Showing papers on "Ether published in 1978"

A Novel Type of Polycondensation Utilizing Transition Metal-Catalyzed C–C Coupling. I. Preparation of Thermostable Polyphenylene Type Polymers

Abstract: Transition metal compounds including NiCl2(bpy) (bpy=2,2′-bipyridine), NiBr2(PPh3)2 (PPh3=triphenylphosphine), PdCl2(bpy), NiCl2, CoCl2, FeCl2, and FeCl3 catalyze polycondensation of di- and polyhalogenated organic aromatic compounds by dehalogenation with magnesium under mild conditions. Poly(p-phenylene), poly(m-phenylene), poly(oxybiphenylene), and poly(phenylenemethylene) were prepared from p-dihalobenzene, m-dichlorobenzene, bis(p-bromophenyl) ether, and α,p-dichlorotoluene. They have a high degree of polymerization and high thermal stability. Poly(p-phenylene), poly(oxybiphenylene), and poly(phenylenemethylene) have regularly repeated structures as proved by IR spectroscopy and X-ray powder diffraction. Polymerization of polyhalogenated aromatic compounds (1,3,5-trichlorobenzene and hexachlorobiphenyl) in tetrahydrofuran (THF) gave copolymers having aromatic nuclei and THF units. Polymerization of the haloaromatic compounds is considered to proceed through a mechanism in which consecutive cycles of ...

Use of aromatic-aliphatic ketones as photo sensitizers

Abstract: Aromatic-aliphatic ketones of the formulae I, II, III or IV ##STR1## wherein n is 1 or 2, Ar is an aryl radical, R1 and R2 are monovalent aliphatic, cycloaliphatic or araliphatic radicals, R3 is a direct bond or a divalent organic radical, X is a hydroxyl or amino group or the monovalent etherification or silylation products thereof, and X' is a divalent amino, ether or silyloxy group, Y is a direct bond or CH2 and Z is O, S, SO2, CH2 or C(CH3)2, are suitable sensitizers for the photopolymerization of unsaturated compounds and for the photochemical crosslinking of polyolefins. Some of these compounds are novel and can be obtained by methods analogous to those for obtaining the known compounds of this type.

The heat capacities and volumes of some low molecular weight amides, ketones, esters, and ethers in water over the whole solubility range

Abstract: The densities and heat capacities per unit volume of aqueous solutions of propionamide, methylacetate, ethylacetate, methylethylketone and diethylketone, and bis(2-ethoxyethyl)ether were measured o...

Ether-ester derivatives of cellulose and their applications

Abstract: A novel cellulose derivative provided in this invention is a mixed ester of an alkoxy or hydroxyalkoxy substituted cellulose ether, prepared by the esterification reaction of the ether with succinic anhydride and an anhydride of an aliphatic monocarboxylic acid. The cellulose derivatives are advantageous because of their capability of producing enteric coatings having sufficient flexibility without the use of a plasticizer as well as by their chemical and physical stability against moisture, and also by easy purification after completion of the esterification reaction. The coatings produced from the derivatives have a similar chemical and physical stability. The cellulose derivatives are useful for the enteric coating of pharmaceutical dosage forms and also for providing halation-preventing layers on photographic films.

Fluoropolymer blend coating compositions containing copolymers of perfluorinated polyvinyl ether

Abstract: Blends of PTFE and perfluorinated ether copolymers of TFE and perfluoro(propyl vinyl ether) provide coating compositions which have reduced crystallinity and useful lives superior to what would be expected from averaging the properties of the unblended resins themselves.

Palladation of dimethylhydrazones, oximes, and oxime O-allyl ethers: crystal structure of [Pd3(ON = CPriPh)6]

Abstract: The oxime of isopropyl phenyl ketone (Z-isomer) with NaOAc–Na2PdCl4 gives [Pd3(ONCPriPh)6] and whereas pinacolone oxime carbopalladates regiospecifically on the t-butyl group, the dimethylhydrazone carbopalladates only on the methyl group: acetone oxime O-allyl ether palladates on the central carbon atom of the allyl group with nucleophilic attack (e.g. by OMe–) on the terminal carbon atom.

Weldable coating compositions

Abstract: An improvement in a weldable coating for metallic substrates containing a high molecular weight epoxy or phenoxy resin, an electroconductive pigment such as zinc and a diluent such as a glycol ether wherein the improvement resides in replacing at least about 70 weight percent of said resin with a composition containing a low molecular weight epoxy resin such as the diglycidyl ether of bisphenol A, a phenolic hydroxyl-containing compound such as a phenolic hydroxyl terminated adduct of a diglycidyl ether of a diphenolic compound such as bisphenol A and a catalyst for effecting the reaction between the epoxy resin and the adduct.

