Über die elektrische leitfähigkeit oligomerer und polymerer 2.5-Dimethoxyphenylen-vinylene

The electrical conductivities of the earlier published oligomeric and polymeric 2.5-dimethoxyphenylene vinylenes¹ were measured at room temperature to about 120°C. The maximum value for the σ298°K was 2.0·10^?6Ω^?1·cm^?11 with an activation energy of 0.34 eV. The 1.4-linked compounds have a higher conductivity than the compounds with a 1.3-linkage. The 2.5-dimethoxy substitution of the phenylene units causes a considerable increase of the conductivity contrary to the unsubstituted phenylene units.     

Über Polyarylenalkenylene und Polyheteroarylenalkenylene, 4. Synthesen und Charakterisierung von Poly(2,7-fluorenylenvinylenarylenvinylen)en und einigen dazugehörigen Oligomeren

Some poly(2,7-fluorenylenevinylenarylenevinylene)s ( 3a–c ) and some of their corresponding oligomers were prepared via the Wittig-reaction starting from 2,7-fluorenedicarbaldehyde ( 1 ) and “mono- and bis-Wittig-salts” of the benzene and thiophene series. 2-Fluorenecarbaldehyde ( 6 ) submitted to the same reaction with “mono- and bis-Wittig-salts” gave an additional series of oligomers. These polymers and oligomers were characterized by elemental analyses and by their IR- and electronic spectra–the oligomers in addition by their mass spectra. The electrical conductivities of the polymers and oligomers were investigated as well as the thermooxidative degradation of the polymers and of some oligomers.     

Über Polyarylenalkenylene und Polyheteroarylenalkenylene, 10. Synthesen und Charakterisierung von Poly-(3,5-dimethylthiazolo [4,5-f]benzthiazoldiium-2,6-diylvinylenarylenvinylen)en und einigen Modellverbindungen

From 2,3,5,6-tetramethylthiazolo [4,5-f]benzothiazoldiium diperchlorate ( 2 ) and dialdehydes of the benzene and the thiophene series the corresponding poly(3,5-dimethylthiazolo[4,5-f]benzothiazoldiium-2,6-diylvinylenarylenevinylene diperchlorate)s 6a–c were synthesized via Knoevenagel condensation. Analogous reactions with comparable monoaldehydes gave a series of model compounds 4a–c . The structures were confirmed by elemental analyses and by IR and electronic spectra. In addition, the model compounds were characterized by their ¹H NMR and mass spectra. The electrical dark conductivities of all substances and the thermooxidative degradation of the polymers were studied.     

Über Polyarylenalkenylene und Polyheteroarylenalkenylene, 9. Synthesen und Charakterisierung von Poly(5-methylthiazolo-[4,5-f] benzthiazolium-2,6-diylvinylenarylenvinylen)en und einigen Modellverbindungen

Starting from 2,3,6-trimethylthiazolo[4,5-f] benzothiazolium perchlorate ( 2b ) some poly(5-methylthiazolo[4,5-f] benzothiazolium-2,6-diylvinylenarylenevinylene)s ( 11a–c ) and some corresponding model compounds ( 10a–c ) were prepared via Knoevenagel condensation with mono-and dialdehydes ( 4 and 6 ) of the benzene and thiophene series. Additional series of model compounds ( 5a–c, 7a–c, 8a–f , and 9a–f ) were obtained from 2,3,6-trimethylthiazolo[4,5-f]benzothiazolium iodide ( 2a ) or 2,3-dimethylbenzothiazolium iodide ( 3a ), respectively, or from the perchlorates ( 2b and 3b ) submitted to the same reaction with mono-and dialdehydes. The structure of these model compounds and polymers was confirmed by elemental analyses, IR and electronic spectra. The model compounds are also characterized by their mass spectra, and in the case of sufficient solubility by ¹H NMR spectroscopy too. The electrical conductivities of all compounds and polymers and the thermooxidative degradation of the polymers were investigated.     

