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1.
Six kinds of tetra alkylester type calix[4]arene derivatives, (R1=R2=CH31, C2H52, C3H73,n-C4H94,t-C4H95,n-C10H216), a diethyl-didecyl mixed ester type (R1=C2H5, R2 =C10H217), and three kinds of lower rim bridged types (R1=C2H5, R2–R2=(CH2)108, (CH2)129, (CH2)2(OCH2CH2)310) were characterized by electrochemical measurement to elucidate the effect of the length of the alkyl group of alkoxycarbonyl substituents on Na+ selectivity. To obtain excellent Na+ selective ionophores, introduction of short chain alkyl groups rather than long chain ones, such as a decyl group, and maintenance of sufficient solubility of the calix[4]arene derivatives in the membrane solvent are required concurrently. Among the calix[4]arenes tested, 25,26,27,28-tetrakis[(ethoxycarbonyl)methoxy]-p-tert-butylcalix[4]arene2, and the diethyl-didecyl mixed ester type derivative7 are the best ionophores for a Na+ selective electrode. On the other hand, sodium selectivity of the bridged type derivative9 is comparable or even superior to that of the known bis(12-crown-4).This paper is dedicated to the commemorative issue on the 50th anniversary of calixarenes.  相似文献   

2.
Summary The title compound2 was prepared either by highpressure reaction of 1,1-bianthryl with ethylene or by coupling of 1-bromo-9,10-dihydro-9,10-ethanoanthracene (4). Both syntheses afforded a mixture of diastereoisomers (meso2a and racemate2b) in a ratio of 1.5:1 and 2.3:1, respectively. Configurational assignment was possible both from the1H- and13C-NMR spectra and by coupling of laevorotatory4 (accessibly by enantioselective chromatography on triacetyl cellulose in ethanol) to laevorotatory2b. (+)-4 was tranformed into the dextrorotatory carboxylic acid (+)-5 of known configuration (9R) thus establishing the configuration of (+)-4 as (9R) too and hence the centrochirality in (–)-2b as (9S)(9S). The racemic form2b is a conformational (appr. 1.8:1) mixture of two rotamers.The rotational barrier was established as G #=92–95 kJ mol–1 (depending on the temperature) both by1H-NMR and CD kinetics (based on equilibration of the separated optically active rotamers ofracem.2). For the latter preferred conformations were assumed allowing the assignment of the axial chirality: e.g. (–)-(9S)(R)a(9S) for the main rotamer of (–)-2 b [and (–)(9S)(S)a(9S) for the underpopulated one].All assumptions were confirmed by X-ray crystal structure analyses of2 a and the main rotamer of2b with torsional angles around the 1,1-bonds of –111.1 and –121.2°, respectively.Dedicated to Prof. K. L. Komarek (Vienna) with cordial wishes on the occasion of the 65th anniversary of his birthday  相似文献   

3.
Glaser  Robert  Geresh  Shimona  Luria  Shlomo  Drouin  Marc  Michel  André 《Structural chemistry》1994,5(4):277-282
Hydrogenation ofZ-(–)-(1R, 3R, 4S)-menthyl 2-formamido-4,4,4-trifluoro-2-butenoate catalyzed by Pd/C was performed at atmospheric pressure to yield a mixture of (2R, 1R, 3R, 4S)- and (2S, 1R, 3R, 4S)-menthyl 2-formamido-4,4,4-trifluorobutanoate diastereomers in a 5545 ratio, respectively. Repeated fractional crystallization from ethyl acetate and vapor diffusion of petroleum ether afforded (+)–(2S, 1R, 3R, 4S)-menthyl 2-formamido-4,4,4-trifluorobutanoate as clear colorless, crystalline prisms which were subjected to single-crystal X-ray diffraction analysis. The crystals belong to the orthorhombic system P212121, and at 213 K:a=5.054(1),b= 10.000(2),c=32.707(1) Å,V=1652.9(4) Å3,Z=4,R(F)=0.040, andR w (F)=0.037. The finding of the (2S)-configuration for the formamido-acid portion of the (+)-ester enabled the configurational assignment of the asymmetric hydrogenation products ofZ-methyl 2-formamido-4, 4,4-trifluoro-2-butenoate catalyzed by chiral diphosphine/rhodium(I) complexes.  相似文献   