Solubilization of steroid hormones by polyoxyethylene lauryl ether.

Abstract: As a further approach to an understanding of a relationship between the magnitudes of micellar solubilization and the hydrophobicities of solubilizates, steroid hormones (19 species) were selected to explore the meaning of the intercept b value. Two linear free energy relationships were established between the aqueous-polyoxyethylene lauryl ether micellar partition coefficient (K) and the partition coefficient (Poctanol) between aqueous solution and n-octanol. One consisted of the steroids carrying a fluorine atom at a carbon 9 and the other of those carrying no fluorine atom. The b value predicted that the fluorine steroids are solubilized in the outer layer of the mantle while the others are incorporated into rather inner position, which was consistent with the experimental results.

Complexes of platinum metals with crown ethers containing tertiary phosphine-substituted benzo groups

Abstract: Some benzo-crown ethers substituted in the arene ring are described, e.g. some 15-X-substituted benzo-[15-crown-5] ethers [1; X = I, CHO, CH2OH, CH2CI, CH2Ph2(Q), or CH2PBut2(Q′)] : 18-iodobenzo-[18-crown-6](2; X = I) and 15-iodo-16-methylbenzo-[15-crown-51](3; X = I) are also described. We have failed, however, to lithiate or to prepare a Grignard derivative of a benzo-crown ether. The model phosphines PR2[C6H3(OMe)2-3.4][4; R = Ph(L) or But(L′)] have also been synthesized. Reduction of (1; X = CHO) by Li[AlH4] gives, in addition to (1; X = CH2OH), a dicrown ether dibenzyl ether derivative (5; X = H). Similar reduction of 15-formyl-16-methylbenzo-[15-crown-5](3; X = CHO) gives only a dicrown diphenylmethane derivative (6). The chloromethyl derivatives react with Li[PPh2] to give the corresponding phosphines (4; R = Ph) and (1; X = CH2PPh2). and with PBut2H + I– followed by base (Na[OH]) their But analogues. Adducts of the sub-stituted crown ethers (1; X = CHO, Me, or I) with Na[SCN] have been prepared and some conductimetric studiesmade of complex formation with Nal. Complexes of the phosphines L, L′, Q, or Q′ of the types trans-[MCl(CO)-(phosphine)2](M = Rh or Ir), trans-[IrCl2H(CO)Q2], and trans-[IrMe(Cl)I(CO)Q2](also with L) have been prepared. The complex [PdCl2(NCPh)2] reacts with ether Q or L to give [PdCl2Q2] or [PdCl2L2](cis+trans isomers). When treated with Na[O2CMe] in 2-methoxyethanol, [PdCl2L2] undergoes cyclometallation to give [[graphic omitted]Ph2-2)(OMe)2-4,5}2Cl2](8; R = Ph, M = Pd). The complex [PdCl2(NCPh)2] with the bulky crown phosphine Q′ gives a mixture of trans-[PdCl2Q′2] and the corresponding cyclometallated complex; the complex (8; R = But, M = Pd) has also been prepared. A similar but more extensive series of platinum complexes has been made including mononuclear species formed by splitting the chloride-bridged systems with PPh3. Infrared, 1H and 31P n.m.r., and mass spectral data are given.

Molecular structure and conformation of ethyl methyl ether as studied by gas electron diffraction.

Abstract: The bond distances (rg) and angles (rα) in ethyl methyl ether have been determined by gas electron diffraction as follows: average of C(methyl)–O and C(methylene)–O=1.418±0.002 A, C–C=1.520±0.004 A, C–H=1.118±0.004 A, ∠C–O–C=111.9±0.5°, ∠O–C–C=109.4±0.3°, ∠H–C–H=109.0±0.4°, where uncertainties represent estimated limits of experimental error. The two rg(C–O) distances have been estimated independently with the aid of the rotational constants for the trans conformer reported by Hayashi et al.: C(methyl)–O=1.413±0.009 A and C(methylene)–O=1.422±0.007 A. The dihedral angle for the gauche conformer, 84±6°, and the relative abundance of the trans and gauche conformers in the gas phase at 20 °C, nt⁄(nt+ng)=0.80±0.08, have also been determined.

