首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The vapour-liquid equilibrium data obtained from isobarict-x-measurements have been used for calculation of the group UNIFAC parameters and excess free enthalpyG E of binary mixturesn-alkanes with isomericn-alkynes. The UNIFAC model gives satisfactory predictions for the systems studied. The temperature dependence ofG E was estimated on the basis of the heats of mixing measured earlier. The influence of the position of triple bond in the molecules ofn-alkynes on the excess thermodynamic functions is considered.
  相似文献   

2.
The reaction of trimethylsilylcarbonamides with halogeno-diorganyl-boranes resp. trihalogenoboranes or organodihalogenoboranes gives monomeric resp. dimeric amidoboranes (borylcarbonamides) and derivatives of 4,8-diaza-1,5-dibora-2,6,9-trioxabicyclo[3.3.1]nonadienes. By reaction of the free acylamides with halogenoboranes in most cases the imide halides could be isolated as the only products. By reaction of the hydrochloride of bis(dimethylamino)-hydroxyborane withn-butyl-lithium followed by addition of the imide halides, the corresponding imidoylamines were formed.1H,11B, and19F-nmr spectra, mass spectra and characteristic ir group frequencies are reported.
15. Mitt.:W. Maringgele undA. Meller, Z. anorg. allg. Chem., im Druck.  相似文献   

3.
The high-resolution207Pb magnetic resonance spectra ofR 4–n PbX n (R=Methyl, Ethyl;X=h1-Cyclopentadienyl, Chloride;n=1, 2) have been studied at 16.72Mc. The207Pb- ·· -1H spin-spin coupling constants for the molecules described have been obtained by analysis of the first order NMR-patterns as AxByM and AxByCzM respectively. The experimental spectra have been verified by a computer simulation. The chemical shifts and coupling constants of the lead organyls investigated show similar dependences on moleculare structure as well as number and species of the substituents like analogous organotin compounds.
  相似文献   

4.
Summary The extraction behaviour of Co and Ni chlorides withAliquat 336-TBP andAliquat 336-TOPO (Aliquat 336: tri-n-octylmethylammonium chloride,TBP: tri-n-butylphosphate,TOPO: tri-n-octylphosphine oxide) was investigated. The synergistic action ofTOPO in the extraction of Co and Ni withAliquat 336 manifested itself in an increase of the distribution ratio of Co with increasing ofTOPO concentration at constantAliquat 336 concentration without deterioration of the separation factor Co/Ni which still was above 200. Mixed complexes of the general formulaMeCl2+mAmBn (Me: Co or Ni,A:Aliquat 336, A:TBP orTOPO) withm ranging from 2 to 5 andn from 1 to 3 were present in the organic phase of both systems. The coexistence of several synergistic Co/Ni species in the equilibrium organic phase is reported for the first time.
Zur Abtrennung von Co und Ni aus chloridhaltigen Medien mitAliquat 336-TBP undAliquat 336-TOPO
Zusammenfassung Das Extraktionsverhalten von Kobalt- und Nickelchloriden mitAliquat 336-TBP undAliquat 336-TOPO (Aliquat 336: Tri-n-octylmethylammoniumchlorid,TBP: Tri-n-butylphosphat,TOPO: Tri-n-octylphosphinoxid) wurde untersucht. Die synergistische Wirkung vonTOPO bei der Extraktion von Co und Ni mitAliquat 336 manifestiert sich in einer Erhöhung des Verteilungsverhältnisses von Co mit steigenderTOPO-Konzentration, ohne daß dadurch der Co/Ni-Trennfaktor verschlechtert wird (> 200). Für beide Systeme konnten in der organischen Phase gemischte Komplexe der allgemeinen FormelMeCl2+m A mBn nachgewiesen werden (Me: Co oder Ni,A:Aliquat 336,B:TBP orderTOPO,m : 2–5,n: 1–3). Zum ersten Mal wird über die Koexistenz verschiedener synergistischer Co/Ni-Spezies in der organischen Phase im Gleichgewicht berichtet.
  相似文献   

