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1.	Aas, Wenche, et al. (författare) Equilibria and dynamics in binary and ternary uranyl oxalate and acetate/fluoride complexes 1999 Ingår i: Journal of the Chemical Society - Dalton Transactions. - : Royal Society of Chemistry (RSC). - 0300-9246 .- 1364-5447. ; :8, s. 1311-1317 Tidskriftsartikel (refereegranskat)abstract The formation of ternary UO2(ac)pFq2-p-q (p = 1 or 2 and q = 1-3) complexes, and their equilibrium constants were investigated by potentiometric titrations and 19F NMR spectroscopy. The equilibrium constants have been determined from the emf data in a NaClO4 medium at constant sodium concentration, [Na+] = 1.00 M at 25°C, except for the UO2(ac)F32- complex where 19F NMR at -5°C was used. The magnitude of the equilibrium constant for the stepwise addition of fluoride indicates that prior co-ordination of acetate has only a small effect on the subsequent bonding of fluoride. The acetate exchange in the ternary UO2(ac)F32- complex was studied using 19F NMR. Through magnetisation transfer experiments, it was possible to confirm the provisional mechanism from a previous study and also the consistency of the rate constants for the five different exchange pathways required to describe the fluoride exchange. The exchange takes place via the intermediate UO2F3(H2O)2-, indicating that the acetate exchange follows an interchange mechanism with solvent participation in the transition state. The rates and mechanisms of the ligand exchange reactions in UO2(ox)2(H2O)2- and UO2(ac)2(H2O) have been studied using 13C NMR techniques at -5°C. The rate law is v = k-[complex][ligand], and the second order rate constant and the activation parameters for both systems have been determined. The reactions most likely take place through an Eigen-Wilkins type of mechanism, where the first step is a pre-equilibrium of an outer-sphere complex followed by a rate determining exchange of water. The rate constants for the water exchange reactions are very similar to that in UO2(H2O)52+. The information from the binary oxalate system rules out the formation of UO2(ox)2(H2O)2- as an intermediate in the exchange reactions in the previously studied UO2(ox)2F3-, also in this case confirming a previously suggested exchange mechanism. The H+/D+ isotope effects and a linear free energy relationship suggest that the main catalytic effect of H+ on ligand exchange rates is due to the formation of a protonated precursor. Hence, the catalytic effect depends on the basicity of the ligand and the site for the proton attack.
2.	Batta, Gy., et al. (författare) C‐19 configurational assignments in some morphine derivatives by homonuclear NOE 1992 Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 30:13, s. S96-S104 Tidskriftsartikel (refereegranskat)abstract Azidolysis‐thermolysis of C‐19 diastereomer tosyl esters of morphine derivatives resulted in the formation of a new substituted 4‐azatetracyclo [4.4.02,4.03,8] decane ring system. As the course of such transformations depends on the chirality of C‐19, its relative configuration was determined both in the starting materials and in the new compounds. To this end a semiquantitative 1H{1H} NOE interpretation was combined with MMX molecular mechanics. Interestingly, both in the starting materials with a rotating C‐7—C‐19 bond and in the fairly rigid aziridine ring‐containing products, the same (H‐8α{19‐Me}) NOE effects were the most informative on the stereochemistry. In addition full a priori 1H and 13C assignments of 13 compounds are presented.
3.	Csende, F., et al. (författare) Copper(II) chloride as an efficient reagent for the dehydrogenation of pyridazinone derivatives 1995 Ingår i: Synthesis (Stuttgart). - : Georg Thieme Verlag KG. - 0039-7881 .- 1437-210X. ; :10, s. 1240-1242 Tidskriftsartikel (refereegranskat)abstract A new procedure is described for the preparation of pyridazinones from 4,5-dihydropyridazinones under mild conditions with CuCl2 in MeCN via halogenation and spontaneous HCl elimination. For the trans-hexahydrophthalazin-8(1H)-one 1B*, the HCl elimination is five times faster than for the corresponding cis isomer 1B.
4.	Csende, F., et al. (författare) Partial dehydrogenation of saturated 4-phenyl-1(2h)-phthalazinone derivatives by thionyl chloride 1993 Ingår i: Synthetic Communications. - : Informa UK Limited. - 0039-7911 .- 1532-2432. ; 23:21, s. 2957-2964 Tidskriftsartikel (refereegranskat)abstract cis-4a, 5, 6, 7, 8, 8a-Hexahydro-4-phenyl-l(2H)-phthalazinones (2) react with thionyl chloride in benzene to give tetrahydro derivatives (3); the corresponding reaction of methylene bridged derivatives (5) is also described.
