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T.E. Vittal Prasad N. Malleswara Reddy 《The Journal of chemical thermodynamics》2006,38(12):1696-1700
Bubble point temperatures at 95.5 kPa, over the entire composition range, are measured for the binary mixtures formed by m-cresol with: methanol, ethanol, 1-propanol, 2-propanol, and n-, iso-, sec-, and tert-butanols - using a Swietoslawski-type ebulliometer. The liquid phase composition - bubble point temperature measurements are well represented by the Wilson model. (Vapor + liquid) equilibria predicted from the model are presented. 相似文献
5.
Yano J Sauer K Girerd JJ Yachandra VK 《Journal of the American Chemical Society》2004,126(24):7486-7495
The anisotropic g and hyperfine tensors of the Mn di-micro-oxo complex, [Mn(2)(III,IV)O(2)(phen)(4)](PF(6))(3).CH(3)CN, were derived by single-crystal EPR measurements at X- and Q-band frequencies. This is the first simulation of EPR parameters from single-crystal EPR spectra for multinuclear Mn complexes, which are of importance in several metalloenzymes; one of them is the oxygen-evolving complex in photosystem II (PS II). Single-crystal [Mn(2)(III,IV)O(2)(phen)(4)](PF(6))(3).CH(3)CN EPR spectra showed distinct resolved (55)Mn hyperfine lines in all crystal orientations, unlike single-crystal EPR spectra of other Mn(2)(III,IV) di-micro-oxo bridged complexes. We measured the EPR spectra in the crystal ab- and bc-planes, and from these spectra we obtained the EPR spectra of the complex along the unique a-, b-, and c-axes of the crystal. The crystal orientation was determined by X-ray diffraction and single-crystal EXAFS (Extended X-ray Absorption Fine Structure) measurements. In this complex, the three crystallographic axes, a, b, and c, are parallel or nearly parallel to the principal molecular axes of Mn(2)(III,IV)O(2)(phen)(4) as shown in the crystallographic data by Stebler et al. (Inorg. Chem. 1986, 25, 4743). This direct relation together with the resolved hyperfine lines significantly simplified the simulation of single-crystal spectra in the three principal directions due to the reduction of free parameters and, thus, allowed us to define the magnetic g and A tensors of the molecule with a high degree of reliability. These parameters were subsequently used to generate the solution EPR spectra at both X- and Q-bands with excellent agreement. The anisotropic g and hyperfine tensors determined by the simulation of the X- and Q-band single-crystal and solution EPR spectra are as follows: g(x) = 1.9887, g(y) = 1.9957, g(z) = 1.9775, and hyperfine coupling constants are A(III)(x) = |171| G, A(III)(y) = |176| G, A(III)(z) = |129| G, A(IV)(x) = |77| G, A(IV)(y) = |74| G, A(IV)(z) = |80| G. 相似文献
6.
Schumm BA Koetke DS Adolphsen CE Alexander JP Averill D Barish BC Barklow T Barnett BA Blockus D Boyarski A Brabson B Breakstone A Bulos F Burchat PR Burke DL Cence RJ Chapman J Chmeissani M Cords D Coupal DP Dauncey P DeStaebler HC Dorfan JM Drell PS Drewer DC Durrett D Elia R Feldman GJ Field RC Ford WT Fordham C Frey R Fujino D Gan KK Gero E Gidal G Glanzman T Goldhaber G Gomez Cadenas JJ Gratta G Hanson G Harr R Harral B Harris FA Hayes K Hearty C Heusch CA Hildreth MD Himel T Hinshaw DA 《Physical review D: Particles and fields》1992,46(1):453-456
7.