5.
Summary The two title compounds12b and13b have been prepared by direct oxidation of the corresponding 10-oxo-19-norcolcalciferol derivatives3c and4c withMCPBA. The generation of12b and13b by treatment of the 7 epoxidized ethylisoxazolin adducts of 5Z- and 5E-cholecalciferol8a,8b and9a,9b with Mo(CO)6 failed, since besides the retroaldol cleavage of the heterocycle a deoxygenation of the oxirane with retention of configuration to the 7 double bond occurs.
  相似文献   

6.
Viscosity measurements were carried out with polyacrylonitrile dissolved in dimethylformamide up to 0.36 g/ml. The temperature range was 20°C to 130°C, the highest shear gradient applied, 5.6·103s–1. The temperature variation of viscosity is reproduced with sufficient accuracy by the equation =k·exp (Q/RT). Bothk andQ increase as concentration increases, and the viscosity increases withc 1.12 toc 6.4 Inverse proportionality appears to exist between concentration and the longest relaxation time.
  相似文献   

7.
Reaction of (RNPF3)2 compounds (R=CH3, C2H5,n-C3H7,n-C4H9,i-C4H9) withN-trimethylsilyl-methylamine leads to nucleophilic substitution of one or two fluorine atoms by the methylamino group, depending on the molar amounts of the reactants. In the case ofR=CH3, two by-products are formed: in the first step a compound with coordination numbers IV, V and VI for the three phosphorus atoms in C5H17F7N5P3 and in the second step a monospiroflourodiaza-5, 5-diphosphetidine.
9. Mitteilung:Utvary, K., Kubjacek, M., Varmuza, K. Z. anorg. allg. Chem.458, 281 (1979).  相似文献   

8.
The interactions of a series of cations with acetamide and its homologs is investigated using1H-n.m.r. spectroscopy. The complexation of a cation by the amide induces changes in the electronic distribution of the ligands which lead to different chemical shifts in the n.m.r. spectra. The results are in agreement withab initio-calculations of the atomic population by the Mulliken Populations Analysis method using a minimal basis set.
  相似文献   

9.
Addition of amines to dibenzylidene sulfamide1 a yields the correspondingSchiff bases3 a, b and monobenzylidene sulfamide2. Reaction of several dibenzylidene sulfamides1 with various lithium-amides gives N1-substituted N2-benzylsulfamoyl-benzamidines7 a-k via an intramolecular hydride transfer reaction, whereas by treatment of1 a with sodium amide 2-benzyl-3,5-diphenyl-3,4-dihydro-2H-1,2,4,6-thiatriazine-1,1-dioxide8 is obtained, which on hydrolysis yields9 and11. Alkylation products are described, the isomeric products12a/13a and12b/13b are isolated, their structures are confirmed by synthesis, IR and NMR-spectra.
  相似文献   

10.
Excess enthalpies, and heat capacities derived therefrom, have been obtained between 25 and 65 or 75°C at a constant concentration for cyclohexane and octamethylcyclotetrasiloxane mixed with normal hexadecane and with a highly branched C16 isomer, 2,2,4,4,6,8,8-heptamethylnonane, and also forcis-andtrans-decalin mixed withn-C16. Theh E values withn-C16 are positive and much larger than with the branched-C16. They decrease rapidly withT so thatc p E is large and negative. These results imply the presence of orientational order in then-C16, which is destroyed on mixing with the other component and which decreases withT. Theh E fortrans-decalin+n-C16 is much smaller than forcis-decalin+n-C16, and becomes negative with increase ofT. This change of sign, which is unexplained by current theory, is interpreted as due to an interference of the flat, plateliketrans-decalin molecule with the molecular motion of then-C16 chain.  相似文献   

11.
Substituted azafulvenes were generated by dehydrogenation of 5-methyl-substituted pyrromethenones withDDQ and characterized by UV- and1H-NMR-spectroscopy. Their electrophilic properties were demonstrated using several quenchers and furthermore they were used for a synthesis of verdinoid bile pigments (which easily can be converted to rubinoid systems by the action of NaBH4) with nearly any desired unsymmetrical alkyl substitution patter: The azafulvene spezies was generated by the action ofDDQ on a 5-methylpyrromethenone and was quenched by an 5-unsubstituted pyrromethenone. The resulting rubinoid adduct was dehydrogenated immediatly byDDQ — yields were good to high.
39. Mitt.:Falk, H., Höllbacher, G., Hofer, O., Müller, N., Mh. Chem.112, 391 (1981).  相似文献   

