This tutorial review highlights the methods for the preparation of metal modified precursor derived ceramics (PDCs) and concentrates on the rare non-oxide systems enhanced with late transition metals. In addition to the main synthetic strategies for modified SiC and SiCN ceramics, an overview of the morphologies, structures and compositions of both, ceramic materials and metal (nano) particles, is presented. Potential magnetic and catalytic applications have been discussed for the so manufactured metal containing non-oxide ceramics.

Lithiated 4‐methyl‐2‐[(trimethylsilyl)amino]pyridine (ApTMSH) undergoes a salt metathesis reaction with [ScCl3(thf)3] and FeCl3, at low temperature in thf, to yield the homoleptic complexes [Sc(ApTMS)3] (1) and [Fe(ApTMS)3] (2). An analogous reaction with MnCl2, CoCl2 and FeCl2 using two equivalents of 4‐tert‐butylpyridine (tBuPy) as additional donor ligand affords the structurally analogous cis complexes [Mn(ApTMS)2(tBuPy)2] (3), [Co(ApTMS)2(tBuPy)2] (4) and [Fe(ApTMS)2(tBuPy)2] (5). If FeCl2 is used without tBuPy, the highly symmetric trinuclear complex [Fe3(ApTMS)6Li2O] (6) is obtained. Furthermore, the use of ZnCl2 in a reaction with lithiated ApTMSH yields the dimeric complex [Zn2(ApTMS)4] (7) in which two ApTMS ligands bridge the two metals. All complexes have been characterised by X‐ray crystal structure analysis. To the best of our knowledge, complexes 1 and 2 and 5 are the first scandium and iron aminopyridinates, respectively, and complex 3 is the first manganese aminopyridinate complex which contains no additional anionic ligand. Complexes 4 and 7 are rare examples of cobalt and zinc aminopyridinates. This study proves that aminopyridinato ligands are highly universal ligands since they are able to stabilize early and late transition metals. Aminopyridinates of every first row transition metal are now available. The magnetic properties of all paramagnetic complexes were investigated. All complexes are high‐spin complexes and the trinuclear iron complex 6 exhibits a weak antiferromagnetic coupling.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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Two series of co-polymers with the general formula [B(CHSiCH(NH)(NCH))], i.e., composed of CHSiCH(NH) and CHSiCH(NCH) (CH = CHCH, CHCH) building blocks in a well defined x : y ratio, have been synthesized by hydroboration of dichloromethylvinylsilane with borane dimethyl sulfide followed by successive reactions with lithium amide and methylamine according to controlled ratios. The role of the chemistry behind their syntheses has been studied in detail by solid-state NMR, FT-IR and elemental analyses. Then, the intimate relationship between the chemistry and the melt-spinnability of these polymers was discussed. By keeping x = 0.50 and increasing y above 0.50, i.e., obtaining methylamine excess, the co-polymers contained more ending groups and especially more tetracoordinated boron, thus allowing tuning very precisely the chemical structure of the preceramic polymer in order to meet the requirements for melt-spinning. The curing treatment under ammonia at 200 °C efficiently rendered the green fibers infusible before their subsequent pyrolysis under nitrogen at 1000 °C to generate Si-B-C-N ceramic fibers. Interestingly, it could be possible to produce also low diameter hollow fibers with relatively high mechanical properties for a further exploration as membrane materials.

We synthesized nickel (Ni) nanoparticles (NPs) in a high specific surface area (SSA) p-block element-containing inorganic compound prepared via the polymer-derived ceramics (PDC) to dispatch the obtained nanocomposite towards oxygen...

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The processing of nonwoven porous ceramics by combining the polymer‐derived ceramic (PDC) route with electrospinning offers an excellent strategy for developing new porous ceramic structures. Currently, the manufacturing of nonwoven porous materials from preceramic polymers is conducted by trial and error approaches. The necessity to predict the e‐spinnability conditions from properties assessment offers a potential tool to control the manufacture and the resulting material morphology. This work assesses the relationship between the preceramic polymer solutions and the resulting electrospun nonwoven morphology. For this, a commercially available liquid oligosilazane (Durazane 1800) is selectively cross‐linked to achieve a reliable and spinnable preceramic polymer (HTTS), which is then dissolved in tetrahydrofuran (THF). Based on the investigation of the rheological behavior of various polymer concentrations, three different polymer solution regimes (diluted, semidiluted, and concentrated) are identified and correlated with the resulting morphology of the e‐spun material (spherical particles, beaded fibers, and seamless fibers). After the pyrolysis, the nonwoven ceramics manufactured from the solution with 65 wt% of HTTS is converted to a SiCN ceramic nonwoven with 86% of open porosity, profiling as a promising candidate for developing high‐performance filter systems and catalytic supports in harsh environments.

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