Liquid-Phase Quasi-Epitaxial Growth of Highly Stable,Monolithic UiO-66-NH2 MOF thin Films on Solid Substrates

High quality, monolithic UiO-66-NH₂ thin films on diverse solid substrates have been prepared via a low temperature liquid phase epitaxy method. The achievement of continuous films with low defect densities and great stability against high temperatures and hot water is proven, clearly outperforming other reported types of MOF thin films.     

A Simple Strategy to Eliminate Hexosylation Bias in the Relative Quantification of N‐Glycosylation in Biopharmaceuticals

N‐glycosylation may affect the safety and efficacy of biopharmaceuticals and is thus monitored during manufacturing. Mass spectrometry of the intact protein is increasingly used to reveal co‐existing glycosylation variants. However, quantification of N‐glycoforms via this approach may be biased by single hexose residues as introduced by glycation or O‐glycosylation. Herein, we describe a simple strategy to reveal actual N‐glycoform abundances of therapeutic antibodies, involving experimental determination of glycation levels followed by computational elimination of the “hexosylation bias”. We show that actual N‐glycoform abundances may significantly deviate from initially determined values. Indeed, glycation may even obscure considerable differences in N‐glycosylation patterns of drug product batches. Our observations may thus have implications for biopharmaceutical quality control. Moreover, we solve an instance of the problem of isobaricity, which is fundamental to mass spectrometry.     

Identification of Semiconductive Patches in Thermally Processed Monolayer Oxo‐Functionalized Graphene

The thermal decomposition of graphene oxide (GO) is a complex process at the atomic level and not fully understood. Here, a subclass of GO, oxo‐functionalized graphene (oxo‐G), was used to study its thermal disproportionation. We present the impact of annealing on the electronic properties of a monolayer oxo‐G flake and correlated the chemical composition and topography corrugation by two‐probe transport measurements, XPS, TEM, FTIR and STM. Surprisingly, we found that oxo‐G, processed at 300 °C, displays C?C sp³‐patches and possibly C?O?C bonds, next to graphene domains and holes. It is striking that those C?O?C/C?C sp³‐separated sp²‐patches a few nanometers in diameter possess semiconducting properties with a band gap of about 0.4 eV. We propose that sp³‐patches confine conjugated sp²‐C atoms, which leads to the local semiconductor properties. Accordingly, graphene with sp³‐C in double layer areas is a potential class of semiconductors and a potential target for future chemical modifications.     

Vibrational Properties of LiGaO2 (II). Theoretical Model Considerations

On the basis of the correlation method and of a simplified version of the extended Keating model with bond-bending forces neglected sphalerite- and chalcopyrite-like modes can be identified in the lattice vibration spectrum of LiGaO₂. In agreement with recently published results for LiInTe₂ it is found that the Li O bond is considerably weaker than the Ga O bond.     

High-temperature heat capacity,thermodynamic properties and debye temperature of CuGe2P3

The heat capacity at constant pressure of CuGe₂P₃ is measured in the temperature range from 180 to 550 K. Standard enthalpies and entropies relative to 298.15 K are calculated from the heat capacity data. The Debye temperature in the high-temperature limit is estimated to be about 710 K.     

Thermal expansion anisotropy and individual bond expansion coefficients in ternary chalcopyrite compounds

The individual bond expansion coefficients of the A^IIB^IVC and A^IB^IIIC₂^VI chalcopyrite compounds are calculated from the principal linear thermal expansion coefficients of the lattice parameters using the regular B C tetrahedron model and a model with a temperature independent free parameter of the lattice. It is shown that the bond expansion coefficients derived from the latter model are in better agreement with the trends found for the interatomic forces in the chalcopyrite compounds and observed for the thermal expansion coefficients in the binary AC, A^IIC and BC compounds.