A red‐brown zirconium nitride was prepared by ammonolysis of ZrCl4. Chemical analysis leads to a composition of Zr3N4. It is not possible to distinguish between the space groups Pnam and Pna21 in the case of Zr3N4 using powder methods. The lattice constants are: a = 972.94(5) pm, b = 1081.75(6) pm, c = 328.10(1) pm (Z = 4). X‐ray powder diffraction data were used for structure refinement. The high temperature behavior was investigated with in situ XRD methods. Zr3N4 decomposes into ZrN and nitrogen gas at temperatures above 800°C.

Evolved gas analysis (EGA) from thermal analyzers such as thermogravimetry (TG) or simultaneous thermal analysis (STA) which refers to simultaneous TG-DSC is well established since it greatly enhances the value of TG or TG-DSC results. The sensitive and selective FT-IR technique is in particular useful for the analysis of organic molecules but also for infrared active permanent gases evolved during most decomposition processes. The coupling interface between thermal analyzers and FT-IR spectrometers usually consists of heated adapters and a flexible, heated transfer line. In this work, a novel direct coupling of an STA instrument and an FT-IR spectrometer without a transfer line is presented. A very small FT-IR spectrometer is directly mounted on top of the STA furnace leading to a compact and fully integrated STA-FT-IR coupling system. The possibilities and the value of simultaneous STA-FT-IR measurements are demonstrated for organic, biomass, and ceramic samples in the temperature range between room temperature and about 1,500°C. Various samples from the field of inorganics and organics-especially polymers-were furthermore measured showing the advantages of the direct STA-FT-IR coupling compared to state-of-the-art STA-FT-IR coupling using a heated transfer line: we found that the time delay caused by the volume of the transfer line itself is rather negligible whereas a significantly better correlation between gas detection and TG results was observed in case of some highly condensable decomposition gases. Aspects of quantification of evolved gases are furthermore discussed as well as the known nonlinearity of FT-IR detection at higher gas concentrations.

Organosilsesquioxane hybrid materials are an important class of functional materials due to their tailorable functions and high thermal and optical stability. Recently, several studies showed that phenyl-substituted trialkoxysilanes can be converted into reversibly melting gels by applying hydrolysis and condensation reactions. We studied the underlying mechanisms of their formation and the final structure in detail by a combination of various spectroscopic techniques, thermal analysis, size exclusion chromatography, and X-ray diffraction. Our investigations reveal that local ladder-type silsesquioxanes with a defect-rich structure are formed in a first hydrolysis and condensation step. The partial presence of stable −OH and methoxy groups attached to the aryl-substituted silicon atoms in the ladderlike polymer explains their thermoplastic behavior. Heating above a particular consolidation temperature leads to further condensation reactions of the residual groups as well as a structural reorientation of the ladder-type polymers. The final materials are hard and cross-linked hybrid glasses with thermal stability higher than 400 °C and high optical transparency.

Single crystals of disilver(I) monofluorophosphate(V), Ag2PO3F (1), were obtained by slow evaporation of a diluted aqueous Ag2PO3F solution. Compound 1 adopts a new structure type and crystallizes in the monoclinic space group C2/c with eight formula units and lattice parameters of a = 9.2456(8) A, b = 5.5854(5) A, c = 14.7840(13) A, and beta = 90.178(2) degrees. The crystal structure of 1 [R(F2 > 2sigma(F2) = 0.0268, wR(F2 all) = 0.0665] is composed of three crystallographically independent Ag+ cations and PO3F2- anions as single building units. The oxygen environment around each of the Ag+ cations is different, with one Ag+ in distorted octahedral (d(Ag-O) = 2.553 A), one in nearly rectangular (d(Ag-O) = 2.445 A), and one in distorted tetrahedral (d(Ag-O) = 2.399 A) coordination. Additional Ag-F contacts to more remote F atoms located at distances >2.80 A augment the coordination polyhedra for the two latter Ag+ cations. The monofluorophosphate anion deviates slightly from C3v symmetry and exhibits the characteristic differences in bond lengths, with a mean of 1.510 A for the P-O bonds and one considerably longer P-F bond of 1.575(2) A. Compound 1 was further characterized by vibrational spectroscopy (Raman and IR) and solid-state 19F, 31P, and 109Ag MAS NMR spectroscopy. The value for the isotropic one-bond P-F coupling constant in 1 is 1JPF = -1045 Hz. Thermal analysis (TG, DSC) revealed a reversible phase transition at 308 degrees C, which is very close to the decomposition range of 1. Under release of POF3, Ag4P2O7 and Ag3PO4 are the thermal decomposition products at temperatures above 450 degrees C.

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