The cyclic voltammetry of some fullerene-ferrocene derivatives shows that these compounds possess very interesting electrochemical properties.

The transition states for methane activation in liquid superacid have been studied by experimentally determined secondary kinetic deuterium isotope effects (SKIEs) and computational chemistry. For the first time, the SKIEs on hydrogen/deuterium exchange of methane have been measured by using the methane isotopologues in homogeneous liquid superacid (2HF/SbF5). To achieve high accuracy of the SKIEs, the rate constants for pairs of methane isotopologues were simultaneously measured in the same superacid solution by using NMR spectroscopy. Density functional theory (DFT) and high-level ab initio methods have been employed to model possible intermediates and transition states, assuming that the superacids involved in the exchange reactions are H2F+ ions solvated by HF. Only the unsolvated superacid H2F+ is found to be strong enough to protonate methane, yielding the methonium ion solvated by HF as a potential energy minimum. In contrast, the (HF)x-solvated H2F+ superacids (x = 1-4) do not appear to be strong enough to yield stable solvated methonium ions. However, such ions show up as parts of the transition states of the exchange in which the methonium ions are solvated by (HF)x. The calculated DFT activation barrier is in good agreement with that experimentally observed.

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The BDII rat is genetically predisposed to estrogen-dependent endometrial adenocarcinoma and represents a valuable model for this type of tumor. Tumors arising in strain crosses involving the BDII rats had previously been screened for DNA copy number changes using comparative genome hybridization (CGH). It was found that extra copies of the proximal region of rat chromosome (RNO) 6 commonly could be detected in these tumors. Based on RH-mapping data and comparative mapping with mouse and human, seven cancer-related genes were predicted to be situated in RNO6q14-q16. Rat PACs were isolated for the N-myc proto-oncogene (Mycn), apolipoprotein B (Apob), the DEAD box gene 1 (Ddx1), ornithine decarboxylase 1 (Odc1), proopiomelanocortin (Pomc1), ribonucleotide reductase, M2 polypeptide (Rrm2), and syndecan 1 (Sdc1). The localization of the genes to the region was verified by FISH (fluorescence in situ hybridization) mapping, and the detailed order among them was determined by dual-color FISH. By Southern blot analysis, it was found that the Mycn locus was highly amplified in two out of 10 cell cultures derived from the tumors. In one of them (designated RUT30), the amplification level of Mycn was estimated at 140x. Two other genes were coamplified (Ddx1 and Rrm2) at much lower levels. Similarly, in another culture (designated RUT2), Mycn was amplified more than 40x, whereas three of the other genes (Ddx1, Rrm2, and Odc1) were coamplified at lower levels. Using FISH on metaphase chromosomes from the cell cultures analyzed, the amplified sequences were shown to be located in typical HSRs. With competitive RT-PCR, distinct overexpression of Mycn and Ddx1 could be demonstrated in both RUT2 and RUT30. In addition, Mycn was overexpressed in two other tumors not exhibiting Mycn amplification. Taken together, our results suggest that overexpression of Mycn plays an important role in the development of endometrial cancer in the BDII rat. In humans, Mycn amplification has been reported mainly from tumors of neuronal origin. To our knowledge, this is the first report of Mycn amplification and overexpression in hormone-dependent tumors.

Protonation of ferrocene has been suggested to take place on carbon (exo-protonation) or iron (endo-protonation). However, experiments have not been conclusive because of interfering exchange reactions. Now low-temperature protonation of ferrocene and [2H10]-ferrocene in superacid and direct observation of the carbocation by 1H NMR at low temperature shows only primary protonation and that it exclusively takes place in an endo-fashion. Studies by DFT calculations using B3LYP hybrid functional indicate the presence of an intramolecular nonlinear C—H—Fe bond and that the proton might be delocalized between carbon and iron. Potential energy barriers for degenerate rearrangements of the hydride bridged carbocation are low, suggesting that the proton might be delocalized between all 10 carbons and iron. The NMR results are consistent with such an interpretation.Key words: regioselective, protonation, superacid, ferrocenonium ion.

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Insight into the detailed mechanism of carbon lithiation by an organolithium reagent and of carbon sodiation by an organosodium reagent has been obtained using [1.1]ferrocenophanyllithium (1) and [1.1]ferrocenophanylsodium (3), respectively. In tetrahydrofuran (THF) 1 and 3 undergo rapid 1,12-proton transfer reactions which are coupled with 1,12-lithium ion and 1,12-sodium ion transfers, respectively. It is concluded that the degenerate rearrangement of 1 does not make use of a pseudorotation mechanism, but occurs by direct conversion of a syn-conformer to another syn-conformer. Activation parameters (ΔH ⧧ = 19 kJ mol-1 and ΔS ⧧ = −93 J K-1 mol-1) for the degenerate reaction of 1 in THF have been measured by dynamic NMR spectroscopy. The primary isotope effect (k H/k D) of the 1,12-hydron transfer is 7.4 ± 1.5 at 320 K. The degenerate rearrangement of 1 shows strong solvent dependence, e.g. the reaction is 4 × 103 times faster in THF than in dimethyltetrahydrofuran (DMTHF). Thus, the rearrangement may be catalyzed by THF in DMTHF. The catalysis is first order in THF at low concentrations of THF. The results show that in the rate-limiting activated complex the lithium ion is coordinating one solvent molecule more than in the initial state. It is paired with a carbanion in which the proton is symmetrically located between the bridge carbons. Compound 3 shows a behavior similar to that of 1, but it is more fluxtional. It also shows a solvent catalysis that is weaker than for 1. It is concluded that 3 also exchanges using an activated complex that contains one solvent molecule more than the initial complex.

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