5.	Csende, F., et al. (författare) Synthesis and structural study of new saturated isoindol-1-one derivatives 1993 Ingår i: Heterocycles. - : The Japan Institute of Heterocyclic Chemistry. - 0385-5414 .- 1881-0942. ; 36:8, s. 1809-1821 Tidskriftsartikel (refereegranskat)abstract Condensation of 2-p-toluoylcyclohexanecarboxylic acid (1a,b) with primary amines gave the corresponding hexahydroisoindol-1-ones (2a-g) in good yield. The octahydro derivatives (4a-g) were prepared from cis- and trans-hexahydro-1(2H)-phthalazinone (3a,b) by reduction with zinc-hydrochloric acid via ring contraction. Stereoselective synthesis of cis-N-phenyloctahydroisoindol-1-one (4h) was performed starting from 2b by reduction with magnesium-methanol at room temperature. Configurational assignments of cis and trans isomers were based on 1H-and 13C-nmr spectroscopic studies.
6.	Csende, F., et al. (författare) Synthesis and structural study of novel 1,2-diazepinones and azabicyclooctane derivatives 1996 Ingår i: Heterocyclic Communications. - : Walter de Gruyter GmbH. - 0793-0283 .- 2191-0197. ; 2:5, s. 453-461 Tidskriftsartikel (refereegranskat)abstract Condensation of 3-toluoyl-1,2,2-trimethylcyclopentane-1-carboxylic acid 2 with hydrazine, diamines or 3-aminopropanol afforded the novel bicyclic 1,2-diazepinone 3 or various condensed azabicyclooctane derivatives 4-6, respectively. Further transformations of the 1,2-diazepinone 3 to its perhydro 7 and N-methyl 8 derivatives are also described. Compound 3 when treated with Zn/HC1 resulted in the azabicyclo[3.2.1] octanone derivative 9 by a stereoselective ring contraction. Lactone formation from 3 on treatment with acetic anhydride has also been attempted.
7.	Cziáky, Z., et al. (författare) Synthesis of 2H‐pyrano[2,3‐b]quinolines. Part II. Preparation and 1H‐nmr investigations of 4‐hydroxy‐2‐methyl‐3,4‐dihydro‐2H‐pyrano[2,3‐b]quinolines 1995 Ingår i: Journal of Heterocyclic Chemistry. - : Wiley. - 0022-152X .- 1943-5193. ; 32:3, s. 755-760 Tidskriftsartikel (refereegranskat)abstract Diastereoisomers of 4‐hydroxy‐2‐methyl‐3,4‐dihydro‐2H‐pyrano[2,3‐b]quinolines 8 and 9 were synthesized starting from the appropriate 2‐chloroquinoline‐3‐carboxaldehydes 1. The relative configuration of the 1,3‐diol intermediates 4 and 5 was determined on the basis of the 13C‐nmr spectra of their acetonides. The relative stereochemistry of title compounds was confirmed by using homonuclear NOE and selective decoupling experiments, as well as by analysis of the coupling patterns observed in their 1H‐nmr spectra.
8.	Farkas, I., et al. (författare) Crystal structure of the sodium salt of the uranyl-oxyacetate-fluoride dimer, Na4(UO2)2(OCH2COO)2F 4 · 6H2O 1999 Ingår i: Acta Chemica Scandinavica. - : Danish Chemical Society. - 0904-213X .- 1902-3103. ; 53:11, s. 1009-1012 Tidskriftsartikel (refereegranskat)abstract The structure of the ternary uranyl-oxyacetate-fluoride dimer, (UO2)2(OCH2COO)2F4 4-, was studied by single crystal X-ray diffraction. The space group is P1̄, and the structure contains discrete dimers with a double pentagonal bipyramid geometry, linked by octahedrally coordinated sodium ions. The uranyl ion has a coordination number of five with two fluorides and three oxygens coordinated in a plane perpendicular to the linear UO2 axis. The dimer is formed via bridging oxygen atoms from the deprotonated hydroxyl groups of the glycolate ligands.
9.	Kálai, T., et al. (författare) Synthesis and reactions of new nitronyl nitroxides 1997 Ingår i: Synthesis (Stuttgart). - : Georg Thieme Verlag KG. - 0039-7881 .- 1437-210X. ; 1997:09, s. 1049-1055 Tidskriftsartikel (refereegranskat)abstract Various new 2-substituted 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-yloxyl 3-oxide mono- 1b, 7, 13a,b, 14, 15, 16, 17, 22 and biradicals 8, 9 were prepared. The nitronyl nitroxide functions were selectively reduced by Fe/HOAc to 1-hydroxyimidazoline derivatives 3b, 11, 21. The reductions by Zn/HCl led to imidazolines 4, 12. The nitronyl nitroxide functions remained inert when the 2-phenyl compound was nitrated by H2SO4/HNO3 to give nitrophenyl nitronyl nitroxide derivatives 13a,b, 14.