Surface-coating binders for cathodic electrocoating

Abstract: Surface-coating binders for cathodic electrocoating which comprise a protonized heat-curable reaction product (A), substantially free from epoxide groups, of (a) one or more Mannich bases, prepared from (a 1 ) one or more polyhydric condensed phenols which may or may not contain ether groups. (a 2 ) one or more secondary amines which contain one or more hydroxyalkyl groups, with or without one or more secondary amines which do not contain such groups, and (a 3 ) formaldehyde or a formaldehyde donor, with (b) one or more epoxy resins, Which binder also contains from 1 to 40% by weight, based on the total of (A) + (B), of a water-insoluble non-ionic resin (B), free from epoxide groups and containing urethane groups, which resin has been obtained by reacting a partially blocked diisocyanate or higher polyisocyanate with a reaction product of a polyepoxide and one or more low molecular weight compounds containing SH and/or OH groups. These surface-coating binders are especially used for the cathodic electrocoating of metal articles.

Radiation chemistry of carbohydrates. Part 16. Kinetics of HO2˙ elimination from peroxyl radicals derived from glucose and polyhydric alcohols

Abstract: Oxygenated aqueous solutions of H2O2 at pH 5.5 containing ethylene glycol, glycerol, meso-erythritol, D-xylitol, D-glucitol,myo-inositol, D-glucose, methyl α-D-glucoside, or bis-1-methylethyl ether as substrates were subjected to flash photolysis and the rise of conductivity measured as a function of time. Except for bis-1-methylethyl ether all substrates showed transient conductivity which decayed within several hundred ms. This transient conductivity is attributed to the formation of HO2˙ which dissociates into H+ and O2˙–. The precursors of HO2˙ are α-hydroxyperoxyl radicals derived from the various substrates. From the kinetic analysis it follows that the peroxyl radical of ethylene glycol shows one first-order elimination process (k 190 s–1). Two first-order processes are observed with the mixture of the peroxyl radicals of glycerol, D-xylitol, meso-erythritol, D-glucitol (k ca. 200 ca. 3 000 s–1), myo-inositol (k 470 and k 2 700 s–1), and methyl α-D-glucoside (k 480 and 2 000 s–1). Three parallel first-order processes are shown by the peroxyl radicals of D-glucose (k 400, 2 700, and >70 000 s–1). The simple assumption that the slow and fast elimination in the polyhydric alcohols is due to eliminations from the α, ω, and other positions is not sufficient to explain the results quantitatively. Neighbouring hydroxy-groups might influence the rate of elimination. The very fast component in D-glucose is ascribed to the peroxyl radical at C-1 of D-glucose. Peroxyl radicals at C-2, C-3, and C-4 are thought to eliminate at both a slow and a fast rate as do those of myo-inositol, that at C-5 not on the time scale of this experiment, whereas that at C-6 is expected to contribute to the slow elimination rate.

Polymer blends containing poly(vinylidene fluoride). Part III: Polymers containing ester, ketone, or ether groups

Abstract: To further investigate the nature of the specific interaction leading to the miscibility of poly(vinylidene fluoride), PVF2, with certain oxygen containing polymers, blends of PVF2 with poly(e-caprolactone), PCL, with poly(vinyl methyl ether), PVME, and with poly(vinyl methyl ketone), PVMK, were prepared. PVMK/PVF2 blends were found to be miscible while blends of PVME/PVF2 and PCL/PVF2 were found not to be miscible. These results show that the specific interaction with PVF2 involves mainly the carbonyl group rather than the entire ester group. The relative effectiveness of having this group in the chain or pendant to it is not yet resolved.

Polyalkylpiperidine derivatives of s-triazine

Abstract: of the Disclosure s-Triazine derivatives which contain, as substi-tuents in the 2-,4- and 6-position, at least one polyal-kylpiperdine radical and at least one N-methylolamino group or an ether thereof, are deffective stabilisers for plastics, in particular against light degradation. By virtus of their N-methylol group, they are to enter into a chemical bond with many plastics and this renders them stable to migration and elution.

Complexes of the lighter lanthanoid nitrates with 15-crown-5 and 18-crown-6-ethers: synthesis and characterization

Abstract: Complexes of lanthanoid trinitrates Ln(NO3)3 with 15-crown-5 ether 1 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd) and with 18-crown-6 ether 2 (Ln = La, Ce, Pr, Nd) having a 1:1 stoichiometry as well as 4:3 complexes with 2 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd) have been synthesized and characterized. All the isolated complexes are solvent free. At 170–220° the 1:1 complexes of 2 are quantitatively transformed into 4:3 complexes. X-Ray powder diagrams of the neodymium complexes with 2 indicate that both the 1:1 and 4:3 complexes are genuine compounds. All the 1:1 complexes show a characteristic IR. absorption band at 875–880 cm−1 absent from both the spectra of the free ligands and of the 4:3 complexes. The spectroscopic properties (IR. and electronic spectra, fluorescence lifetimes) of the complexes and the low magnetic moments of the Ln(III) ions in the complexes with Ln = Ce-Eu are indicative of a strong interaction between the lanthanoid ions and the crown ethers 1 and 2.

