Swelling Pores: Porosity is a key parameter when selecting materials for catalysts, chemical separations, gas storage, host-guest interactions, and related chemical processes. In most cases the porosity of a material is fixed. Rabone et al. (p. 1053 ; see the Perspective by Wright ) have described a molecular material in which the size of the pores changed during the sorption process. The porosity increased because a dipeptide linker between metal centers reoriented during uptake of some gases, thus improving the capacity of the material to adsorb.

The body-centered cubic A15-structured cesium fulleride Cs ₃ C ₆₀ is not superconducting at ambient pressure and is free from disorder, unlike the well-studied face-centered cubic A ₃ C ₆₀ alkali metal fulleride superconductors. We found that in Cs ₃ C ₆₀ , where the molecular valences are precisely assigned, the superconducting state at 38 kelvin emerges directly from a localized electron antiferromagnetic insulating state with the application of pressure. This transition maintains the threefold degeneracy of the active orbitals in both competing electronic states; it is thus a purely electronic transition to a superconducting state, with a dependence of the transition temperature on pressure-induced changes of anion packing density that is not explicable by Bardeen-Cooper-Schrieffer (BCS) theory.

We investigate the normal state of the ``11'' iron-based superconductor FeSe0.42Te0.58 by angle-resolved photoemission. Our data reveal a highly renormalized quasiparticle dispersion characteristic of a strongly correlated metal. We find sheet dependent effective carrier masses between $\approx${}3\,and\,16me corresponding to a mass enhancement over band structure values of m*/mband$\approx${}6\char21{}20. This is nearly an order of magnitude higher than the renormalization reported previously for iron-arsenide superconductors of the ``1111'' and ``122'' families but fully consistent with the bulk specific heat.