4.
The Piloyan activation energiesE, as well as the initial exotherm temperaturesT D, are determined for sixN-monoalkyl- and fiveN,N-dialkyl-2,4,6-trinitroanilines. By comparison withR f-factors, orR M-functions of paper chromatography, the molecular-structural dependences ofE andT D are studied for these compounds. Relationships are also found between the termE · T D –1 and theR M-functions. The effects are discussed of the introduction of the 6-nitro group into the TV-substituted 2,4-dinitroanilines, and of the introduction of the 4-nitro group into the 2,6-dinitro analogues, upon the thermal stabilities of the resulting 2,4,6-trinitroanilines.
Zusammenfassung Die AktivierungsenergienE nach Piloyan und die Anfangswerte der ExothermenT D der sechsN-monoalkyl- und fünfN,N-Dialkyl-2,4,6-trinitroaniline wurden bestimmt. Unter Berücksichtigung des Vergleichs mitR f-Faktoren oderR M-Funktionen der Papierchromatographie wurden die molekularstrukturellen AbhÄngigkeiten der WerteE undT D dieser Verbindungen untersucht. ZusammenhÄnge wurden auch zwischen dem AusdruckE · Tw D –1 und denR M-Funktionen gefunden. Der Einfluss der Einführung der 6-Nitrogruppe in dieN-substituierten 2,4-Dinitroaniline, sowie der Einfluss der Einführung der 4-Nitrogruppe in 2,6-Nitroanaloge auf die ThermostabilitÄt der resultierenden 2,4,6-Trinitroaniline werden erörtert.

Résumé On a déterminé les énergies d'activation par la méthode de Piloyan ainsi que les températures initialesT D de l'effet exothermique de sixN-monoalcoyl- et cinqN,N-dialcoyl-2,4,6-trinitroanilines. En se référant aux facteursR F ou aux valeurs des fonctionsR M en Chromatographie sur papier, on a étudié la dépendance entre les valeurs deE et deT D sur les caractéristiques moléculaires-structurales de ces composés.On a également trouvé des rapports entre le termeE · T D –1 et les fonctionsR M. On discute l'influence de l'introduction du groupe 6-nitro dans les 2,4-dinitroanilinesN-substituées ainsi que l'influence de l'introduction du groupe 4-nitro dans les 2,6-dinitro analogues sur la stabilité thermique des 2,4,6-trinitroanilines qui en résultent.

N-- N,N--2,4,6- E , T D. R f,- R M — , - E T D. E.T D –1 R M-. 6N- 2,4- 4 2,6- 2,4,6- .


The authors would like to thank Mrs. Anna Colláková for careful DTA measurements, and Dr. Ladislav Smolka for help in the treatment of the measured results with the Wang 600 computer.  相似文献   

