A chiral cyclophane–type macrocycle bearing two thiol groups has been prepared by chemical modification of S,S-(+)-tetrandrine. Cleavage of p-nitrophenyl acetate by deprotonated form of this macrocycle proceeds with a rate constant expected for a simple thiol anion of similar basicity, but the reactivity toward p-nitrophenyl esters of N-protected amino acids is one order of magnitude higher tha...

Concise synthesis of 1,2,4-oxadiazoles was achieved by heating N-benzyl amidoximes with K3PO4 in DMF at 60 °C under an O2 atmosphere via benzylic C-H oxygenation. On the other hand, aerobic treatment of N-benzyl amidoximes with Cs2CO3 in DMSO at 100 °C could result in oxidative skeletal rearrangement to deliver quinazolinones as a major product. This orthogonal product selectivity could be real...

Nucleic acids can undergo dynamic conformational changes associated with the regulation of biological processes. A molecule presenting larger affinities for alternative structures relative to a duplex is expected to modify such conformational equilibria. We have previously reported that macrocyclic bis-acridine binds preferentially to single-stranded regions, especially DNA hairpins, due to ste...

The synthesis and characterization of some new binuclear copper (II) complexes, based on the use of large, pyrole-containing macrocycles, the so called "expanded porphyrins", [Cu2(macrocycle)]+4 is described. Electron Spin Resonance (ESR) studies indicate a weak "half-field line", which is characteristic of the Cu(II)-Cu(II) dimer, is observed at about 1600G. The obser...

The asymmetric unit of the title compound, Cs(2)[Co(CH(4)O(6)P(2))(2)(H(2)O)(2)], is comprised of one bidentate methyl-enediphospho-nate ligand and one water mol-ecule which are coordinated to the Co(II) atom, as well as a caesium counter-cation. The Co atom occupies a special position on a crystallographic inversion center. The caesium ion is octa-hedrally coordinated by six O atoms with Cs-O ...

The synthesis of a peptide-containing lasso molecular switch by a self-entanglement strategy is described. The interlocked rotaxane molecular machine consists of a benzometaphenylene[25]crown-8 (BMP25C8) macrocycle surrounding a molecular axle. This molecular axle contains a tripeptidic sequence and two molecular stations: a N-benzyltriazolium and a pH-sensitive anilinium station. The tripeptid...

Engineering self-templating inorganic architectures is critical for the development of bottom-up approaches to nanoscience, but systems with a hierarchy of templates are elusive. Herein we describe that the cluster-anion-templated (CAT) assembly of a {CAT}⊂{Mo24 Fe12 } macrocycle forms a giant ca. 220 nm(3) unit cell containing 16 macrocycles clustered into eight face-shared tetrahedral cluster...

A rotaxane is described in which a macrocycle moves reversibly between two hydrogen-bonding stations after a nanosecond laser pulse. Observation of transient changes in the optical absorption spectrum after photoexcitation allows direct quantitative monitoring of the submolecular translational process. The rate of shuttling was determined and the influence of the surrounding medium was studied:...

An inhomogeneous differential equation method is used to calculate the Rayleigh and Raman scattering cross sections for atomic hydrogen and atomic caesium as functions of wavelength below and above the ionization limits. The profile of the scattering cross section near the 6s-6p resonance of atomic caesium is determined by including an energyindependent radiative width in the scattering formula...

In the title compound, C42H42N4O2, the complete molecule is generated by a crystallographic inversion centre. The porphyrin system exhibits a near planar macrocycle conformation with an average deviation from the least-squares plane of the 24 macrocycle atoms of 0.037 (5) Å. The phenyl ipso C atoms are positioned above and below the porphyrin plane by 0.35 (1) Å and the macrocycle shows evidenc...