12.
The statistical thermodynamics of adsorption from multicomponent liquid mixtures on heterogeneous solid surfaces is discussed by assuming the cell adsorption model and ideal adsorbed phase.Two integral representations for the adsorption isotherm are proposed: one based onn-dimensional energy distribution function (i.e., each adsorption site is characterized by adsorption energies of all components), and the other based on distribution of differences of adsorption energies ofn-1 components in relation to adsorption energy of the chosen component (i.e., each adsorption site is characterized byn-1 differences of adsorption energies of the components in relation to adsorption energy of the chosen component).The expressions for differential adsorption heat for adsorption from binary liquid mixtures have been derived from both integral equations.
Statistische Thermodynamik der Adsorption aus flüssigen Mehrkomponentenmischungen auf heterogenen festen Oberflächen
Zusammenfassung Die statistische Thermodynamik der Adsorption von aus mehreren Komponenten bestehenden flüssigen Mischungen auf heterogenen festen Oberflächen wird für das Modell der Zellenadsorption bei ideal adsorbierter Phase diskutiert.Zwei Integraldarstellungen der Adsorptionsisotherme werden vorgeschlagen: eine auf einen-dimensionale Verteilungsfunktion der Energie gestützte (das heißt, jede Adsorptionsstelle wird durch Adsorptionsenergien von allen Komponenten charakterisiert); die andere basiert auf der Verteilung der Unterschiede von Adsorptionsenergien dern-1-Komponenten in bezug auf die Adsorptionsenergie der ausgewählten Komponente (das heißt, jede Adsorptionsstelle wird durchn-1-Unterschiede charakterisiert. Formeln für differentiale Adsorptionswärmen für die Adsorption aus binären flüssigen Mischungen sind von beiden Integral-Gleichungen abgeleitet worden.
  相似文献   

13.
The 2-cyclohexenones1 a andd resp. react with urea in HCl/EtOH to give 1-hydroxy-4-methyl-7-phenyl- and 1-hydroxy-2,4-diazabicyclo[3.3.1]nonane-3-ones3a and3d resp., whereas the 2-cyclohexenones1b andc resp. transformed by urea to 1,7-dimethyl- and 1-methyl-4-ureido-2,4-diazabicyclo[3.3.1]nonan-3-ones9b andc resp. In the condensation of isophorone1e with urea a product C13H28N8O4 of indisdinct structure was formed, whereas the bicyclus3e could not be isolated.Reaction ofAcOAc with3a yielded the 5-methyl-3-oxo-7-phenyl-2,4-diazabicyclo[3.3.1]non-1-ylacetate (15); on heating of3a with acids decomposition to1a and urea took place. NoWagner-Meerwein-rearrangement was observed. The MS-spectra of3a andd are discussed; NMR- and IR-data are reported.No significant herbicidal, fungicidal or insecticidal activity was found in screening-tests on3a.
  相似文献   

14.
Silyl-substitutedo-carboranes 1-R-2-Me3Si(CH2) n -1,2-C2B10H10 (R=Me, Ph;n=0, 1) undergo transmetallation on treatment with BunLi to form lithium derivatives ofo-carboranes, 1-R-2-Li(CH2) n -1,2-C2B10H10, wheren=0, 1. A silicon derivative ofo-carborane, 1-Ph-2-(Me3SiCHPh)-1,2-C2B10H10, undergoes neither transmetallation nor metallation at the benzyl CH-group on treatment with BunLi due to significant steric hindrance. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 492–494, March, 1998.  相似文献   

15.
Deprotonation of 3,4-dimethyl-3-pyrrolin-2-on (1) int-butyl alcohol/potassiumt-butoxide solutions takes place on the N atom, as shown by1H/2H exchange andpK a determinations of1 (pK=17.1), 1,3,4-trimethyl-3-pyrrolin-2-one (pK a =17.6), and 3,4-dimethyl-5-methoxy-2H-pyrrole (pK a =16.7). The SCF-MO approximation MINDO/3 indicates, however, that in the gas phase deprotonation of1 should occur at the C atom.
1.Mitt.:Ribó, J. M., Trull, F., Mh. Chem.110, 201 (1979).  相似文献   

