The self-assembly of chiral depsipeptide dendrons 4, which contain a cyanuric acid building block at their focal point, with the homotritopic Hamilton receptor 1 is reported. The 1:3 compositions of the resulting chiral supramolecular dendrimers, the association constants K(n), and the cooperativity of binding expressed by Scatchard plots and the Hill coefficients n(H) was determined by NMR titration experiments. The most pronounced positive cooperativity was found for the complexes 1 L(3) with L being the second-generation dendrons 4 c-e. The least stable complexes are formed with the bulky third-generation dendrons 4 f-h. Similar results are obtained by the corresponding complexation of the achiral Frechét-type first- to third-generation dendrons 3 with 1. Chiroptical investigations of 1:3 complexes of 1 and 4 reveal chirality transfer from the dendron to the Hamilton receptor as demonstrated by the appearance of new CD absorption bands at 310 nm.

Simply mixing a core (black) with defined amounts of branching units (red) and end caps (blue) leads to programmed complete self‐assembly of supramolecular dendrimers through complimentary and multiple hydrogen bonding.

Einfaches Mischen eines Kernbausteins (schwarz) mit definierten Mengen an Verzweigungseinheiten (rot) und Endstücken (blau), die jeweils komplementär sind und durch mehrfache Wasserstoffbrücken miteinander verknüpft werden, führt zu einem programmierten Selbstaufbau von supramolekularen Dendrimeren.

Current-voltage curves of small area hysteretic intrinsic Josephson junctions, for which the Josephson energy $E_J=\hbar J_c/2e$ is of order of thermal energy $kT$, are investigated. A non-monotonic temperature dependence of the switching current is observed and explained by thermal phase fluctuations. At low temperatures premature switching from the superconducting into the resistive state is the most important effect of fluctuations. At high temperatures only a single resistive branch is observed. At the cross-over temperature a hysteretic phase-diffusion branch exists. It shows the importance of a frequency-dependent impedance of an external circuit formed by the leads.Comment: 8pages, 14figures, submitted to Phys. Rev.

The dependence of the first critical field of long linear and annular Josephson junctions on the width of the surrounding stripline, the so called idle region, is investigated experimentally. The stripline modifies the effective Josephson length eff in the junction. The experimental data are compared with the theory by Caputo et al. ͓J. Appl. Phys. 85, 7291 ͑1999͔͒ and good agreement is found. The dependence of the first critical field on the width of the surrounding stripline can be well explained using the same eff for both annular and linear junctions.