Exploiting the ability of the [M(SC[O]Ph)(4)](-) anion to behave like an anionic metalloligand, we have synthesized [Li[Ga(SC[O]Ph)(4)]] (1), [Li[In(SC[O]Ph)(4)]] (2), [Na[Ga(SC[O]Ph)(4)]] (3), [Na(MeCN)[In(SC[O]Ph)(4)]] (4), [K[Ga(SC[O]Ph)(4)]] (5), and [K(MeCN)(2)[In(SC[O]Ph)(4)]] (6) by reacting MX(3) and PhC[O]S(-)A(+) (M = Ga(III) and In(III); X = Cl(-) and NO(3)(-); and A = Li(I), Na(I), and K(I)) in the molar ratio 1:4. The structures of 2, 4, and 6 determined by X-ray crystallography indicate that they have a one-dimensional coordination polymeric structure, and structural variations may be attributed to the change in the alkali metal ion from Li(I) to Na(I) to K(I). Crystal data for 2 x 0.5MeCN x 0.25H(2)O: monoclinic space group C2/c, a = 24.5766(8) A, b = 13.2758(5) A, c = 19.9983(8) A, beta = 108.426(1) degrees, Z = 8, and V = 6190.4(4) A(3). Crystal data for 4: monoclinic space group P2(1)/c, a = 10.5774(7) A, b = 21.9723(15) A, c = 14.4196(10) A, beta = 110.121(1) degrees, Z = 4, and V = 3146.7(4) A(3). Crystal data for 6: monoclinic space group P2(1)/c, a = 12.307(3) A, b = 13.672(3) A, c = 20.575(4) A, beta = 92.356(4) degrees, Z = 4, and V = 3458.8(12) A(3). The thermal decomposition of these compounds indicated the formation of the corresponding AMS(2) materials. 相似文献
8.
The phosphapalladacycle derived from 1-(2',5'-dimethylphenyl)ethyldiphenylphosphine has been prepared in the optically active and racemic forms. The phosphine was synthesized as a racemate by the treatment of 1-chloro-1-(2',5'-dimethylphenyl)ethane with sodium diphenylphosphide in THF. The racemic phosphapalladacycle was subsequently obtained as the chloro-bridged dimer by the treatment of the phosphine with palladium(II) acetate followed by anion metathesis with lithium chloride. Alternatively, the phosphine could be optically resolved via metal complexation using (R,R)-bis(mu-chloro)bis{1-[1-(N,N-dimethylamino)ethyl]naphthyl-C(2),N}dipalladium(II) as the resolving agent. An efficient separation of the resulting diastereomeric complexes was achieved by silica gel chromatography. The obtained optically resolved diastereomers were next subject to chemoselective removal of the (R)-N,N-(dimethylamino)-1-(1-naphthyl)ethylaminate auxiliary by treatment with concentrated hydrochloric acid. This process yielded the binuclear dimer complexes containing the resolved eta(1)-P ligand. Cyclopalladation of the coordinated phosphine could next be performed by treatment of its eta(1)-P binuclear dimer with silver(I) hexafluorophosphate(V) in a dichloromethane/water mixture followed by treatment with lithium chloride, giving rise to a pair of optically pure enantiomeric dimers with [alpha](D) -322 and +319 degrees in CH(2)Cl(2). Despite the possibilities of the phosphine to attain a five- membered structure by ortho-palladation or a six-membered ring formation by aliphatic C-H bond activation, only the former was observed. X-ray crystallographic data of the meso dimer and an acetylacetonate derivative indicated that the phosphapalladacycle alpha-C methyl substituent was axially located. The 2-D (1)H-(1)H ROESY spectrum of the acetylacetonate derivative further revealed that the phosphapalladacycle was conformationally rigid in CDCl(3). 相似文献
9.
T.E. Vittal Prasad M. Vasavi M. Jyotsna V. Jhansi G. Smitha D.H.L. Prasad 《The Journal of chemical thermodynamics》2008,40(9):1418-1421
Bubble point temperatures (at 95.35 kPa) over the entire composition range were measured for the binary mixtures formed by ethyl benzene with: acetyl acetone, o-, and p-cresols, 1-hexanol, and tetraethoxysilane, employing a Swietoslawski type ebulliometer. Wilson equation was used to represent the measured liquid phase composition versus bubble point temperature data, and the computed values of the vapor phase mole fractions, activity coefficients, and excess Gibbs free energy were tabulated and briefly discussed. 相似文献
10.
McArdle CP Jennings MC Vittal JJ Puddephatt RJ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2001,7(16):3572-3583
Reaction of the flexible dialkynyldigold(I) precursors X(4-C6H4OCH2C-CAu)2 with 1,4-bis(diphenylphosphino)butane gave complexes of formula [[[mu-X(4-C6H4OCH2CCAu)2[mu-(Ph2PCH2CH2CH2CH2PPh2)]]n]. The complexes exist as 25-membered ring compounds with n = 1 when X = O or S, as [2]catenanes with n = 2 when X = CH2 or CMe2, and as a unique doubly braided [2]catenane, containing interlocked 50-membered rings with n = 4 when X = cyclohexylidene. These compounds form easily and selectively by self-assembly; reasons for the selectivity are also discussed. 相似文献