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1.
Zusammenfassung Die magnetische Nichtäquivalenz der Methylenprotonen in 2-R-Benzo-1,3-dioxanen, mit R=C6H5,o-ClC6H4,m-ClC6H4,p-ClC6H4,o-BrC6H4,m-BrC6H4,p-BrC6H4,o-NO2C6H4,m-NO2C6H4,p-NO2C6H4,o-CH3OC6H4,m-CH3OC6H4,p-CH3OC6H4, -Naphthyl, -Naphthyl, -Thienyl und -Thienyl, wurde in (CD3)2CO, CDCl3, CCl4, CS2 und C6D6 untersucht.
Magnetic non equivalent methylenic protons of some 2-substituted 1.3-benzodioxanes
The magnetic non equivalence of the methylenic protons in 2-R-1.3-benzodioxanes, with R=C6H5,o-ClC6H4,m-ClC6H4,p-ClC6H4,o-BrC6H4,m-BrC6H4,p-BrC6H4,o-NO2C6H4,m-NO2C6H4,p-NO2C6H4,o-CH3OC6H4,m-CH3OC6H4,p-CH3OC6H4, -naphthyl, -naphthyl, -thienyl and -thienyl were studied in (CD3)2CO, CDCl3, CCl4, CS2 and C6D6.
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2.
The kinetics of the photolytic CO-substitution of CpFe(CO)2SCOR [Cp = C5H5, Bu t C5H4, 1,3-Bu2 t C5H3; R = Me, Bu t , Ph, 2-(O2N)C6H4, 3-(O2N)C6H4, 4-(O2N)C6H4, 3,5-(O2N)2C6H3] with PPh3 were studied in CH2Cl2 at 0 °C by i.r. spectroscopy. The reactions yielded exclusively the mono-CO-substituted derivatives, CpFe-(CO)(PPh3) SCOR, and were found to follow second order kinetics with first order dependence on the concentration of each reactant. The differences in rates are discussed in terms of current knowledge pertaining to such reactions. An associative mechanism is proposed to account for the kinetic data of the reactions described.  相似文献   

3.
Zusammenfassung Die Floating-Gaussian-Orbital (FGO)-Methode von Frost [5] macht einfache ab-initio-SCF-Rechnungen für mittelgroße Moleküle möglich. Wir vergleichen gemäß Koopmans Theorem die Orbitalenergien von (z.T. modifizierten) FGO-Rechnungen für CH4, C2H2, C2H4, C2H6, C3H6, C4H8 mit den entsprechenden Photoelektron-Spektren.
The interpretation of photoelectron spectra by the Floating Gaussian Orbital-model
With Frost's Floating Gaussian Orbital (FGO)-method [5] simple ab-initio-SCF-calculations for medium-size molecules are possible. Based on Koopmans theorem we compare the orbital energies of (partially modified) FGO-calculations for CH4, C2H2, C2H4, C2H6, C3H6, C4H8 with the corresponding photoelectron spectra.

Résumé Avec la méthode des Floating Gaussian Orbitals (FGO) de Frost [5] il est possible d'effectuer des calculs simples SCF-ab-initio pour des molécules de largeur moyenne. Nous comparons suivant le théorème de Koopmans les énergies orbitales des calculs FGO (partiellement modifiés) pour CH4, C2H2, C2H4, C2H6, C3H6, C4H8 avec les spectres de photoionisation correspondants.


Diese Arbeit ist Teil des Projekts Nr. SR 2.120.69 des Schweizerischen Nationalfonds. Die Rechnungen wurden auf der Univac 1108 der Firma Sandoz AG, Basel durchgeführt. Wir danken der Leitung und dem Personal des Rechenzentrums für Rechenzeit und für sorgfältige Arbeiten.  相似文献   

4.
A new, efficient and easy route for the preparation of a series of 2‐alkyl(aryl) substituted 4‐oxo‐4H‐pyrido‐[1,2‐a]pyrimidines, where alkyl = CH3; aryl = C6H5, 4‐FC6H4, 4‐ClC6H4, 4‐BrC6H4, 4‐CH3C6H4, 4‐OCH3C6H4, 4‐NO2C6H4 in 45–80 % yield from the reaction of β‐alkoxyvinyl trichloromethyl ketones with 2‐aminopyridine under mild conditions, is then reported.  相似文献   

