Studies of sorption properties of porous copolymers of 1-vinyl-2-pyrrolidone

Sorption of water, n-butanol and n-heptane into different porous copolymers of 1-vinyl-2-pyrrolidone was studied by thermogravimetry. It was shown that differences in interactions of these adsorbates with copolymers of different surface area and polarity can be monitored by this technique. The relative thermodesorption plot was introduced and used to analyze thermogravimetric data.     

The diels-alder chemistry of 1-vinyl-2-pyridones

The Diels-Alder chemistry of a series of 1-vinyl-2-pyridones using a variety of dienophilic species including dimethyl acetylenedicarboxylate, benzyne, maleic anhydride and methyl vinyl ketone has been explored in order to determine the generality of this method for generation of N-vinylisoquinuclidines. In general, the cycloaddition reactions lead to modestly high yeilds of the azabicyclooctane products. In the course of these studies, we noted that retro-Diels-Alder reactions of N-vinylisoquinuclidienones lead to generation of N-vinylisocyanates and a benzene fragment while the corresponding mono-unsaturated isoquinuclidenones form the corresponding pyridones by elimination of an ethylene unit. Lastly, the regio- and stereochemical courses for the π2+ π4 addition reactions of methyl vinyl ketone and 1-vinyl-2-pyridones were investigated. The major products from these reactions appear to result from reaction pathways predicted to be of low energy using first-order molecular orbital methods.     

Synthesis and optical properties of new 2-oxo-4-vinyl-2H-chromene-3-carbonitrile dyes

1. Download : Download high-res image (223KB)
2. Download : Download full-size image

     

Synthesis and properties Of 1-vinyl-2, 2, 3, 3-tetrafluorocyclobutane

The oxidation, hydrobromination, and bromoacetylation of 1-vinyl-2, 2, 3, 3-tetrafluorocyclobutane are investigated, with a view to preparing its oxide. It is found that the most convenient method of preparing this oxide is acetyl hydroperoxide oxidation of 1-vinyl-2, 2, 3, 3-tetrafluorocyclobutane.The authors wish to thank V. A. Klimova and N. V. Korshun for elementary analyses, and B. V. Lopatina and L. V. Orlova for spectroscopic analyses of the compounds prepared.     

Polymers of 2-vinyl-1,3-dioxolanes

Lewis acid-initiated polymerizations of 2-vinyl-1,3-dioxolanes have been studied. Evidence is presented showing at least three types of structural units in the polymer. Polymerization is propagated by 1,2 addition, by acetal ring opening, and by rearrangement, ring opening mechanisms. Polymerization is accompanied by the formation of a dimer consisting of a 1,4-dioxepane and 1,3-dioxolane ring. Film formers from methacrylate esters of vinyl dioxolane compounds are also described.     

Synthesis and properties of alternating copolymers of carbon monoxide with 5-vinyl-2-norbornene

The alternating cooligomers of carbon monoxide and 5-vinyl-2-norbornene have been first synthesized in the presence of catalysts based on palladium complexes containing N^N and P^P ligands. It has been shown that the insertion of carbon monoxide proceeds for the most part via a C(2)-C(3) bond of the norbornene ring. The degree of involvement of both olefinic bonds of diene in alternating copolymerization is decreased when the reaction is carried out in a protic solvent (methanol). The structure of terminal groups of the copolymers depends on the nature of a bidentate ligand and acid.     

Preparation and properties of co-oligomers of 1-vinyl-1,2,4-triazole with N-vinyl-2-phenylpyrrole

Novel water-soluble co-oligomers of 1-vinyl-1,2,4-triazole and N-vinyl-2-phenylpyrrole have been prepared by radical copolymerization. Copolymerization constants of the monomers and the parameters of cooligomers microstructure have been determined. 1-Vinyl-1,2,4-triazole is more reactive in the monomers pair. The prepared co-oligomers are thermally stable and reveal properties typical of paramagnetic organic semiconductors.

