21 research outputs found

    Foszforheterociklusok szintézise és hasznosítása = The synthesis and use of phosporus heterocycles

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    A kutatás három fő szálon futott, egyrészt az 5- és 6-tagú, másrészt a 7- és 8-tagú - ez utóbbi esetben áthidalt - P-heterociklusok területén, harmadrészt egy inverz Wittig-típusú reakció témájában. Újfajta foszfol- és a 3-as helyzetben foszforfunkciót tartalmazó 1,2,3,6-tetra- és 1,2,3,4,5,6-hexahidrofoszfinin P-ligandokat (ill. ez utóbbiak prekurzorait) tettük hozzáférhetővé, amelyeket átmeneti fémkomplexekké is átalakítottunk. A P-ligandok és a komplexek térszerkezetét felderítettük és ez utóbbiak egy részét katalizátorként is kipróbáltuk. Jónéhány dibenzooxafoszforint - közöttük optikai aktivitással rendelkező származékokat is - előállítottunk. A ligandok platina-komplexeit is elkészítettük. A kutatás másik vonalán új 7-foszfanorbornén, ill. 2-foszfabiciklo[2.2.2]oktén 2-oxid származékokat vezettünk be, egyrészt új szubsztituensek, másrészt új dienofilek alkalmazásával. A prekurzorokat reakcióképes intermedierek képzésén át foszforilezési reakciókban hasznosítottuk. Tanulmányoztuk a reakciók mechanizmusát és oxafoszfabiciklookténeket is vizsgáltunk. A harmadik témában a P-aril gyűrűs foszfin-oxidok és a dialkilacetiléndikarboxilát béta-oxofoszforánokat eredményező reakcióinak mechanizmusát derítettük fel és megfontoltuk az oxafoszfetének mint intermedierek lehetőségét. A béta-oxofoszforánokat kerülő szintézissel is hozzáférhetővé tettük és tanulmányoztuk néhány jellemző reakciójukat. | The research was performed in three topics, on one hand in the topic of 5- and 6-membered P-heterocycles, on the other hand in the field of 7- and 8-membered P-cycles including bridged derivatives, and finally in the topic of the inverse Wittig type reaction. New phosphole and 1,2,3,6-tetra- and 1,2,3,4,5,6-hexahydrophosphinine P-ligands - these latter with exocyclic P-function in position three - were made available that were also transformed to transition metal complexes. Stereostructure of the P-ligands and complexes was evaluated and a part of the latter was tested as catalyst. A number of dibenzooxaphosphorines and their platinum complexes were also prepared. In the second line of the research, new 7-phosphanorbornene- and 2-phosphabicyclo[2.2.2]octene 2-oxide derivatives were introduced and utilized in fragmentation related phosphorylation of nucleophiles. Beside the mechanistic studies, oxaphosphabicyclooctenes were also studied. In the third topic, the mechanism of the inverse Wittig type reaction of cyclic phosphine oxides and dialkyl acetylenedicarboxylate resulting in beta-oxophosphoranes was studied. Oxaphosphetes were considered as possible intermediates. The beta-oxophosphoranes were also prepared by an independent synthesis and some of their reactions were investigated

    Repair compositions for restoration of operated reinforced concrete structures

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    Power transmission lines (PTL) are strategic objects, the reliability of which depends on the life support of the country. Most of the currently operated power transmission lines were put into operation in the twentieth century, and by now there is a problem of assessing their technical condition, repairing them, if necessary, and maintaining them in a working condition. Defects that appear during the operation of reinforced concrete elements of power transmission lines have different localization and degree of manifestation, but typical is the destruction of the surface layer of concrete with exposure of rebar, more often at the base of the power transmission line. The aim of the work is to select the optimal composition of the repair mixture based on non-shrinking and expanding cements, ensuring reliable adhesion of the repair compounds to the concrete of the structure, which will restore the bearing and operational characteristics in the repaired reinforced concrete elements of the power transmission line at the design level

    Novel phosphonated poly(1,3,4-oxadiazole)s: Synthesis in ionic liquid and characterization

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    International audienceA new class of poly(1,3,4-oxadiazole)s (PODs) with pendant phosphonic acid groups was synthesized via direct polycondensation of dicarboxylic acids and their dihydrazides using ionic liquid, namely 1-methyl-3-propylimidazoluium bromide ([mpim]Br), as a reaction medium, and triphenyl phosphite as a reaction activator. The polymers were obtained with inherent viscosities equal to 0.46–0.58 dL/g in two steps starting from polyhydrazides formation followed by thermal polycyclization under high vacuum. Polymers derived from 5-phosphonoisophtalic acid were soluble in traditional organic solvents, while application of 2-phosphonoterephthalic acid resulted in formation of insoluble gels. Such properties as thermal stability, glass transition temperatures, water uptake, molecular weights and proton conductivity of novel polymers were investigated in detail. A comparison between common poly(1,3,4-oxadiazole)s and their phosphorylated or phosphonated analogs having the same polymer backbone demonstrated that PODs with pendant phosphonic acid groups possess approximately the same thermal stability, but greater glass transition temperatures along with reduced solubility. Transparent flexible films cast from such novel polymers were characterized by high tensile properties, namely tensile strength of about 90–100 MPa and elongation up to 8%. The proton conductivity values measured at the temperature range from 20 to 90 °C varied from 4 × 10−7 to 5 × 10−6 S/cm at 100% relative humidity
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