Journal Covers

The cover shows a scanning electron micrograph of vaterite crystals formed by the sea squirt Herdmania momus. These are the largest single crystals of vaterite ever observed, including biogenic, geologic or synthetic vaterite. Flat crystal faces are uncommon in biogenic crystals, but these crystals are clearly hexagonal pyramids. Pokroy et al. show that these crystals have smooth fracture surfaces; thus, they most likely formed ion-by-ion, rather than by attachment of particles. Narrowly distributed orientations and lack of organics at crystal interfaces suggest a new mechanism of biomineral crystal growth, perhaps spherulitic growth from solution. Read more »

Organic electronics have emerged into a highly interesting field of research with a great variety of applications. P. Müller-Buschbaum and co-workers demonstrate the importance of in situ investigations during the printing process of organic electronics. In situ grazing-incidence wide-angle x-ray scattering is used to follow the crystallization process of highly conductive PEDOT:PSS polymer mixtures. These findings are important for tuning transparent polymeric electrodes for organic electronics. Cover Image by Christoph Hohmann, Nanosystems Initiative Munich (NIM). Read more »

In contrast to noninnocent copper corroles and essentially innocent gold corroles, silver corroles appear to be poised on a knife-edge between the two electronic-structural descriptions. The summit trail of Mount Sir Alexander, a peak of the Canadian Rockies described by mountaineer Chris Goulet as a knife-edge that only a mouse can walk on, provides anRead More Read more »

Profound bias- and time-dependent changes in the electronic structure of graphene-based supercapacitor electrodes are demonstrated under operating conditions via a combination of in operando x-ray spectroscopy and ab initio modeling by J.R.I. Lee and co-workers. The evolution in electronic structure reflects changes in the surface chemistry and morphology induced by polarization of the electrode-electrolyte interface and points to distinct pseudocapacitive and electric-double-layer capacitive channels for charge storage. Read more »

Work featured on Applied Optics cover from ALS Beamline 11.3.2. Field-dependent wavefront aberration distribution of an extreme ultraviolet single-lens zone-plate microscope, recovered by the gradient descent algorithm customized for partially coherent imaging and targeted for fast and accurate retrieval. Read more »

The synthesis and structural characterization of a diboryl triaryloctabromocorrole complex fills in a missing link in the family of diboron porphyrinoids. DFT calculations suggest that a strongly electron-withdrawing corrole ligand is required to stabilize the diboryl complex relative to the partially hydrolyzed diboron corrole complexes previously observed. New monoboryl corrole complexes are described, which do not have counterparts in porphyrin chemistry and are stabilized by internal F···H hydrogen bonding. Read more »

Platinum has been inserted into corroles for the first time and three oxidized PtIV(corrole˙2−)ArAr′ complexes have been structurally characterized. The Soret maxima of these complexes exhibit an unusually strong dependence on the meso-aryl substituents on the corrole, indicating aryl → corrole˙2− charge transfer character in these transitions. Read more »

Nacre–the iridescent inner lining of many mollusk shells– has a unique strcuture that is remarkably resistant to fracture. The nacre featured on this cover is from Haliotis laevigata with average layer thickness 470-nm. The colors represent crystal orientationthe crystal lattice tilts across tablets.left stack all tablets are yellow, hence all aragonite crystals are co-oriented. Read more »