     

Cationic polymerization of 2-vinyl-1,3-dioxane

The cationic polymerization of 2-vinyl-1,3-dioxane initiated with triethyloxonium tetrafluoroborate was studied with particular emphasis on elucidation of the structure of the polymer. The polymer was a light yellow powdery material with a molecular weight of several thousands which was soluble in most organic solvents. The infrared and NMR investigations on the polymer, together with chemical analyses, showed that the polymer consisted of the three structural units I, II, and III, the contents of which were estimated to be 5–10%, 20–25%, and 65–70%, respectively. The formation of the structural units I and II was discussed in detail.     

Synthesis and properties of cross-linkable DNA duplex using 4-amino-2-oxo-6-vinyl-1,3,5-triazine

We synthesized the DNA oligonucleotide containing a new cross-linkable 4-amino-2-oxo-6-vinyltriazine (AOVT) nucleobase analogue (Et-AOVT) and evaluated these properties. Our results of the cross-link assay and thermal denaturing assay of duplexes containing AOVT demonstrated that the additional aza of AOVT has an impact on the duplex stability and crosslink properties. Our data suggests that the additional 5-aza of AOVT is involved in the hydrogen bonding with the complementary guanine, and this hydrogen bonding system successfully flipped the reactive vinyl group out to the major groove of the duplex demonstrating a new paradigm of a “cross-linkable duplex”.     

Reducing properties of 1,2-diaryl-1,2-disodiumethanes

1,2-Diphenyl- and 1-phenyl-2-(2-pyridyl)-1,2-disodiumethane efficiently dehalogenate vic-dibromoderivatives, affording the corresponding alkenes. The reaction proceeds rapidly, under mild conditions and is tolerant of a variety of functional groups (alcohol, carboxylic acid, ester and amide). This procedure was successfully extended to similar vic-disubstituted compounds.     

Novel catalytic rearrangements of 2-vinyl-1,3-thiazetidines

The thiazetidines (1) and (2) undergo a novel and high yielding rearrangement on hydrogenation with heterogeneous catalysis to give the thiazolidines (5) and (8) whilst reaction with the homogeneous catalyst Rh(Ph₃P)₃Cl results in the alternative high yielding rearrangement to give a thiazine.     

Structure and properties of 3-amino-1-vinyl-1,2,4-triazole

The reaction of acetylene with 3-amino-1,2,4-triazole forms two isomeric 3-amino-N-vinyl-1,2,4-triazoles. Their structures have been studied by PMR and IR spectroscopy and dipole moments. The high activity of the new vinyl compounds of the azole series in the addition of electrophilic reagents, in polymerization, and in complex formation has been shown.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1566–1569, November, 1973.     

1,2-Distanna-closo-dodecaborate--a rare example of a 1,2-distannylene ligand in transition metal chemistry

The coordination chemistry of the novel bidentate tin ligand 1,2-distanna-closo-dodecaborate is illustrated for the first time by reactions with molybdenum, platinum and gold metal complexes. Up to three clusters coordinate two metal centers in close proximity. For all these metal complexes the typical μ-bridging coordination mode was observed exclusively. Furthermore, two cluster anions react with dichloromethane via substitution of the chloride ions. The carbon functionalized tin cluster [Et(4)N](2)[CH(2)(Sn(2)B(10)H(10))(2)] and the coordination complexes [Et(3)NMe](6)[Mo(2)(CO)(6)(Sn(2)B(10)H(10))(3)], [Et(3)NMe](2)[{HPt(PEt(3))(2)(Sn(2)B(10)H(10))}(2)], [Et(4)N](2)[{HPt(PPh(3))(2)(Sn(2)B(10)H(10))}(2)] and [{(TP)Au}(2)(Sn(2)B(10)H(10))] (TP = PhP(o-Ph(2)PC(6)H(4))(2)) are fully characterized by multinuclear NMR spectroscopy, elemental analyses and crystal structure analyses.     