Über die synthese polymerer indophenine und deren elektrische eigenschaften

Condensation of bis-{dioxopyrrolino[2′.3′: 1.2;2″.3″: 5.4]} benzene with thiophene and reaction of a polymer containing poly[6-vinylisatin] with isatin and thiophene gave two polymers containing indophenine units of different type. These products are polymeric vat dyes. The polymeric indophenine I with a system of conjugated double bonds and coplanarity in the molecule has a spezific dc conductivity of σ = 1.1 · 10^?4 Ω^?1 · cm^?1 at 25°C and a pressure of 1500 kp · cm^?2. The spin contents is 1.9 · 10²⁰ spins · g^?1. The electrical properties and the spin contents of some redox polymers containing indigoid dyes respectively quinoid structure were also investigated.     

Die Wirkung von Penicillin und Streptomycin auf Meningokokken bei alleiniger und kombinierter Anwendung

Ohne Zusammenfassung     

Über die Druckabhängigkeit der viskoelastischen und physikalisch-chemischen Eigenschaften von Polymeren, 7. Einfluß des Lösungsmittels para-Xylol auf das Schmelzen und Kristallisieren von Polyethylen

Melting and crystallization of polyethylene (PE) with various amounts of xylene is investigated by pressure dependent volume-temperature curves. These can be calculated by a reduction formula described earlier. Flory's formula for lowering of the melting point of polymers by solvents proves to be applicable also for high pressures.     

Über Darstellung und die Bromierungseigenschaften polymerer N-Brom-(phenyl-4-vinylphenyl)methanimine

Polymeric (phenyl-4-vinylphenyl)methanimines ( 5 ) were obtained by reaction of crosslinked and also of linear copolymers from p-lithiumstyrene and styrene, with benzonitrile and subsequent treatment with methanol. They could be brominated at the nitrogen-atom in different ways. With the resulting polymeric N-bromo(phenyl-4-vinylphenyl)methanimines ( 7 ) suitable monomeric substrates could be brominated in aromatic side chains and in allylic position. The resulting debrominated polymers could be regenerated by repeated bromination at the nitrogen atom.     

Über den aufbau von block- und pfropfcopolymeren

After briefly introducing the basic possibilities for the formation of graft and blockcopolymers, the important methods of the radical-initiated block and graft copolymerization are discussed on the basis of the characteristic examples, which are available in the literature. Thereafter the discussion is carried out on the few a t that time known syntheses in the field of the anionic block copolymerization, which then finally loads to the own work with polyfunctional macromolecular anionic initiators. Thus the addition of dialkylaluminium hydrides to macromolecules with C?C double bonds in side chains or at chain ends, and treating the products with transitionmetal halides (e.g. TiCl₄), macromolecular ZIEGLER -NATTA -Catalysts are formed. These initiate graft and block copolymerization of ethylene and α-olefines, whereby the poly-α-olefine molecules, which are already grown, can have a stereoregular structure. Macromolecules containing RC?NM linkages are formed on addition of organometallic compounds of lithium (LiR) or magnesium (MgRhal) to the N≡C triple bond in styrene-acrylonitrile copolymers, and they initiate anionic graft copolymerization of acrylonitrile (AN), methylmethacrylate (MMA), 2-vinylpyridine (2-VP), and 4-vinylpyridine (4-VP). Reactions of macromolecules containing O?C, N≡C, or C?C linkages in side chains with sodium or naphthalene sodium give macromolecular radical anions (e.g., high-polymeric ketyls in the case of poly-p-vinylbenzophenone) or dianions, formed by electron-transfer from the metal to the multiple bond. Both the radical anions and the dianions initiate anionic graft copolymerization of AN, MMA, 2-VP, 4-VP, butadiene, and styrene, and in this way pure graft copolymers are formed, free from “backbone molecules” and from homopolymers of the grafted monomer. Pure graft copolymers are formed also on use of macromolecular organometallic initiators, such as those formed by metallation of poly-4-chlorostyrene or 4-chlorostyrene styrene copolymers with stoichiometric amounts of naphthalene sodium. Since the anionic end groups of the growing side chains remain “living” during these processes, second and third monomers can be added to afford graft copolymers whose side chains are block copolymers. If the growing chains are terminated, e.g., by chlorosilanes containing functional groups, then reactive end groups are introduced into the side chains. Finally, graft and, in particular, block copolymers can be obtained when “finished” macromolecules containing very reactive silicon side or end groups (e.g., H? Si-, Cl? Si-, HO? Si-, CH₂?CH? CH₂? Si-groups) are joined together by chemical reactions. These methods open a route to block copolymers having stereoregular blocks. Macromolecules containing suitable functional groups attached to silicon atoms also provide a bridge to anionic processes. For instance, macromolecules containing p-vinyl-phenylsilicon end groups surprisingly react readily with sodium to radical anions which effect block copolymerization of vinyl monomers.     