16.
Nickel(0)-olefine π-complexes such as Ni(C2H4)3 and Ni(C2H4)(PR3)2 [6] prepared by conventional ligand replacement reaction are diamagnetic and stable up to room temperature. Similar π-complexes e.g. Ni(C2H4) n (withn = 1, 2 or 3) generated by cryo-condensation technique [3] may exist in a paramagnetic state which derives from the triplet ground state of the atomic nickel. The stability of (η2-ethylene) nickel has been explained byab initio-MO calculations relating the energies of the complexes to different terms (1 S and3 F) of the nickel atom.
  相似文献   

17.
Summary NMR-spectroscopic investigations of substituted dithiocarbacinic acid derivatives show the existence of configurational isomers relative to the C=N double bond, but no tautomerism. We applied chemical shift differences in the1H-,13C- and15N-NMR-spectra, N - H and C - H coupling constants and NOE difference measurements in the solvents CDCl3,DMSO-d 6 and partly CD3OD in order to discriminate between the isomers and to determine the configurational composition. Compounds4 and5 exist asE-isomers in all solvents, compounds1, 2 and3 as a mixture ofE/Z-isomers. InDMSO-d 6 theE-form is the preferred isomer.
  相似文献   

18.
Summary The aggregation equilibria ofdi(2,4,4-trimethylpentyl)phosphinic acid (HDTMPP) anddi(n-octyl)phosphinic acid (HDOP) dissolved in toluene have been investigated by vapour-pressure osmometry (VPO) at different temperatures. The experimental data have been treated both graphically and numerically, and the average aggregation numberñ as well as the aggregation constant have been determined. The results suggest that dimers are formed and that the dimerization constant decreases with temperature. Finally, the enthalpies for the aggregation ofdi(2,4,4-trimethylpentyl)phosphinic acid anddi(n-octyl)phosphinic acid in toluene have been estimated using thevan't Hoff equation.
Über die Wechselwirkung metallextrahierender Reagentien. Untersuchung der Aggregation vondi-(2,2,4-Trimethylpentyl)-phosphinsäure unddi-(n-Octyl)-phosphinsäure in Toluol mittels Dampfdruckosmometrie
Zusammenfassung Die Aggregationsgleichgewichte von in Toluol gelösterdi-(2,4,4-Trimethylphentyl)-phosphinsäure (HDTMPP) unddi-(n-Octyl)-phosphinsäure (HDOP) wurden mittels Dampfdruckosmometrie (VPO) bei verschiedenen Temperaturen untersucht. Die experimentellen Daten wurden sowohl graphisch als auch numerisch ausgewertet; es wurden sowohl die mittlere Aggregationszahlñ als auch die Aggregationskonstante bestimmt. Die Resultate lassen vermuten, daß Dimere gebildet werden und die Dimerisationskonstante mit der Temperatur abnimmt. Mit Hilfe dervan't Hoffschen Gleichung wurden die Enthalpien der Aggregation vondi-(2,4,4-Trimethylpentyl)-phosphinsäure unddi-(n-Octyl)-phosphinsäure in Toluol abgeschätzt.
  相似文献   

19.
In acetic (aqueous or chloroform) solutionp-benzoquinones yield with primary aliphatic amines mainly 2-(N-alkyl-p-hydroxy-anilino)-1,4-benzoquinones besides the 2-alkylamino- and 2,5-bis(alkylamino)-quinones. The methyl-, ethyl-,n-propyl-,n-butylhomologues ofp-benzoquinone and the isomer methylderivatives of toluquinone are described. Their structure were established by spectroscopic (UV/VIS, IR, NMR) methods and by synthesis of the methylderivative3 a fromp-benzoquinone andp-hydroxy-N-methylaniline. The influence of other acids on the reaction was studied.
Herrn Prof. Dr.G. Zigeuner, Universität Graz, mit den besten Wünschen zum 60. Geburtstag gewidmet.  相似文献   

20.
Neighbouring effects during mercuryEDTA dehydrogenation yield with1 the vinylogous acylamidinium compound11 and with2, 3 and6 the vinylogous amidinium derivatives8–10.
Herrn Professor Dr.H. Bretschneider zur Vollendung des 75. Lebensjahres gewidmet  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号