10.	Kálai, T., et al. (författare) Synthesis of 2-(2-thienyl)benzimidazoles by the reaction of 2- (mercaptomethyl)benzimidazole with β-electrophilic esters 1997 Ingår i: Synthetic Communications. - : Informa UK Limited. - 0039-7911 .- 1532-2432. ; 27:12, s. 2041-2050 Tidskriftsartikel (refereegranskat)abstract New 2-(2-di- and tetrahydrothienyl)benzimidazole compounds were prepared by the ring closure reactions of 2-(mercaptomethyl)benzimidazole (1) and α,β-unsaturated compounds activated with electron-withdrawing groups.
11.	Kalai, T., et al. (författare) Synthesis of new allylic mtroxides via the wadsworth-emmons reaction 1996 Ingår i: Organic preparations and procedures international. - : Informa UK Limited. - 0030-4948 .- 1945-5453. ; 28:4, s. 443-452 Tidskriftsartikel (refereegranskat)
12.	Kćrćdi, F., et al. (författare) Fused 1,2,4-triazole heterocycles. ii : Reaction of 2-chloro-3-(1,3-dioxolan-2-yl)quinolines with 1,2,4-triazole-5-thiol 1995 Ingår i: Heterocyclic Communications. - : Walter de Gruyter GmbH. - 0793-0283 .- 2191-0197. ; 1:2-3, s. 195-198 Tidskriftsartikel (refereegranskat)abstract Reaction of 2-chloro-3-(1,3-dioxolan-2-yl)quinolines 1 with 1,2,4-triazole-5-thiol 2 leads to the formation of a mixture of 11-(2-hydroxyethyl)oxy-11H-[1,2,4]triazolo[5',1':2,3][1,3]thiazino[6,5-b]quinolines 3 and 11-(2-hydroxyethyl)oxy-11/-/-[1,2,4]triazolo[3',4':2,3][1,3]thiazino[6,5-£>]quinolines 4. The structures of the separated regioisomers were determined by homonuclear NOE difference spectroscopy and the results were further confirmed by desulfurisation.
13.	Kóródi, F., et al. (författare) Fused 1,2,4-TriazoIe Heterocycles. IV. Synthesis of Four New Heterocyclic Ring Systems of [1,2,4]Triazolo[1,3]thiazinoquinolines 1997 Ingår i: Journal of Heterocyclic Chemistry. - : Wiley. - 0022-152X .- 1943-5193. ; 34:4, s. 1275-1281 Tidskriftsartikel (refereegranskat)abstract Syntheses of 5H-[1,2,4]triazolo[5′1′:2,3][1,3]thiazino[5,4-c]quinolines 8, 5H-[1,2,4]triazolo[3′,4′:2,3][1,3]thiazino[5,4-c]quinolines 9, 5H-[1,2,4]triazolo[5′1′:2,3][1,3]thiazino[5,6-c]quinolines 14 and 5H-[1,2,4]triazolo[3′,4′:2,3][1,3]thiazino[5,6-c]quinolines 15 are described starting from 4-chloro-3-chloromethylquinaldine (4) and 1,2,4-triazole-5-thiols 5 taking advantage of different reactivity of the chlorine atoms of 4 under different reaction conditions. The structures of products 8, 9, 14 and 15 and the intermediates leading to them were confirmed by desulfurization, unequivocal syntheses and nmr spectroscopy as well.
14.	Kóródi, F., et al. (författare) Fused 1,2,4-triazole heterocycles. I. Synthesis of novel [1,2,4]triazolo[5′,1′:2,3][1,3]thiazino[6,5-b]quinolines 1992 Ingår i: Heterocycles. - : The Japan Institute of Heterocyclic Chemistry. - 0385-5414 .- 1881-0942. ; 34:9, s. 1711-1720 Tidskriftsartikel (refereegranskat)abstract Derivatives of a new heterocyclic ring system of [1,2,4]triazolo[5′,1′: 2,3][1,3]thiazino[6,5-b]quinolines (4,5,6,7 and 8) have been synthesised by the reaction of 2-chloroquinoline-3-carbaldehyde derivatives (1 and 2) with 1,2,4-triazole-5-thiols (3), and subsequent transformations of the hydroxy group of 11-hydroxy[1,2,4]triazolo[5′,1′: 2,3][1,3]thiazino[6,5-b]quinoline (4a).
