. It was revealed that phase separation occurred in a particle with the proceeding of crosslinking reaction.