5.
Whereas 1 1 crystalline complexes have been isolated between borane ammonia and methyl 4,6-O-benzylidene-2,3-dideoxy--d-galactopyranosido [2,3-b]-1,4,7,10,13,16-hexaoxacyclo-octadecane (1), methyl 4,6-O-benzylidene-2,3-dideoxy--d-mannopyranosido [2,3-b] (methyl 4,6-O-benzylidene-2,3-dideoxy--d-mannopyranosido [2,3-k]-1,4,7,10,13,16-hexaoxacyclo-octadecane (3), and (1R,2R,7R,24R)-3,5,8,11,14,17,20,23,26,28-decaoxatricyclo-[21.4.0.02,7]octacosane (4), the hosts, methyl, 4,6-O-benzylidene-2,3-dideoxy--d-mannopyranosido[2,3-b] 1,4,7,10,13,16-hexaoxacyclo-octadecane (2) and 1,4 1,4 3,6 3,6-tetra-anhydro-2,2 5,5-bis-O-oxydiethylenedi-d-mannitol (5) have yielded 2 1 (guest:host) crystalline complexes with borane ammonia as guest. X-ray analyses of the supramolecular structures of BH3NH3 ·1, (BH3NH3)2 ·2, BH3NH3 ·3, BH3NH3 ·4, and (BH3NH3)2 ·5 have been carried out and BH3NH3 ·1, BH3NH3 ·2, and (BH3NH3)2 ·5 have been shown to reduce acetophenone with enantiomeric excesses of 5, 13, and 10% respectively. Supplementary Data relating to this article (atomic coordinates of the hydrogen atoms and thermal parameters) are deposited with the British Library as Supplementary Publication No. SUP 82017 (74 pages).Dedicated to Professor H. M. Powell.  相似文献   

6.
Bibasic tetradentateSchiff bases having the donor system OH–NX–NX–OH have been shown to form UO2(NO3)2(SBH2) type of derivatives [SBH2 is the molecule of the bibasic tetradentateSchiff bases such as HOC6H4C(R) N(CH2) n NC(R)C6H4OH (where R=H or CH3 andn=2 or 3) and HOC(R)CHC(CH3)N(CH2) n NC(CH3)CH C(R)OH (where R=CH3 or C6H5 andn=2 or 3)]. The 11 stoichiometry of these complexes is shown by elemental analysis and conductometric titrations. The molar conductence values in nitrobenzene indicate the non-electrolytic behaviour and the magnetic susceptibility measurements by the Gouy method show these complexes to be diamagnetic.With 1 Figure  相似文献   

7.
Yields of n-C4H10 have been measured from the flow pyrolysis of C2H4 at 897 (±7) K. From 77 to 720 Torr the order of n-C4H10 formation was found to be 2.0±0.3 The rate constant for the reaction, was estimated to be 2.4(±0.6)×10–4l mol–1s–1.
-C4H10 C2H4 897 (±7) . -C4H10 77 720 2.0±0.3. 2C2H4C2H3+C2H5 2,4 (±0,6)×10–4 –1–1.
  相似文献   

8.
Zusammenfassung Dihydro-4,4,6-trimethyl-2(1H)-pyrimidinone reagieren mit Formaldehyd und sekundären bzw. primären Aminen zu 6-Dialkylaminoäthylidentetrahydro-2(1H)-pyrimidinonen bzw. Hexahydro-2(1H)-pyrido[4,3-d]Pyrimidinonen. Mit Succindialdehyd bzw. Glutardialdehyd und primären Aminen entstehen 5,7-Äthanohexahydro-2(1H)-pyrido[4,3-d]pyrimidinone bzw. Tetrahydro-6,8-propano-6H-pyrimido[1,6-c]pyrimidin-1(2H)-one. Die 6-Dialkylaminoäthylidentetrahydro-2(1H)-pyrimidinone geben mit Phenolen Tetrahydrospiro([1]benzopyran-2,4(1H)-pyrimidin)-2(3H)-one, mit cycl. -Dicarbonylverbindungen Hexahydrospiro([1]benzopyran-2,4(1H)-pyrimidin)-2,5(3H, 6H)-dione bzw. Tetrahydrospiro(2H,5H-pyrano[3,2-c][1]benzopyran-2,4(1H)-pyrimidin)-2(3H),5-dione bzw. mit Malonestern -(Tetrahydro-4,4-dimethyl-2-oxo-6-pyrimidyl)-äthylmalonester.Zusammenfassung Dihydro-4.4.6-trimethyl-2(1H)-pyrimidinones react with formaldehyde and sec. and prim. amines resp. to 6-dialkylaminoethylidentetrahydro-2(1H)-pyrimidinones and hexahydro-2(1H)-pyrido[4.3-d]pyrimidinones, resp. succindialdehyde and glutaraldehyde with primary amines give 5.7-ethanohexahydro-2(1H)-pyrido[4.3-d]pyrimidinones and tetrahydro6.8-propano-6H-pyrimido[1.6-c]pyrimidin-1(2H)-ones, resp. 6-Dialkylaminoethylidentetrahydro-2(1H)-pyrimidinones react with phenols to tetrahydrospiro([1]benzopyran-2.4(1H)-pyrimidin)-2(3H)-ones, with cyclic -dicarbonyl compounds to hexahydrospiro([1]benzopyran-2.4 (1H)-pyrimidin)-2,5 (3H), 6H)-diones and tetrahydrospiro(2H,5H-pyrano[3.2-c][1]benzopyran-2.4(1H)-pyrimidin)-2(3H),5-diones, resp., with malonates -(tetrahydro-4.4-dimethyl-2-oxopyrimidyl-6)-ethylmalonates.
Mannich reaction with dihydro-6-methyl-2(1H)-pyrimidinones