15.	Kóródi, F., et al. (författare) Fused 1,2,4-triazole heterocycles. iii. syntheses and structures of novel [1,2,4]triazolo[1,3]thiazinoquinolines 1995 Ingår i: Heterocyclic Communications. - : Walter de Gruyter GmbH. - 0793-0283 .- 2191-0197. ; 1:4, s. 297-306 Tidskriftsartikel (refereegranskat)abstract Synthetic methods are described for the preparation of 5H-[1,2,4]triazolo[5‘,1’:2,3][1,3]thiazino[4,5-b]quinolines 5, 5H-[1,2,4]triazolo[3',4’:2,3][1,3]thiazino[4,5-b]quinolines 6, 11 H-[1,2,4]triazolo[5‘, 1 ':2,3][1,3]thiazino[6,5-b]quinoline 13 and 11H-[1,2,4]triazolot[3',4’:2,3][1,3]thiazino[6,5-b]quinoline 14 starting from 2-chloro-3-chloromethylquinoline 1 and 1,2,4-triazole-5-thiols 2. Different reactivity of the chlorine atoms of 1 under different reaction conditions, and a new rearrangement were observed during elaboration of these methods. The structures of the products 5, 6,13,14 and the intermediates leading to them were confirmed by desulfurisation reactions, unequivocal syntheses and nmr spectroscopy.
16.	Lévai, A., et al. (författare) Synthesis of 3-acyl-4-aryl-2-pyrazolines by the reaction of α,β-unsaturated ketones with diazomethane 1996 Ingår i: Indian journal of chemistry. Section B. - 0376-4699 .- 0975-0983. ; 35:10, s. 1091-1096 Tidskriftsartikel (refereegranskat)abstract 3-Acyl-4-aryl-2-pyrazolines 32-62 have been synthesized by the reaction of α,β- unsaturated ketones 1-31 with diazomethane, The hitherto unknown glycoside acetates 47-52 of some 2-pyrazolines and 4-[3-(2- chloro)quinolinyl]-2- pyrazolines 53-62 have also been prepared.
17.	Levai, A., et al. (författare) Synthesis of exocyclic α,β-unsaturated ketones 1992 Ingår i: Pharmazie. - 0031-7144. ; 47:1, s. 56-57 Tidskriftsartikel (refereegranskat)
18.	Liu, Tianqi, et al. (författare) Bioinspired Active Site with a Coordination-Adaptive Organosulfonate Ligand for Catalytic Water Oxidation at Neutral pH 2023 Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 145:21, s. 11818-11828 Tidskriftsartikel (refereegranskat)abstract Many enzymes use adaptive frameworks to preorganize substrates, accommodate various structural and electronic demands of intermediates, and accelerate related catalysis. Inspired by biological systems, a Ru-based molecular water oxidation catalyst containing a configurationally labile ligand [2,2′:6′,2″-terpyridine]-6,6″-disulfonate was designed to mimic enzymatic framework, in which the sulfonate coordination is highly flexible and functions as both an electron donor to stabilize high-valent Ru and a proton acceptor to accelerate water dissociation, thus boosting the catalytic water oxidation performance thermodynamically and kinetically. The combination of single-crystal X-ray analysis, various temperature NMR, electrochemical techniques, and DFT calculations was utilized to investigate the fundamental role of the self-adaptive ligand, demonstrating that the on-demand configurational changes give rise to fast catalytic kinetics with a turnover frequency (TOF) over 2000 s–1, which is compared to oxygen-evolving complex (OEC) in natural photosynthesis.
19.	Marton, J., et al. (författare) Herstellung von 6,14‐Ethenomorphinan‐Derivaten 1993 Ingår i: Liebigs Annalen der Chemie. - : Wiley. - 0170-2041 .- 1099-0690. ; 1993:8, s. 915-919 Tidskriftsartikel (refereegranskat)abstract Preparation of 6,14‐Ethenomorphinane Derivatives Buprenorphine (5j) and diprenorphine (5k) were synthesized from N‐formyl‐northebaine (1c) and N‐benzyl‐northebaine (1d) via new intermediates. N‐cyclopropylmethyl‐dihydronorthevinone 3d is a suitable compound for the synthesis of both 5j and 5k. We carried out detailed 1H‐ and 13C‐NMR analysis of the new compounds.
20.	Marton, J., et al. (författare) Isomerization reactions of 7-substituted 6,14-bridged thebaine derivatives (Bentley compounds) 1998 Ingår i: Acta Chemica Scandinavica. - : Danish Chemical Society. - 0904-213X .- 1902-3103. ; 52:10, s. 1234-1238 Tidskriftsartikel (refereegranskat)abstract Equilibration of the 7α→7β isomers of 7-subslituted 6,14-ethenomorphinanes has been accomplished, for the first time, in dipolar aprotic solvents by the application of bases with weak nucleophilic character. Transformation of the 7β-nitrile with phenylmagnesium bromide led to a new type of 6,6′-dimeric compound.
