Preservation of electronic properties of double-decker complexes on metallic supports

Single-molecule magnets based on lanthanide double-deckers are attracting significant attention due to their unrivaled single-ion anisotropy. To exploit their fascinating electronic and magnetic properties in devices for information storage or spin transport, studies on the preservation or variation of electronic and magnetic functionalities upon adsorption on surfaces are necessary. Herein, we introduced a comprehensive scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) surface science study, complemented by density functional theory (DFT) simulations, of a recently synthesized single-molecule magnet based on porphyrazine deckers, conveniently equipped with ethyl moieties to make them soluble and sublimable. We demonstrated that the double-decker species were intactly adsorbed on Au(111), Ag(111), and Cu(111) in a flat-on fashion and self-assembled in hexagonal close-packed layers. Systematic multi- and monolayer XPS was performed on the surface-confined species, confirming the preservation of the electronic properties of the ligands and the lanthanide center upon adsorption.

Supramolecular Spangling, Crocheting, and Knitting of Functionalized Pyrene Molecules on a Silver Surface

Pyrenes, as photoactive polycyclic aromatic hydrocarbons (PAHs), represent promising modules for the bottom-up assembly of functional nanostructures. Here, we introduce the synthesis of a family of pyrene derivatives peripherally functionalized with pyridin-4-ylethynyl termini and comprehensively characterize their self-assembly abilities on a smooth Ag(111) support by scanning tunneling microscopy. By deliberate selection of number and geometric positioning of the pyridyl-terminated substituents, two-dimensional arrays, one-dimensional coordination chains, and chiral, porous kagomé-type networks can be tailored. A comparison to phenyl-functionalized reference pyrenes, not supporting the self-assembly of ordered structures at low coverage, highlights the role of the pyridyl moieties for supramolecular crocheting and knitting. Furthermore, we demonstrate the selective spangling of pores in the two-dimensional pyrene assemblies by a distinct number of iodine atoms as guests by atomically resolved imaging and complementary X-ray photoelectron spectroscopy.

Immobilisation of a molecular epoxidation catalyst on UiO-66 and -67: the effect of pore size on catalyst activity and recycling

Amino-functionalised metal-organic frameworks UiO-66 and -67 were post-synthetically modified with salicylaldehyde. A molybdenum complex was immobilised on the resulting materials. They were characterised by (13)C-MAS-NMR, XPS and PXRD to confirm immobilisation and stability. The immobilised complex is an active and reusable catalyst for olefin epoxidation with tert-butyl hydroperoxide (TBHP) as an oxidant. It is shown that the effective pore size, probed with Brunauer-Emmett-Teller (BET) surface area analysis and the number of amino groups affect the diffusion of reactants and products, as well as catalyst recycling.

[Clinical and morphological properties of cold nodules formed in the thyroid gland of patients treated with I-131 for hyperthyreosis]

The authors report on the clinical and morphological features of patients who had been previously treated for toxic adenoma with different doses of 131I isotope, and were then operated on for cold nodule. Progressive pseudoatypic and Hürthle-cell transformations, which are difficult to distinguish from different-type thyroid carcinomas, were revealed in one and a solid anaplastic carcinoma in another of the five patients during histological examination of operative specimens in serial sections. On the basis of these findings the authors support the function-protective operative treatment of single toxic adenomas, although the causal relationship between isotope treatment and consecutive carcinoma can not be verified unanimously.