The present invention relates to an electronic device comprising anode, cathode and at least one organic layer which comprises a compound of the formula (I) to (IV). The invention furthermore encompasses the use of compounds of the formula (I) to (IV) in an electronic device and to a compound of the formula (Ic) to (IVc).

Materials for electronic devices

In this Perspective, we highlight the main challenges to be addressed in the development of heterogeneous catalysts for the direct functionalization of methane. Along with our personal view on current developments in this field, we outline the main mechanistic, engineering, and catalyst design issues that have hampered implementation of new technologies and highlight possible paths to overcome these problems.

Strategies for the direct catalytic valorization of methane using heterogeneous catalysis:challenges and opportunities

NSFC of China [21133010, 21203215, 51221264, 21261160487]; MOST [2011CBA00504]; Strategic Priority Research Program of the Chinese Academy of Sciences [XDA09030103]

Electron microscopy of solid catalysts--transforming from a challenge to a toolbox

Density functional calculations yield energy barriers for H abstraction by oxygen radical sites in Li-doped MgO that are much smaller (12±6 kJ mol−1) than the barriers inferred from different experimental studies (80–160 kJ mol−1). This raises further doubts that the Li+O.− site is the active site as postulated by Lunsford. From temperature-programmed oxidative coupling reactions of methane (OCM), we conclude that the same sites are responsible for the activation of CH4 on both Li-doped MgO and pure MgO catalysts. For a MgO catalyst prepared by sol–gel synthesis, the activity proved to be very different in the initial phase of the OCM reaction and in the steady state. This was accompanied by substantial morphological changes and restructuring of the terminations as transmission electron microscopy revealed. Further calculations on cluster models showed that CH4 binds heterolytically on Mg2+O2− sites at steps and corners, and that the homolytic release of methyl radicals into the gas phase will happen only in the presence of O2.

Sites for Methane Activation on Lithium-Doped Magnesium Oxide Surfaces†

/pdf/heterogene-katalysatoren-fundamental-betrachtet-4enuot7bcl.pdf

Heterogene Katalysatoren – fundamental betrachtet

ODMR and ODENDOR spectra were obtained for quinoxaline and p-dichlorobenzene in their excited triplet states. These molecules were studied in mixed crystals using heavy atom containing hosts. For protons the complete hyperfine tensors could be evaluated, yielding information about the symmetry and geometry of these molecules in their triplet states. For quinoxaline no deviations from planarity have been observed whereas triplet p-dichlorobenzene turned out to be non-planar. The measured π-spin densities in p-dichlorobenzene confirm the 3B1u symmetry of this molecule in its first excited triplet state.

ODMR and Proton-ENDOR investigations of the symmetry and geometry of the lowest excited triplet state of quinoxaline and p-dichlorobenzene at high magnetic fields

Defect rich MgO nanocrystals arranged in a hierarchic three-dimensional pore network were synthesized by using gel combustion synthesis (GCS). By adding Li to the combustion precursor, Li-induced changes in the morphology and defect structure of MgO could be studied systematically. At low Li loadings (up to 1 wt %), the three-dimensional pore network was resistant to temperatures up to 800 °C, even though the primary MgO nanoparticles had changed their morphology from on average 8 nm size {100} terminated nanocubes to up to 250 nm large complex polyhedral, exposing more and more {111} facets. At higher Li loadings, the primary MgO particles grow even further, to up to 500 nm, causing the three-dimensional pore network to collapse. After describing the GCS method, detailed structural characterizations of all of the materials synthesized were conducted by means of XRD, BET and pore size analysis, and electron microscopy. IR and thermogravimetric mass spectroscopy (TG-MS) in combination with XRD were used to investigate the formation and decomposition of carbonate species during synthesis and calcination. Diffuse reflectance UV/Vis (DR-UV/Vis) spectroscopy was used to characterize surface defects, such as low coordinated O2− ions at edges, corners, and kinks of the MgO surface. Bulk defects were studied by using electron paramagnetic resonance (EPR) spectroscopy. Morphology and defect concentration of the Li/MgO materials were found to be strongly dependent on the fuel-to-oxidizer ratio used in the combustion synthesis, the Li concentration, and the calcination atmosphere.

K.-P. Dinse

Papers

ODMR and Proton-ENDOR investigations of the symmetry and geometry of the lowest excited triplet state of quinoxaline and p-dichlorobenzene at high magnetic fields

Lithium as a Modifier for Morphology and Defect Structure of Porous Magnesium Oxide Materials Prepared by Gel Combustion Synthesis

Observation of quadrupole splittings of organic radicals in solution by endor in liquid crystals

Untersuchung der π-σ-delokalisation an den radikalionen des rubrens mit endor in lösung

Fluorine and proton ENDOR of aromatic radicals in solution