Die Anwendung von Sekretin und Cholecystokinin-Pankreozymin

Ohne Zusammenfassung     

Die darstellung von N-formylaminosäure-trialkylsilylestern. Über die Si-N-bindung. XXV

The reaction of aminoacids with trimethylchlorosilane in a mixture of formamide n-hexane and pyridine leads to the formation of N-formylaminoacidtrimethylsily lesters.     

Über den einfluß von reglern auf die polymerisation des trioxans

Chain transfer of cationic trioxane polymerisation with several transfer agents was investigated, showing that during polymerisation a hydride shift takes place as side-reaction. This was confirmed by analytical investigations. The intramolecular hydride shift yields methyl cations which on their part release polymerisation or transacetalisation. Hydride shift and transacetalisation are characteristic for the cationic polymerisation of trioxane and formaldehyde. Several new chain transfer agents such as esters of boric acid and alkyl substituted aromatic compounds were found. Furthermore polyoxymethylenes with unsaturated, nitrile, and peroxy end groups were prepared.     

Die Autoxidation von Cumol in Gegenwart von Chelaten monomerer und polymerer Schiffscher basen

Transition metal chelates 2a–e, 4a,b , and 6a,b of the monomeric and polymeric Schiffs' bases ( 1, 3 , and 5 , from salicylaldehyde and 2-aminophenol, and 2,4-diamino-5-hydroxyphenol, resp. as well as from 2,5-dihydroxyterephthalaldehyde and 2,4-diamino-5-hydroxyphenol) were prepared, and their catalytical properties in the autoxidation of cumene were studied. The activity decreases in the order Mn>Co>NI>Cu>Zn and also with increasing molecular weight of the Schiffs' base. The compounds catalyze also the decomposition of cumene hydroperoxide, the chelates of Mn being the most effective.     

Die Anwendung von Follikelhormonen und Oestrostilbenen beim Mann

Ohne Zusammenfassung     

Über den Einfluß aromatischer Azoverbindungen auf die radikalische Polymerisation von Styrol

The retardation of the free radical polymerisation of styrene by substituted azobenzenes was investigated. In model experiments it was shown, that the decomposition products of dibenzoyl peroxide react with aromatic azo compounds yielding hydrazyls, which could be identified by ESR spectra. The formation of hydrazyls is responsible for the retardation of the styrene polymerisation in presence of azobenzenes; the effectivity depends on the stability of the formed hydrazyls.     

Über die depolymerisation von polyoxymethylendiolen,katalysiert durch carbonsäuren. 38. Mitt. Über polyoxymethylene1

After reviewing previous work on the mechanism of the acid catalyzed degradation of polyoxymethylene diols the depolymerization is investigated in 1% solution in nitrobenzene at 135°C under the influence of various carboxylic acids. Phenylacetic acid does not noticeably cleave chains but only catalyzes depolymerization at the hemiacetalic chainends. The rate of depolymerization increases roughly proportionally with the concentration of acid and with the reciprocal of the degree of polymerization. During degradation the average degree of polymerization remains almost constant. These results are not quite consistent with any of the discussed reaction mechanisms.