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Desymmetrized [2]catenanes were synthesized and shown to exhibit excellent translational selectivity. The templated synthesis takes effect from the formation of pseudorotaxanes between pi-rich crown ethers and a pi-deficient pyromellitic (PmI) unit, followed by macrocyclization around the crown ethers with the creation of a bipyridinium (BPy) unit. The crown ethers preferably encircle the BPy unit in the resulting [2]catenanes in both solution and the solid state, as indicated by various spectroscopic analyses.

[Structure: see text] The regioselective functionalization of C60 with a trans-4,trans-4,trans-4 trisaddition pattern is not feasible directly. We have found an indirect approach taking advantage of the modified electronic reactivity of cis-1 bisadducts. The cis-1 addition pattern electronically activates three trans-4 C=C bonds on the opposite hemisphere of C60, allowing further highly regioselective additions at these positions. Thermal removal of the cis-1 blocking unit results in a trans-4,trans-4,trans-4 trisadduct with C3v symmetry.

Complete saturation of a single six-membered ring on fullerene C60 has been achieved. The critical step in this first synthesis of a fully characterized 1,2,3,4,5,6-hexaadduct consisted of a remarkable double 5-exo-trig addition of alkoxyl radicals promoted by lead tetraacetate. Two possible opening pathways ([2 + 2 + 2] retrocycloadditions) for the newly synthesized compound were explored using quantum mechanical calculations. We found that the oxa bridges in the hexaadduct prevent ring opening through the retro[2 + 2 + 2] mechanism due to the high activation barrier and endothermicity of the reaction.

[reaction: see text] Scalar coupling between hydroxyl groups sharing a 1,4- or 1, 3-intramolecular hydrogen bond can be readily detected using standard 2D NMR techniques. Analyses of isotopically perturbed 2D J-resolved spectra have revealed (h2)J to be on the order of 0.3 Hz in systems such as diols 2 and 3. A standard 2D COSY experiment, modified to detect small coupling constants, is shown to be a convenient method for detecting (h2)J in these systems. Couplings derived from density functional finite perturbation theory (DFT/FPT) are found to be in general agreement with experimental data.

Dehydro[24]annulene 1c adopts an unusual planarized conformation in the crystal. A multilayered stack of hydrogen-bonded grids delineates tightly packed nanotubular channels. The related macrocycles 1a and 1b, on the other hand, have the expected puckered conformations in the crystal.

International audience; A triphenylamine-derived pentaaryl fullerene undergoes an unusual oxidative dearylation under basic conditions to give tetraarylated epoxy fullerene in high yield. The structure of the product was confirmed by single crystal X-ray diffraction. A mechanism is proposed to account for the loss of the addend and the subsequent formation of the epoxide group.

Employing well-established template-directed protocols, which depend upon dynamic covalent, coordinative, and noncovalent chemistry for their efficient outputs, we have synthesized, in a convergent manner, Borromeates composed of three identical macrocycles which present, diagonally in pairs, six exo-bidentate bipyridyl ligands and six endo-diiminopyridyl ligands, each carrying either pentenyloxy or p-tolylpentenyloxy substituents on their 4-positions, to six zinc(II) ions.

[reaction: see text] The unusually stable perchloro-2,5,8-triazaphenalenyl radical 1 and its twisted dechlorinated dimer 2 were synthesized and characterized by ESR spectroscopy and X-ray crystallography. The X-ray structure of dimer 2 shows that the double bond connecting the two triazaphenalene systems is strongly twisted. Dimer 2 has a dramatic color shift from the solid state to solution, which may be due to a change of the twisting angle between both states.