Herrn Prof. Dr.F. Kuffner zum 65. Geburtstag gewidmet.  相似文献   

9.
Zusammenfassung Die Infrarot- und die Raman-Spektren der Silylamine (CH3)3Si–NH–R (R=CH3, C2H5 und C6H5) sowie der analogen N-deuterierten Verbindungen werden mitgeteilt und analysiert. Starke Kopplungen führen zu einer Mischung vonv SiN bei etwa 700 cm–1 mit anderen Schwingungen des C3Si–NHR-Skelettes.
The Infrared and Raman spectra of the silylamino compounds (CH3)3Si–NH–R (R=CH3, C2H5, and C6H5) and the analogous N-deuterated species are reported and assigned. The SiN stretching mode at about 700 cm–1 is strongly coupled with other vibrations of the molecules.
  相似文献   

10.
The reaction of Pb(OCOCF3)4 with several olefines and conjugated dienes is reported. The oxidation of styrene, stilbene and 1.4-dihydro-1.4-methanonaphthalene leads to phenylacetaldehyde (1), benzaldehyde (2) and benzophenone (3), and to 1.2.3.4-tetrahydro-1.4-methanonaphthalene-(2S,9R+2R,9S)-diol-bis-trifluoroacetate (8) respectively. Of the conjugated dienes, 1.3-cyclohexadiene yieldscis-2-cyclohexene-1.4-diol bis-trifluoroacetate (4), cyclopentadiene yieldscis-2-cyclopentene-1.4-diolbis-trifluoroacetate (5) andtrans-2-cyclopentene-1.4-diol-bis-trifluoroacetate (6) andE,E-2.4-hexadiene yields the isomers of 3-hexene-2.5-diol bis trifluoroacetate (7). Oxidation of unsaturated steroids such as 2-cholestene, 2-androsten-17-one, 4-cholestene, androsta-4.9(11)-diene-3.17-dione and 3-acetoxy-5-cholestene results in cholestane-2,3-diol diacetate (9), 2,3-diacetoxyandrostan-17-one (10) and 1-acetoxy-2-androsten-17-one (11), in coprostane-4,5-diol-4-trifluoroacetate (12) or coprostane 4,5-diol-4-acetate (12a), 4-cholestanone (13), in 12-trifluoroacetoxyandrosta-4,9(11)-diene-3.17-dione (14), and in cholestane-3,5,6-triol-3-acetate-6-trifluoracetate.