Bifunctionalized resins. Applications to the synthesis of insect sex attractants

Abstract: A 2% crosslinked divinylbenzene–styrene copolymer, incorporating benzoyl chloride groups, was used to monoprotect the symmetrical diol 1,10-decanediol. The corresponding monotrityl ether and cis-10-tetradecen-1-ol were prepared by this system, the latter by a Wittig reaction of a polymer-bound ylide with an aldehyde in the solution phase. A series of bifunctionalized resins containing proximally located trityl alcohol and benzoic acid groups was prepared in an attempt to prepare diol linked to the polymer via both a trityl ether and a benzoate linkage. It was established that these polymers bound 1,10-decanediol exclusively at one end only. Polymers, containing both trityl alcohol and benzoic acid groups in a random array or polymers containing proximally located trityl alcohol groups, gave mixtures of both monoprotected and doubly protected diol.

Ion–molecule reactions of methoxymethyl cations with some organic substrates studied by ion cyclotron resonance spectrometry

Abstract: The reactions of methoxymethyl cations generated from dimethyl ether with propene, butene-2, vinyl methyl ether, acetaldehyde and acetone have been studied. The collision complexes, generated with the olefines, may eliminate an olefine, a methanol and a formaldehyde molecule as shown by double resonance experiments. From deuterium labelling it is found, that in the cases of propene and butene-2 the elimination of an olefine is accompanied by an extensive H/D interchange in the collision complexes, which has been shown not to occur in the long-lived reactant methoxymethyl cations if the internal energy of the methoxymethyl cations is less than 2.3 eV. The H/D interchange in these collision complexes is reduced in the elimination of methanol and is almost completely suppressed in the elimination of formaldehyde. In reactions with vinyl methyl ether, however, the eliminations of methanol and formaldehyde from the corresponding collision complexes appear to proceed with extensive H/D interchange. These observations point to acyclic collision complexes rather than 4-membered ring complexes. The collision complexes generated with acetaldehyde and acetone decompose by elimination of formaldehyde only. Deuterium labelling has shown that the formaldehyde molecule contains the original methylene group of the reactant methoxymethyl cations. In addition, 18O labelling in acetone has shown that the original oxygen atom of the methoxymethyl cations is retained completely in the eliminated formaldehyde. These observations exclude any formation of 4-membered ring collision complexes and can only be explained by acyclic complexes. Possible mechanisms of all reactions mentioned are discussed in the light of these results.

Genetic Activity of Chlorophenols and Chlorophenol Impurities

Abstract: Studies were made of the genetic activity of 2,4,6-trichlorophenol, pentachlorophenol, and their impurities: 2,3,7,8-tetrachlorodibenzofuran 2,4,4′,6-tetrachlorodiphenyl ether 2,4,4′, 5-tetrachlorodiphenyl ether 4,5,6-trichloro-2-(2,4-dichlorophenoxy)phenol, (Cl5-predioxin) 4-chloro-2-(2,4-dichlorophenoxy)phenol, (Cl3-predioxin)

6,6'-Di-O-t-butyldimethylsilylsucrose: Studies on the rearrangements accompanying deblocking of such silyl ethers

Abstract: Use of limited amounts of t-butyldimethylsilyl chloride with sucrose in pyridide have led to the 6,6'-disilyl ether isolable in 36% yield without chromatography. Removal of the silyl ether groups from 2,3,4,1',3',4'-hexa-O-acyl- 6,6'-di-O-t-butyldimethylsilyl-sucroses has been studied with dilute acid and with tetrabutylammonium fluoride. The former reagent gave the expected hexa-O-acylsucroses, whereas the latter method yielded 2,3,6,1',3',4'-hexa-O-acylsucroses formed by a 4 → 6 acyl migration in the D-glucose moiety.

Preparation of esters of poly-(tetramethylene ether) glycol

Abstract: Esters of poly(tetramethylene ether) glycol are prepared by polymerizing tetrahydrofuran in a reaction mixture which contains, in addition to the tetrahydrofuran, and acylium ion precursor such as acetic anhydride, a polymeric catalyst which contains sulfonic acid groups and, optionally, a carboxylic acid such as acetic acid.

Determination of double bond positions in fatty acids with conjugated double bonds

Abstract: The positions of the double bonds in fatty acids with conjugated double bonds may be determined by mass spectrometry of the methyl esters of their trimethylsilyl ether derivatives obtained by hydroxylation of the double bonds followed by silylation of the resulting polyols. The method has been applied to trans-9,trans-11- and trans-10, trans-12-octadecadienoic acid.