5.
Conventional transition-state theory is used for extrapolating rate coefficients for reactions of O atoms with alkanes to temperatures above the range of experimental data. Expressions are developed for estimating structural properties of the activated complex necessary for calculating enthalpies and entropies of activation. Particular attention is given to the problem of the effect of the O atom adduct on the internal rotations in the activated complex. Differences between primary, secondary, and tertiary attack are discussed, and the validity of representing the activated complexes of all O + alkane reactions by a fixed set of vibrational frequencies and other internal modes is evaluated. Experimental data for reactions of O atoms with 15 different alkanes (CH4, C2H6, C3H8, C4H10, C5H12, C6H14, C7H16, C8H18, i–C4H10, (CH3)4C, (CH3)2CHCH(CH3)2, (CH3)3CC(CH3)3, c–C5H10, c–C6H12, c–C7H14) are reviewed. The following approximate expressions for ΔS?(298) and E(298), the entropy and energy of activation, respectively, are consistent with the experimental data and with the calculations: where nC = number of carbon atoms in the alkane and nH = the number of “equivalent” H atoms. Using the conventional transition state theory expression, k(298) = 1015.06 exp(ΔS?/R) exp(–E(298)/298R) L mol?1s?1, one then obtains: These expressions agree with experimental values within a factor approximately 2 for alkanes larger than C3H8.  相似文献   

6.
Summary. Group 2B transition metal complexes of bis[N-(2,6-diisopropylphenyl)imino]acenaphthene (o,o-iPr2C6H3-BIAN), namely, [Hg(o,o-iPr2C6H3-BIAN)Cl2] (1), [Zn(o,o-iPr2C6H3-BIAN)2](ClO4)2 (2), and [Cd(o,o-iPr2C6H3-BIAN)2](ClO4)2 (3) have been synthesized and characterized. In complexes 2 and 3, IR, NMR, and conductivity measurements confirm the coordination of two (o,o-iPr2C6H3-BIAN) ligands to the metal center with two discrete perchlorate anions. X-Ray crystal structure of 1 indicates a distorted tetrahedral geometry with two nitrogen atoms from (o,o-iPr2C6H3-BIAN) ligand and two chloride atoms coordinating to the Hg(II) center.  相似文献   

7.
Group 2B transition metal complexes of bis[N-(2,6-diisopropylphenyl)imino]acenaphthene (o,o-iPr2C6H3-BIAN), namely, [Hg(o,o-iPr2C6H3-BIAN)Cl2] (1), [Zn(o,o-iPr2C6H3-BIAN)2](ClO4)2 (2), and [Cd(o,o-iPr2C6H3-BIAN)2](ClO4)2 (3) have been synthesized and characterized. In complexes 2 and 3, IR, NMR, and conductivity measurements confirm the coordination of two (o,o-iPr2C6H3-BIAN) ligands to the metal center with two discrete perchlorate anions. X-Ray crystal structure of 1 indicates a distorted tetrahedral geometry with two nitrogen atoms from (o,o-iPr2C6H3-BIAN) ligand and two chloride atoms coordinating to the Hg(II) center.  相似文献   

8.
The regiospecific synthesis of a new series of eight 3‐alkyl(aryl)‐5‐hydroxy‐5‐trichloromethyl‐4,5‐dihydro‐1H‐1‐tosylpyrazoles is reported. The 1‐p‐tosyl‐2‐pyrazolines were obtained from the cyclocondensation reaction of 4‐alkyl(aryl)‐4‐alkoxy‐1,1,1‐trichloroalk‐3‐en‐2‐ones, [where alkyl = H, Me and aryl = ‐C6H5, 4‐CH3C6H4, 4‐OCH3C6H4, 4‐FC6H4, 4‐ClC6H4, 4‐BrC6H4,] with p‐tosylhydrazine in 64 to 92 % yields, employing anhydrous toluene at reflux or diethyl ether at room temperature as the reaction condition.  相似文献   