Mit 1 Abbildung  相似文献   

11.
The vertical valence ionization potentials of cyclopropane, ethylene oxide and ethylene imine are calculated by a many-body Green's function method. For C3H6 the ordering of the ionization potentials is 2e(), 1e(), 2a1(), 1a2(), 1e(). The assignment of the 2a1 and the 1a2 ionization potentials which has been controversial is thus clarified. The ordering is in agreement with the result obtained via Koopmans' theorem. For ethylene oxide and ethylene imine Koopmans' theorem fails in predicting the correct order of ionic states. For C2H4O the ordering of the ionization potentials is 2b 1(), 4a 1, 1a 2(), 2b 2,3a 1, 1b 1(), 1b 2, 2a 1 and for C2H5N 6a, 5a, 3a, 2a, 4a, 3a, 1a, 2a. The agreement of the computed ionization potentials with the experimental values is very satisfactory.  相似文献   

12.
Developing the previously tested approach to the configurational and conformational analysis of cyclic chiral compounds based on a complex use of NMR spectra and molecular simulation, we determined the configuration 1R, 2R, 4R, 1S and conformational state of 2[1hydroxy1(4carbomethoxyphenyl) methyl]pmenthane3one, a minor product of the directed aldol reaction of (–)menthone with 4carbomethoxybenzaldehyde. The configurations of the cyclic chiral centers were determined by analysis of the spin–spin coupling constants of the protons of the cyclohexanone ring for the most probable conformations of alternative stereoisomers. The S configuration of the C (1) exocyclic chiral center was established from the different orientation of the benzene ring relative to the cyclohexanone fragment in alternative stereoisomers, as shown by semiempirical quantumchemical simulations (AM1 and PM3 methods), and from the observed difference in proton chemical shift between the examined hydroxyketone and the model (+)isomenthone (1R, 4Rdiastereomer).  相似文献   

13.
    
- (I) (III) -- (40–60% .) H2SO4 W3=k3·[I]·[II]. (I). k1 k2 k3 : 1gk1=–3, 36–1, 11·Ho; 1gk 2 =–2, 84–1, 11·Ho; 1gk3=–2, 35–1, 32·Ho. 10,7; 27,8; 23,8 /, .
The Prins reaction of acetaldehyde (III) with -methylstyrene (I) in 40:60 vol. % water-dioxan in the presence of H2SO4 obeys the rate law W3-k3[I] [II]. In addition to the Prins reaction I undergoes both hydration and dimerization. The rate constants for hydration (k1), dimerization (k2) and for the Prins reaction (k3) depend on the acidity of the medium: lg k1=–3.36–1. 11Ho. lg k2=–2.84–1. 11 Ho. lg k3=2.35–1. 32 Ho. The experimental activation energies are 10.7, 27,8 and 23.8 kcal/mol, respectively.
  相似文献   

14.
    
A higher activity of Na–X than Na–Y in CH3SH+SO2 reaction at 343 was observed. The increase of the copper content in the samples causes an increase of their activity. Water, sulfur, dimethyl disulfide, dimethyl trisulfide and sometimes dimethyl sulfide are registered as reaction products. (CH3)2S3 is formed as a result of the reaction between sulfur and (CH3)2S2.
, Na–X , Na–Y CH3SH+SO2 343 . . , , , , . (CH3)2S2 (CH3)2S3.
  相似文献   

15.
Summary The -allylmolybdenum(II) complexes [MoX(CO)2-(NCMe)2(3-C3H4R)] (X=Cl, Br and I; R=H and 2-Me) react either in dichloromethane or acetonitrile with thiosemicarbazones to give the new complexes [MoX-(CO)2(RRCNNHCSNH2)(3-C3H4R)] (R=H or Me; R'=Me, Et, Pr or Ph)via displacement of acetonitrile ligands.  相似文献   

16.
Three polyhydroxylated steroids were isolated from the Far-Eastern starfish Hippasteria phrygiana collected from the Sea of Okhotsk and were characterized as a new glycoside phrygioside A, viz., sodium (20R, 24S)-3,4,7,8,15,24-hexahydroxy-24-O-[3-O-methyl--D-xylopyranosyl-(12)--L-arabinofuranosyl]-5-cholestan-6-yl sulfate, its aglycone, and the already known marthasterone sulfate.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2526–2529, November, 2004.  相似文献   