21.	Marton, J., et al. (författare) New nepenthone and thevinone derivatives 1997 Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 5:2, s. 369-382 Tidskriftsartikel (refereegranskat)abstract The diastereoselective reaction of thevinone (2a) and nepenthone (2c) and their dihydro derivatives (2b and d) with Grignard reagents afforded new N-substituted (20S)- and (20R)-phenyI-6,14-ethenomorphinan derivatives (6a-y). The Grignard reaction of the N-substituted-N-demethyl derivatives 4a-f and 4m-r with methylmagnesium iodide resulted in the (20R)-phenyl tertiary alcohols 5a-f and 5m-r, respectively, but the conversion of 4g-l and that of the N-substituted-dihydrothevinone derivatives with phenylmagnesium bromide afforded the (20S)-phenyl derivatives 5g-l and 5s-y, respectively. The N-cyclopropylmethyl-, N-β-phenylethyl-, and N-propyl derivatives were prepared by the 3-O-demethylation of compounds 5. For the synthesis of the N-allyl-, N-dimethylallyl-, and N-propargyl compounds 2a-d were reacted with the corresponding Grignard reagent, and treatment of the products with cyanogen bromide gave the cyanamides 8a-d. These latter compounds were transformed into 10a,b,d, whose alkylation led to the target derivatives 6d-f, j-l, p-r, and w-y. The biochemical investigation of these substances showed that the affinities to the δ-opioid receptors were high, but the selectivity was low. Tn two cases (6c and 11d) a μ-opioid receptor specificity was observed.
22.	Marton, J., et al. (författare) Reaction of morphinan-6,8-dienes with azadienophiles 1996 Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 52:7, s. 2449-2464 Tidskriftsartikel (refereegranskat)abstract Reaction of various morphinan dienes, i.e. thebaine (1a), N-demethyl-N-formylthebaine (1b), 6-demethoxythebaine (1c), β-dihydrothebaine (2a), 4-acetoxy-β-dihydrothebaine (2b), 7-chloro-6-demethoxythebaine (3a) and 7-bromo-6-demethyoxythebaine (3b) with 4-phenyl-4H-1,2,4-triazoline-3,5-dione (PTAD) gave rise to new Diels-Alder (DA) adducts. DA-reaction of 1a, 1b and 1c with PTAD led to the products of the β-face attack of the dienophile at the diene unit. The W coupling (4J(5β,18)) in the 1H-NMR spectra was indicative of these structures. α-Face addition took place in the case of morphinan dienes with opened ring E, and a by-product was formed due to the S(E) reaction of PTAD with the adducts. The structure of these derivatives was confirmed by means of NMR spectroscopic methods. The retro Diels-Alder (rDA) reaction of the adducts 4a and 4b readily took place in polar-aprotic solvents in the presence of bases with low nucleophilic character.
23.	Marton, J., et al. (författare) Studies on the synthesis of β-thevinone derivatives 1998 Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 54:31, s. 9143-9152 Tidskriftsartikel (refereegranskat)abstract The reactions of β-thevinone and β-dihydrothevinone with tert- butylmagnesium chloride and n-propylmagnesium bromide were investigated. Further chemical transformations (N-demethylation, N-alkylation, O- demethylation) of the tertiary alcohols afforded the known β-buprenorphine and the hitherto unknown β-etorphine and β-dihydroetorphine. The by- products of these reactions were also isolated, their structures identified, and the mode of their formation was explained.
24.	Micskei, K., et al. (författare) Reactions of nepenthone with chromium(II) reagents in neutral aqueous medium 1999 Ingår i: European Journal of Organic Chemistry. - : Wiley. - 1434-193X .- 1099-0690. ; :1, s. 149-153 Tidskriftsartikel (refereegranskat)abstract A synthetic method for the selective transformations of a selected morphine alkaloid in neutral aqueous medium is introduced. Full diastereoselectivity was achieved by the transformation of nepenthone (1) with [Cr(ida)(H2O)3] into 2a (20R) showing a complementary method as compared to the reactions with classical reagents to result in 2b (20S). A new unexpected morphine derivative 3 was prepared by a ligand-induced modification of the reaction which involves an unprecedented rearrangement.
25.	Proietti, Giampiero, et al. (författare) Ultralight aerogels via supramolecular polymerization of a new chiral perfluoropyridin-based sulfonimidamide organogelator Annan publikation (övrigt vetenskapligt/konstnärligt)
26.	Proietti, Giampiero, et al. (författare) Ultralight aerogels via supramolecular polymerization of a new chiral perfluoropyridine-based sulfonimidamide organogelator 2024 Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 16:15, s. 7603-7611 Tidskriftsartikel (refereegranskat)abstract Chiral and enantiopure perfluorinated sulfonimidamides act as low-molecular weight gelators at low critical gelation concentration (<1 mg mL-1) via supramolecular polymerization in nonpolar organic solvents and more heterogenic mixtures, such as biodiesel and oil. Freeze-drying of the organogel leads to ultralight aerogel with extremely low density (1 mg mL-1). The gelation is driven by hydrogen bonding resulting in a helical molecular ordering and unique fibre assemblies as confirmed by scanning electron microscopy, CD spectroscopy, and computational modeling of the supramolecular structure.