9.
At DFT/B3LYP/6‐31G** theoretical level, C6H and C (n = 0, ?2, and +2), C6H and C (n = 0, ±2, ±4, and ±6), C6H (n = 0–6), as well as C6H6‐A and C6‐A (A = Be, B, N, O, Mg, Al, Si, S, and Fe) structures were investigated. Comparing NICS values of C6H and C (n = 0, ?2, and +2), we discovered that C6H, C6H were antiaromatic, and C6H6, C6, C, C had aromaticity with negative NICS values. According to research of C6H and C (n = 0, ±2, ±4, ±6), C6H (n = 0–6), we sustained that their σ and π orbit were different and the locations of electrons were difficult to confirm in ionic structures. Thus, neither 4n + 2 rule nor NICS values can precisely estimate the aromaticity of ionic structures. Besides, through WBI (NBO) research of C6H6‐A and C6‐A (A = Be, B, N, O, Mg, Al, Si, S, and Fe) structures, we found that C6H6 was easy to accept electrons, contrarily, C6 was prone to bestowing electrons. Moreover, C6H6 took the symmetrical carbon atoms form feeble interaction or bond, and C6 used all carbon atoms to impact with other atom. C6H6 generated two contrapuntal single bonds with oxygen, sulfur, and nitrogen atoms, whereas C6 molecule formed double bond with oxygen and nitrogen atoms, two conjoint single bonds with sulfur atom. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010  相似文献   

10.
The aromaticity, anti-aromaticity, and two new types of behaviour of pi-hydrocarbons with one or more C m H m rings attached by polyene bridges and with or without several polyene side chains are readily obtainable on the blackboard directly from the structural formulae using the general pictorial method recently presented. The HOMO-LUMO types, number of non-bonding MOs, and qualitative stability are also deduced. The single pi-rings fall into four homolog classes characterized by their first members C3H3, C4H4, C5H5, and C6H6 rather than the two previous Hückel 4n, 4n + 2 types. A general rule for finding the number of NBMOs for bridged combinations of such ring types is given.  相似文献   

11.
The preparation of ylides of the general structure is described. Thermolysis of 14a (R = CH3, R' = H, Ar = C6H5) gave dimethylamine and 2,4-dimethyl-6-phenyl-s-triazine. Thermolysis of ylides 14b (R = C6H5; R' = CH3, Ar = C6H5) and 14c (R = C6H5, R' = CH3, Ar = p-tolyl) gave dimethylamine, ArCH = NCH3 and 1-methyl-2-Ar-4,6-diphenyl-1,2-dihydro-s-triazines ( 19a,b ). Triazines 19a and 19b were also prepared by condensation of N-methylbenzamidine with benzaldehyde and p-tolualdehyde, respectively. Thermolysis of 14d (R = C6H5, R1 = CH2C6H5,Ar = C6H5) gave 1-benzyl-2,4,6-triphenyl-1,2-dihydro-s-triazine ( 19c ) and N-benzylidenebenzylamine. Mechanistic aspects of these reactions are discussed.  相似文献   

12.
Two coordination polymers {[Cd(phen)](C6H8O4)3/3} ( 1 ) and {[Cd(phen)](C7H10O4)3/3} · 2H2O ( 2 ) were structurally characterized by single crystal X‐ray diffraction methods. In 1 (C2/c (no. 15), a = 16.169(2)Å, b = 15.485(2)Å, c = 14.044(2)Å, β = 112.701(8)°, U = 3243.9(7)Å3, Z = 8), the Cd atoms are coordinated by two N atoms of one phen ligand and five O atoms of three adipato ligands to form mono‐capped trigonal prisms with d(Cd‐O) = 2.271‐2.583Å and d(Cd‐N) = 2.309, 2.390Å. The [Cd(phen)] moieties are bridged by adipato ligands to generate {[Cd(phen)](C6H8O4)3/3} chains, which, via interchain π—π stacking interactions, are assembled into layers. Complex 2 (P1¯(no. 2), a = 9.986(1)Å, b = 10.230(3)Å, c = 11.243(1)Å, α = 66.06(1)°, β = 87.20(1)°, γ = 66.71(1)°, U = 955.7(2)Å3, Z = 2) consists of {[Cd(phen)](C7H10O4)3/3} chains and hydrogen bonded H2O molecules. The Cd atoms are pentagonal bipyramidally coordinated by two N atoms of one phen ligand and five O atoms of three pimelato ligands with d(Cd‐O) = 2.213—2.721Å and d(Cd‐N) = 2.329, 2.372Å. Through interchain π—π stacking interactions, the {[Cd(phen)](C7H10O4)3/3} chains resulting from [Cd(phen)] moieties bridged by pimelato ligands are assembled in to layers, between which the hydrogen bonded H2O molecules are sandwiched.  相似文献   