The synthesis of 4-vinyl-1,2,4-triazoles

The reaction of 1,2,4-triazole and 5-methyl-1,2,4-triazole with acetylene gives 4-vinyl derivatives. 1,2,4-Triazole-3-thione and its 5-methyl derivative gives N⁴,S-divinyl monomers.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 928–931, April, 1990.     

Synthesis and properties of 1-diphenylboryl-2-diphenylphosphino1,2-diphenylethene

Consecutive interaction of lithium phenylacetylide with triphenylborane and diphenylchlorophosphine gave 1-diphenylboryl-2-diphenylphosphino-1,2-diphenylethene, which is less reactive than dialkylborylphosphinoethenes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 378–380, February, 1993.The authors are greatful to the Tatarian Commercial-Mediatory Industrial Firm ELAZSNAB for the financial support of this research.     

Sorption on porous copolymers of 1-vinyl-2-pyrrolidone-divinylbenzene

Sorption properties of porous copolymers 1-vinyl-2-pyrrolidone-divinylbenzene (VP-DVB) were investigated by thermogravimetry. Water, n-butanol and n-heptane were used as sorptives. The current studies were performed for VP-DVB copolymers which were synthesized under different condition and vary in terms of porous structure. Additionally, VP-DVB 5 sample has more polar character comparing with other samples. It was demonstrated that porous structure of the adsorbent has the fundamental impact on the adsorption process but not only the value of specific surface area but also the pore diameter plays important role. Sorption of water is enhanced by the presence of micropores and polar character of the adsorbent.     

Reactivity differences between nickel and palladium complexes bearing 1,2-diphosphino-1,2-dicarba-dodecaborane ligand

AgOTf (OTf = trifluoromethanesulfonate) shows the reactivity differences when it reacts with carborane complexes [MCl₂{(PPh₂)₂(C₂B₁₀H₁₀)}] (M = Ni (2), Pd (3)). The reaction of AgOTf with the palladium complex 3 affords [Pd₂(μ-OTf)₂{(PPh₂)₂(C₂B₉H₁₀)}₂] (4) in high yields, while corresponding reaction between the nickel complex 2 and AgOTf leads to the formation of binuclear complexes [Ni{(PPh₂)₂(C₂B₉H₁₀)}](μ-Cl)₂[Ag{(PPh₂)₂(C₂B₁₀H₁₀)}] (5) and [Ag₂(μ-Cl)₂ {(PPh₂)₂ (C₂B₁₀H₁₀)}₂] (6). The carborane cage of complexes 4 and 5 were broken to form nido-carboranes. It is believed the group 10 metals themselves play an important role in opening the closo-carborane skeleton. Directly stirring [(PPh₂)₂(C₂B₁₀H₁₀)] with AgOTf afforded [Ag₂(μ-OTf)₂{(PPh₂)₂(C₂B₁₀H₁₀)}₂] (7), which is also used to react with 2 and 3. The reaction between 2 and 7 gives only 4 in high yields, however, stirring the mixture of 3 and 7 affords [Pd₂(μ-Cl)₂{(PPh₂)₂(C₂B₉H₁₀)}₂] (8), [Pd{(PPh₂)₂(C₂B₉H₁₀)}₂] (9) and 6. All these complexes have been characterized by IR, ¹H NMR, ¹¹B NMR and elemental analyses. Complexes 2, 4-9 have also been determined by single-crystal X-ray diffraction analyses.     

Mechanistic investigation of the isomerization of 5-vinyl-2-norbornene

The isomerization reaction of 5-vinyl-2-norbornene (VNB) to 5-ethylidene-2-norbornene (ENB) has been performed using a catalytic system consisting of an alkali metal hydride and an amine. Among various amines tested, only aliphatic 1,2-diamines exhibited the activity for the isomerization. The isomerization was also affected by the alkali metal hydride employed. The activity of the alkali metal hydride increased with the increasing size of alkali metal: KH > NaH > LiH. A series of electron paramagnetic resonance (EPR) and UV-vis experiments on the active species suggest that the isomerization of VNB proceeds through a radical mechanism.