27.	Repasi, J., et al. (författare) 5'-O-demethylnarcotine : A new alkaloid from Papaver somniferum 1993 Ingår i: Planta Medica. - : Georg Thieme Verlag KG. - 0032-0943 .- 1439-0221. ; 59:5, s. 477-478 Tidskriftsartikel (refereegranskat)
28.	Somogyi, L., et al. (författare) Synthesis and stereostructure of some spiro[morphinan‐6,2′(3′H)‐[1,3,4]oxa(thia)diazolines] 1995 Ingår i: Liebigs Annalen. - : Wiley. - 0947-3440 .- 1099-0690. ; 1995:7, s. 1393-1395 Tidskriftsartikel (refereegranskat)abstract Treatment of dihydrocodeinone (thio)semicarbazones 1a–d with Ac2O/ZnCl2 afforded (6S)‐spiro[morphinan‐6,2′(3′H)‐[1,3,4]oxadiazolines] 2a, b and (6R)‐spiro[morphinan‐6,2′‐(3′H)‐[1,3,4]thiadiazolines] 3a, b, respectively. The structure of the products including the configuration of the spiro carbons was determined by 1H‐ and 13C‐NMR measurements.
29.	Szabo, Zoltan, Associate professor, et al. (författare) 1H and 13C NMR study of novel fused 1,2,4‐triazole heterocycles 1992 Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 30:11, s. 1111-1116 Tidskriftsartikel (refereegranskat)abstract The 1H and 13C NMR spectra of some novel 1,2,4‐triazolo [1,3] thiazinoquinoline isomeric pairs are interpreted in terms of structural assignments. The structure of most compounds has been confirmed by NOE difference spectroscopy. Characteristic differences have been observed in both 1H and 13C NMR spectra of these isomeric Pairs: some of the 1H and 13C chemical shifts, and also the one bond 13C1H couplings of triazole protons, differ consistently in the NMR spectra of the isomers. The coupling constants have been determined using a combination of INEPT and chemical shift selective filtering.
30.	Szabó, Zoltan, Associate professor, et al. (författare) Application of 19F NMR spectroscopy to the study of equilibrium dynamics of uranyl(2+)‐fluoride complexes 1995 Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 33:1, s. 20-26 Tidskriftsartikel (refereegranskat)abstract One‐ and two‐dimensional magnetization‐transfer 19F NMR methods were applied in a quantitative study of the fluoride exchange for uranyl(2+)‐fluoride complexes in aqueous solution. The applicability of these techniques and the classical lineshape analysis is discussed, and the quality of the results (rate constants and relaxation rates) obtained by the three methods is compared.
31.	Szabó, Zoltan, Associate professor, et al. (författare) Conformational studies on B/C‐cis‐ and B/C‐trans‐morphinan derivatives 1995 Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 33:11, s. 913-916 Tidskriftsartikel (refereegranskat)abstract An unambiguous structural differentiation of B/C‐cis‐ and B/C‐trans‐morphinan derivatives (thebainone‐A and β‐thebainone‐A and their 7,8‐dihydro derivatives) is provided. The structures were confirmed by NOE difference spectroscopy and selective 2D J‐INEPT experiments. In addition, full a priori 1H and 13C NMR assignments of the isomeric pairs studied are presented.
32.	Szabó, Zoltan, Associate professor, et al. (författare) Interpretation of the 13C NMR spectra of 3‐benzylideneflavanones, 3‐benzylflavone and 3‐benzyl‐1‐thioflavone derivatives 1993 Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 31:4, s. 418-421 Tidskriftsartikel (refereegranskat)abstract 13C NMR spectra of 3‐benzylflavones, 3‐benzylideneflavanones, 3‐benzyl‐4‐thioflavones, 3‐benzyl‐1‐thioflavones, 3‐benzyl‐1,4‐dithioflavones and 3‐benzyl‐1‐thioflavone‐1,1‐dioxides were analysed and correlated to evaluate the consequences of the replacement of oxygen with sulphur.