13.
The synthesis of a novel series of the intermediates N2(N3)‐[1‐alkyl(aryl/heteroaryl)‐3‐oxo‐4,4,4‐trifluoroalk‐1‐en‐1‐yl]‐2‐aminopyridines [F3CC(O)CH?CR1(2? NH?C5H3N)] and 2,3‐diaminopyridines [F3CC(O)CH?CR1(2‐NH2‐3‐NH? C5H3N)], where R1 = H, Me, C6H5, 4‐FC6H4, 4‐CIC6H4, 4‐BrC6H4, 4‐CH3C6H4, 4‐OCH3C6H4, 4,4′‐biphenyl, 1‐naphthyl, 2‐thienyl, 2‐furyl, is reported. The corresponding series of 2‐aryl(heteroaryl)‐4‐trifluoromethyl‐3H‐pyrido[2,3‐b][1,4]diazepin‐4‐ols obtained from intramolecular cyclization reaction of the respective trifluoroacetyl enamines or from the direct cyclocondensation reaction of 4‐methoxy‐1,1,1‐trifluoroalk‐3‐en‐2‐ones with 2,3‐diaminopyridine, under mild conditions, is also reported.  相似文献   

14.
Relative rate constants for the removal of vibrationally excited OH in the ninth vibrational level of its ground electronic state [designated hereafter by OH? (9)] by interaction with a series of simple hydrocarbons at room temperature are reported. The reaction of hydrogen atoms with ozone was used to generate OH?(9) in a fast flow discharge system at 1.1 ± 0.1 torr total pressure. The decrease in the (9 → 3 band) Meinel band chemiluminescent emission intensity at 626 nm was followed as a function of the concentration of added organic or of a reference deactivator (O2), respectively, at a fixed reaction time; these data gave relative rate constants, k/k, for the removal of OH?(9) by the organic. The relative rate constants determined in this study are as follows: C2H6, 2.7 ± 0.2; C3H8, 4.4 ± 0.4; n–C4H10, 7.5 ± 0.6; iso–C4H10, 7.3 ± 0.8; n–C5H12, 10.4 ± 0.7; C2H4, 22.9 ± 1.8; C3H6, 43.4 ± 1.4; cis–2–C4H8, 47.7 ± 3.1; C6H6, 29 ± 7. (Errors are two standard deviations of the weighted mean of experiments in two flow tubes with different wall coatings and carrier gases.) The implications of the trends in these rate constants for the relative contributions of energy transfer and reaction to the net removal of OH? (9) are discussed.  相似文献   

15.
We have calculated certain dynamic polarizabilities (for both real and imaginary frequencies) for H, He, and H2 and the dispersion-energy coefficients for long-range interactions between them. We have done so in a sum-over-states formalism with explicitly electron-correlated wave functions to describe the states. To be precise, we have determined the dipole (α1), quadrupole (α2), and octupole (α3) polarizabilities of H and He for real frequencies (ω) in a range between zero and the first electronic-transition frequency and for imaginary frequencies (iω) on a 32-point Gauss-Legendre grid running from zero to ?ω = 20 Eh, and for H2, we have found the dipole (α), quadrupole (C), and dipole–octupole (E) polarizability tensors for the same real and imaginary frequencies. The dispersion-energy coefficients, obtained by combining the sum-over-states for-malism for the polarizabilities with analytic integration over ω, gave values of C6, C8, and C10 for the atom–atom systems; C, C, C, C, and C for the atom–diatom systems; and C6, C and C for the H2? H2 system. Nearly all the results are considered to be more reliable than those hitherto published and some have been obtained for the first time, e.g., C(iω), E(ω), and E(iω) for H2 and C, C, and C for the H? H2 system. © 1993 John Wiley & Sons, Inc.  相似文献   

16.
Loss of CH, CH4, C2H4, C3H, C3H6 and C3H7 from the molecular ions of a number of 13C-labeled analogs of 4,4-dimethyl-1-pentene was studied both in normal (source) 70-eV electron impact (EI) spectra dn in metastable spectra. For loss of CH in the source, 96% of the methyl comes frm positions of 5, 5′ and 5″, while the remainder comes from position 1. In the metastable spectra, loss of C-1 (16%) and C-3 (9%) is increasing in importance. The loss of ethylene is a particular case: either C-1 or C-3 are lost with any other C-atom from positions 2,5,5′, and 5″ (8 × 10%) in the metastable spectra, the probability for simultaneous loss of C-1 and C-3 being 6%. If C-1 seems to these two positions become completely equivalent in the metastable time range. The T-values (kinetic energy release) for the different positions show small, but statisticaly different values and a small isotope effect. Loss of C3H5 (allylic cleavage) is 100% C-1, C-2 and C-3, i.e., no evidence for skeletal rearrangement is seen. This is also true for loss of C3C6 (McLafferty rearrangement) within the source, but in metastable decay the other positions gain in importance. The neutral fragment C3H appears to be the the result of consecutive loss of CH and C3H4, rather than a one-step loss of propyl radical or the inverse reactions sequence. No metastable reaction can be seen for this reaction. Decomposition of labeled C6H and C5H secondary ions occurs in an essentially random fashion.  相似文献   

