Isotopic rules are studied for calculated vibrational frequencies of all possible 7212C/13C isotopomers of the C7 cluster of the C2v symmetry. The isotopomers can undergo 486 isomerizations which are decomposed into 27 subclasses using properties of sums of the squares of the vibrational frequencies.
The labelled compound was prepared by chlorination of [2-14C]acetone obtained from the barium salt of [1-14C]acetic acid by pyrolysis. The reaction product 1,1-dichloro [2-14C]acetone was converted to 2-dichloromethyl-2-methyl [2-14C]-1,3-dioxolane by condensation with ethylene glycol in the presence of thionyl chloride. Radiochemical yield: 62% based on [1-14C]acetic acid.
Authors:P.M. Ghogomu, Elise Provost, M. Bouroukba, M. Dirand, and M. Hoch
The solubility of two n-alkanes in commercial organic liquids, such as diesel fuel and jet fuel represent a problem to industry,
because they precipitate in an unpredictable fashion. First we calculated the metastable enthalpy and entropy of fusion of
the low temperature forms of the n-alkanes. We analyzed the solubility of alkanes n-C22H46, n-C23H48, n-C24H50 and n-C28H58
in ethylbenzene, m-xylene, n-heptane and gas oil. All systems seem to be close ideal, possibly with a slight positive deviation.
We analyzed the solubility at constant temperature of the ternary system solvent C22H46-C24H50, C23H48-C24H50, C13H28-C16H34,
C20H42-C22H46, C20H42-C24H50 and C20H42-C28H58, and looked at cloud points in various ternary systems. When the difference
in the number of carbon atoms in the two alkanes is small, four or less, a metastable solid solution precipitates from the
solvent. If the difference in the number of carbon atoms is six or more, the ‘equilibrium’ phases, or at least phases with
low solubility precipitate.
The yield and average cross section for the reactions11B(p, n)11C,12C(p, )13N,13C(p, n)13N,
C(d, n)13N,14N(p, )11C,16O(p, )13N,16O(d, n)17F,16O(t, n)18F, and18O(p, n)18F have been measured in different compounds. The charged particles were created in the samples themselves either through recoil by scattering of 14 MeV neutrons off hydrogen and deuterium, or by the (n, t) reaction on6Li using thermal neutrons. The yields of reactions12C(d, n);16O(p, );16O(t, n) and18O(p, n) have been measured using proton, deuteron and triton spectra generated by 14 MeV neutrons in the reactions D(n, p)2n;6Li(n, d);7Li(n, d) and10B(n, d);7Li(n, t) and10B(n, t), respectively.
Authors:A. Santana, A. Mauro, H. Zorel, M. Mattioli, and V. de Lucca Neto
The dimeric compound [Pd(bzan)(μ-OOCCH3)]2 (1) (bzan=N-benzylideneaniline) reacts with KX, in methanol/acetone (2:1), affording the analogous dimeric pseudohalogen-bridged species
[Pd(bzan)(μ-X)]2 [X=NCO(2),SCN(3), CN(4)]. The compounds were characterized by elemental analysis, infrared spectroscopy, NMR and thermogravimetric
analysis. IR data for 2–4 showed bands typical of coordinated pseudohalogen ligands clearly indicating the occurrence of the
exchange reaction. Their thermal behaviour was investigated and suggested that their stability is influenced by the bridging
ligand. The thermal stability decreased in the order[Pd(bzan)(μ-CN)]2>[Pd(bzan)(μ-SCN)]2>[Pd(bzan)(μ-OOCCH3)]2>[Pd(bzan)(μ-NCO)]2. X-ray results showed the formation of Pd as final decomposition product.
Authors:Yun Zhou, Guifeng Huang, Xiaolan Li, Feng Chen, Hong Liu, Ying Yang, Zhong Fan, Jinghui Jiang, and Jun Yang
identified as aliphatic, aromatic, and monoterpene compounds were located in the region marked (a)–(c), respectively. Similarly, some components identified as C13-norisoprenoids were located in region (d). The peaks were distributed over the entire
Authors:E. Aragon, K. Jardet, P. Satre, and A. Sebaoun
The Al–Ga–Zn ternary phase diagram presents two isobaric invariant reactions: a eutectic at 231C and a metatectic at 1231C
[1–3]. Calorimetric measurements on the two isobaric invariant reactions have been carried out. First the Tammann method has
enabled us to determine the composition of their limits on five isopletic cross sections. Then, the compositions of the invariant
phases have been determined.
The current experimental and computational research in carbon clusters pointed out a need for enumeration of all possible12C/13C isotopoments of the C2v cyclic odd-numbered carbon clusters Cn. It is shown that the number of the isotopomers is given by 2k–1(2k–1+1) withk=(n+1)/2. Some illustrative computed structure and energy data for the clusters are reported, too.
The set of all 51 possible12C/13C isotopomers of a C8 cluster of D2d symmetry has been studied by means of the harmonic vibration analysis based on the force field resulting from the second order Møller-Plesset (MP2) perturbation treatment with the 6-31G* basis set. The isotopomers can undergo 200 isomerizations which can be classified into 5 distinct groups using the properties of sums of the squares of harmonic vibrational frequencies.
Authors:N. Ishioka, H. Matsuoka, S. Watanabe, A. Osa, M. Koizumi, T. Kume, S. Matsuhashi, T. Fujimura, A. Tsuji, H. Uchida, and T. Sekine
The positron emitters11C,13N and18F and their labeled compounds have been produced for studies on plants using a newly developed positron emitting tracer imaging
system. Although this system covers, at present, a limited area in a plant, the distribution of the positron emitter fed into
the plant can be visualized dynamically. Further development of positron-emitter-labeled compounds is expected to elucidate
the physiological function of plants in vivo.