33.	Szabó, Zoltan, Associate professor, et al. (författare) Kinetics of Ligand Exchange Reactions for Uranyl(2+) Fluoride Complexes in Aqueous Solution 1996 Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 35:7, s. 2036-2044 Tidskriftsartikel (refereegranskat)abstract Rates and mechanisms of fluoride exchange reactions between various uranyl fluoro complexes {UO2(H2O)5-nFn2-n}, and HF/F- have been studied in aqueous solution using 19F and 17O NMR line broadening technique. A group of 15 different exchange pathways has been identified, and their rate laws and rate constants have been determined. All reactions are first order with regard to the uranyl complex and second order overall. Two pathways dominate: fluoride exchange between two uranyl complexes, presumably through the formation of a fluoride bridging intermediate/transition state, e.g., UO2F+ + UO2F2 ⇄ UO2FF + UO2F+ (k1,2), and fluoride exchange between a uranyl complex and F-/HF, e.g., UO2F+ + HF ⇄ UO2F+ + HF (k1,HF). The exchange between UO22+ and UO2F+ takes place mainly according to UO22+ + HF ⇄ UO2F+ + H+ (forward, k′O,HF; reverse, k1,HF). Most of these reactions have rate constants, km,n ≈ 5 × 104 M-1 s-1, at -5 °C. The exchange reactions seem to follow the Eigen - Wilkins mechanism, where the rate determining step is a ligand promoted dissociation of coordinated water. The exchanges involving UC2Fn2-n, n = 4 and 5, are much faster than the others, indicating mechanistic differences. The exchange rate was approximately 3 times faster for reactions involving DF than for HF. The activation parameters have been determined for two reaction pathways.
34.	Szabó, Zoltan, Associate professor, et al. (författare) Mechanisms of Ligand Substitution Reactions in Ternary Dioxouranium(VI) Complexes 1998 Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 37:24, s. 6214-6221 Tidskriftsartikel (refereegranskat)abstract The activation parameters of various inter- and intramolecular ligand exchange reactions in ternary complexes of the type UO2LF3 (where L is one of the bidentate ligands picolinate, 4-nitropicolinate, 4-(3-pentyl)picolinate, oxalate, or carbonate) and UO2L2F (where L = picolinate or oxalate) have been determined by different NMR techniques. The activation entropies for the reactions have been used to discuss their intimate mechanism, particularly the solvent participation. Additional mechanistic information has been obtained from studies of H+/ D+ catalysis of the various reactions. Through the use of the proton-catalyzed pathway, the rate of carbonate exchange in UO2CO3F33- was varied by a factor of ca. 10. The fact that the rate of fluoride exchange remained constant clearly indicates that the exchanges of carbonate and fluoride follow parallel pathways. The activation entropies of most of the fluoride exchange reactions in UO2LF3 have values close to 10 J K-1 mol-1, indicating dissociative (D) or dissociative interchange (ID) mechanisms. The exchange of L takes place in two steps: The first is a chelate ring opening/closing, resulting in a ligand rotation. The second is bond breaking at the carboxylate end and exchange; hence, the activation entropies for the exchange vary with L. In the 4-nitropicolinate and carbonate systems, where the exchange of L is faster than that of F-, the exchange takes place in a dissociative reaction via the intermediate/transition state "UO2F3", which contains a lower number of coordinated water molecules than that of UO2(H2O)2F3-. There is no evidence of the presence of unidentate L at equilibrium, indicating that the equilibrium constant for the ring opening, K = k1/k-1, is smaller than 0.05. Hence, the observed rate constant for the ligand rotation is approximately equal to that for the ring opening whereas that of the ring closing is at least 20 times larger. The activation entropies for these reactions indicate a much smaller involvement of water in the activated state in the 4-nitropicolinate complex than those of the other two picolinates, a signature of reactions of ID mechanisms. The exchange of fluoride and oxalate in UO2(oxalate)2F3- is first-order with respect to the concentration of the complex and independent of the concentrations of free fluoride and oxalate. The fact that the exchange of oxalate is independent of the free oxalate concentration but still slower than that of fluoride shows that they take place along separate pathways and not as consecutive reactions along the fluoride exchange pathway. The exchange reactions have nearly the same activation parameters whereas those for the fluoride exchange change significantly between H2O and D2O. This together with the negative activation entropy, -74 J K-1 mol-1, indicates solvent participation in the activated state, presumably an ID mechanism with extensive solvation of the leaving fluoride. All ligand exchange reactions are proton-catalyzed with a reverse-isotope effect, indicating the formation of a protonated precursor. The exchange reactions also are catalyzed to a small extent by hydrofluoric and acetic acids, which act as proton donors, without the involvement of the conjugate bases in the exchange reactions. These reactions have normal isotope effects.