17.
Five-membered cyclic esters of phosphoric acid of the general formula: ? CH2CH(R)OP(O)-(OR′)O? polymerize readily to solid, soluble polymers of high molecular weight without any rearrangement known for various tri- and pentavalent organophosphorus monomers. 1H-, 13C-, and 31P-NMR spectra of polymers confirmed their linear structure: where R is H, with R′ = CH3, C2H5, n-C3H7, i-C3H7; n-C4H9, CCl3CH2, or C6H5, or R is CH2Cl and R′ is C2H5. The use of n-C4H9Li, (C5H5)2Mg, or (i-C4H9)3Al as initiators leads to polymers with M n = 104–105.  相似文献   

18.
Using the results of ab initio calculations, by comparison of the “1s orbital energies” of the C atom in the compounds C6H6, C5H, C3H6 (cyclopropane), C2H4 as well as at the C atom itself the bond electrons were found to have a significant influence on the inner electrons. The reason for this is pointed out and an explanation is given. The connection between the bonding and this “1s orbital energy” change as well as the importance of this result for quantum-chemical “models” is discussed.  相似文献   

19.
Two solvates of fluorinated derivatives of C60 fullerene were studied by single-crystal X-ray diffraction analysis. The crystals of fluorinated fullerene solvate C60F18·C6H5Me belong to the monoclinic system with the unit cell parameters a = 11.532(2) , b = 21.501(3) , c = 16.261(2) , = 101.798(5)°. The fluorinated fullerene molecule with the approximate symmetry C 3v occupies a general position. The crystals of fluorinated fullerene solvate C60F48·2C6H3Me3 belong to the cubic system (a = 23.138(2) ). The C60F48 molecule occupies the special position with the S 6 symmetry. The experimental molecular geometry agrees with the results of quantum-chemical calculations.  相似文献   

20.
Reaction of the Schiff base ligand derived from 4-pyridinecarboxaldehyde NC5H4C(H)N[2′,4′,6′-(CH3)C6H2], (1), with palladium(II) acetate in toluene at 60 °C for 24 h gave [Pd{NC5H4C(H)N[2′,4′,6′-(CH3)C6H2]}2(OCOCH3)2], (2), with two ligands coordinated through the pyridine nitrogen. Treatment of the Schiff base ligand derived from 4-pyridinecarboxaldehyde N-oxide, 4-(O)NC5H4C(H)N[2′,4′,6′-(CH3)C6H2], (4), with palladium(II) acetate in toluene at 75 °C gave the dinuclear acetato-bridged complex [Pd{4-(O)NC5H3C(H)N[2′,4′,6′-(CH3)C6H2]}(OCOCH3)]2, (5) with metallation of an aromatic phenyl carbon. Reaction of complex 5 with sodium chloride or lithium bromide gave the dinuclear halogen-bridged complexes [Pd{4-(O)NC5H3C(H)N[2′,4′,6′-(CH3)C6H2]}(Cl)]2, (6) and [Pd{4-(O)NC5H3C(H)N[2′,4′,6′-(CH3)C6H2]}(Br)]2, (7), after the metathesis reaction. Reaction of 6 and 7 with triphenylphosphine gave the mononuclear species [Pd{4-(O)NC5H3C(H)N[2′,4′,6′-(CH3)C6H2]}(Cl)(PPh3)], (8) and [Pd{4-(O)NC5H3C(H)N[2′,4′,6′-(CH3)C6H2]}-(Br)(PPh3)], (9), as air stable solids. Treatment of 6 and 7 with Ph2P(CH2)2PPh2 (dppe) in a complex/diphosphine 1:2 molar ratio gave the mononuclear complexes [Pd{4-(O)NC5H3C(H)N[2′,4′,6′-(CH3)C6H2]}(PPh2(CH2)2PPh2)][Cl], (10), and [Pd{4-(O)NC5H3C(H)N[2′,4′,6′-(CH3)C6H2]}(PPh2(CH2)2PPh2)][PF6], (11), with a chelating diphosphine. The molecular structure of complex 9 was determined by X-ray single crystal diffraction analysis.  相似文献   

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