17.
The parent material, ammonium permanganate, was carefully decomposed in air at 120°. The product, referred to as the starting material (SM), was then subjected to thermal treatment in air for 5 hr in the temperature range 150–1200°. Chemical analysis of SM indicated that the main decomposition product of NH4MnO4 was Mn2O3, together with MnO2, NH4NO3, H2O and O2. Mn3O4 started to form at 900°. The infrared spectra of various calcination products revealed the retention of NH 4 + in the lattice structure up to 300°, and reflected the presence of excess oxygen as coordinated O 2 . The TG, DTA and IRA results on SM supported the chemical analysis data. X-ray analysis was carried out for phase identification and to follow transformations and the formation of a solid solution between MnO2 and Mn2O3.
Zusammenfassung Die Muttersubstanz, Aramoniumpermanganat, wurde in Luft bei 120° vorsichtig zersetzt. Das dabei erhaltene Ausgangsmaterial (SM) wurde danach in Luft 5 Stunden im Temperaturbereich von 150–1200° thermisch behandelt. Die chemische Analyse von SM ergab, daß als Hauptprodukt der Zersetzung von NH4MnO4, Mn2O3 auftritt neben MnO2, NH4NO3, H2O und O2. Die Bildung von Mn3O4 beginnt bei 900°. Aus Infrarotspektren verschiedener Kalzinierungsprodukte ist ersichtlich, daß in der Gitterstruktur NH 4 + bis 300° zurückgehalten wird und überschüssiger Sauerstoff in Form von koordiniertem O2 vorliegt. Die Ergebnisse der TG-, DTA- und IRA-Untersuchungen von SM bestätigen Daten der chemischen Analyse. Mittels Röntgenanalyse wurden die Phasen identifiziert und der Verlauf der Phasenübergänge und der Bildung einer festen Lösung zwischen MnO2 und Mn2O3 verfolgt.

120°. , , 5 150–1200°. , , , , . 900° Mn3O4. 300° - O 2 . , . , .


Paper presented at the World Conference on Thermal Analysis, Madeira (Portugal), 1986.  相似文献   

18.
The first vertical ionization potentials (I) of phosphorus compounds P(Xi)3, OP(Xi)3, SP(Xi)3, (4-XC6H4)3P, and PCX are related to the inductive, resonance, and polarizability parameters of inorganic, organic, and organometallic substituents X by dependences of the type I = I H + aI + bR + + c, where I H is the I value for X = H. The I values are also affected by hyperconjugation. The ratio of the contributions of the resonance (bR +) and polarizability (c) effects to the I value is determined by the degree of delocalization of the unpaired electron and the positive charge in the radical cations formed upon ionization of neutral molecules. The R + resonance parameters of organosilicon, organogermanium, and organotin substituents bound to the P ·+ radical cation center were calculated for the first time.  相似文献   

19.
Six polyhydroxylated steroids and their derivatives were isolated from the starfish Lysastrosoma anthosticta collected in the Posyet Bay, Sea of Japan. These include a new glycoside of the steroid polyol, lysastroside A (1), which was identified as (25S)-26-O--d-xylopyranosyl-5-cholestane-3,6,8,15,16,26-hexaol, and the previously known pycnopodioside C monoglycoside (2), marthasterone sulfate (3), (25S)-5-cholestane-3,6,8,15,16,26-hexaol (4), (25S)-5-cholestane-3,6,7,8,15,16,26-heptaol (5), and (25S)-5-cholestane-3,6,7,8,15,16,26-heptaol (6). The compounds were tested for the haemolytic activity and the action on the embryogenesis of the sea urchin Strongylocentrotus intermedius.  相似文献   

20.
Conclusions An analysis of the IR spectra of the compounds R3MOCOR, where R and R=CH3, C2H5 or C6H5, testify to a competition between , p-conjugation and d–p-interaction in the M-O bond (for M=Si, Ge), and to the formation of M...O coordination bonds (for M=Sn, Pb).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 164–166, January, 1971.  相似文献   

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