35.	Szabó, Zoltan, Associate professor, et al. (författare) Structure, Isomerism, and Ligand Dynamics in Dioxouranium(VI) Complexes 1997 Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 36:23, s. 5369-5375 Tidskriftsartikel (refereegranskat)abstract The ligand exchange reactions in complexes of the type UO2LFn(H2O)3-n, where n = 1-3 and L is one of the bidentate ligands picolinate (pic), oxalate (ox), carbonate, and acetate (ac), UO2L2F (L = picolinate or oxalate), have been investigated by using an array of 19F-, 13C-, 17O-, and 1H-NMR techniques. The rates of exchange were sufficiently low to allow the identification of isomers, which are those expected for a pentagonal bipyramid coordination geometry, with the "y1" oxygens in the apical positions. All ligand exchange reactions were independent of the concentration of free ligand. Two different fluoride exchange pathways were identified, intermolecular exchange between coordinated and free fluoride and intramolecular exchange between different fluoride sites within a given complex. The intramolecular exchange reaction in UO2(pic)F33- was shown to be a result of opening/closing of the chelate ring, equivalent to a site exchange between the two "edge" fluorides. Dissociation of acetate is the major factor determining the intramolecular fluoride exchange reactions in UO2(ac)F32-. In this same way the broad 19F-NMR peaks for UO2LF2(H2O)2- and UO2LF(H2O)2- are a result of a comparatively slow exchange between coordinated and bulk water. At pH > 6 UO2(ox)F(H2O)2- forms a hydroxide-bridged dimer (UO2)2(ox)2F2(OH)2 4-, which exists in two isomeric forms.
36.	Szabó, Zoltan, Associate professor, et al. (författare) Synthesis and biological activity of 4‐aikoxy‐ and 4‐ω‐aminoalkoxy‐2‐trichloromethylquinolines 1991 Ingår i: Pesticide science. - : Wiley. - 0031-613X .- 1096-9063. ; 31:3, s. 263-271 Tidskriftsartikel (refereegranskat)abstract A number of new 4‐alkoxy‐ and 4‐ω‐aminoalkoxy‐2‐trichloromethyl‐quinolines were synthesised and tested on insects, weeds and plant pathogens. Many of these compounds showed antifungal activity against different fungal species. Some compounds, IVa, IVb, IVc, Vb, Vc and VI, had interesting effects on Phycomycete fungi.
37.	Tóth, I., et al. (författare) Application of a sulphide-selective electrode in the absence of a pH-buffer 1988 Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 35:10, s. 783-788 Tidskriftsartikel (refereegranskat)abstract Calibration of a sulphide electrode in the pH-range 9-12 has been studied as an e.m.f. vs. (pH - p[HS-]) function by measuring e.m.f. and pH in parallel. Calibration can also be done in this pH range by using a differential amplifier with a three-electrode measuring cell (glass, sulphide-selective and reference electrodes). The effects of an antioxidant (ascorbic acid) and a complexing agent (DCTA) on the calibration of the glass-sulphide electrode cell at pH < 5 were studied. The applicability of this end-point indicator cell has been demonstrated for titrations of Ag+, Pb2+ and Bi3+ with Na2S.
38.	Tóth, I., et al. (författare) Extraction of gallium(III) and aluminium(III) with O,O-dialkyldithiophosphoric acids 1990 Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 37:12, s. 1175-1178 Tidskriftsartikel (refereegranskat)abstract The extraction of Ga3+ and Al3+ with the liquid cation-exchangers di-n-butyldithiophosphoric acid (DBTPA) and di-(2-ethylhexyl)dithiophosphoric acid (DETPA) in kerosene, in the presence and absence of alcohols and tri-n-butyl phosphate (TBP) has been studied. Both Ga3+ and Al3+ can be extracted in the form of a neutral complex, MA3, but the distribution coefficient of Ga3+ is the higher by about two orders of magnitude, which can be the basis of the solvent extraction separation of gallium and aluminium. The differences can be explained by the interaction between the sulphur donor atoms of the extractants and the d10 electronic shell of Ga3+ as well as by the lower steric hindrance of ligands co-ordinated to Ga3+.
39.	Toth, I., et al. (författare) STUDIES ON THE EXTRACTION OF GALLIUM AND ALUMINIUM WITH DIALKYL-DITHIOPHOSPHORIC ACIDS. 1986 Ingår i: Reactive polymers. Ion exchangers, sorbents. - : Elsevier BV. - 0167-6989. ; 7:2-3 Tidskriftsartikel (refereegranskat)abstract The extraction of Ga3 plus has been studied with the liquid cation exchangers di-n-butyl-dithiophosphoric acid (DBTPA) and di-(2-ethylhexyl)-dithiophosphoric acid (DETPA) in kerosene. The partition of Ga3 plus and Al3 plus has been studied between equal volumes of aqueous and organic phases. The extraction coefficients obtained with DETPA are about one order of magnitude higher than those obtained with DBTPA. The trend of the extraction coefficients with increasing pH can be interpreted assuming the extraction of species M(DBTPA)//3 and M(DETPA)//3. The extraction coefficients are about two orders of magnitude higher for Ga3 plus than for Al3 plus . The extent of extraction of both Ga3 plus and Al3 plus decreases at higher pH and at pH less than 10 there is practically no extraction.

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