Solid-state thermolysis

On the basis of these redox potentials it seems likely that direct electron release to the benzenediazonium ion takes place only with iodide. This corresponds well with experience in organic synthesis iodo-de-diazoniations are possible without catalysts, light, or other special procedures (Sec. 10.6). For bromo- and chloro-de-di-azoniations, catalysis by cuprous salts (Sandmeyer reaction, Sec. 10.5) is necessary. For fluorination the Balz-Schiemann reaction of arenediazonium tetrafluoroborates in the solid state (thermolysis) or in special solvents must be chosen (see Sec. 10.4). With astatide (211At-), the heaviest of the halide ions, Meyer et al. (1979) found higher yields for astato-de-diazoniation than for iodo-de-diazoniation, a result consistent with the position of At in the Periodic System. It has to be emphasized, however, that in investigations based on measuring yields of final products (Ar-Hal), the possibility that part of the yield may be due to heterolytic dediazoniation is very difficult to quantify. 

The trimeric indium antimonide single-source precursor [Et2InSb(SiMe3)2]3, prepared from Et2InCl and Sb(SiMe3)3, was shown in a preliminary study to form InSb nanocrystals (average particle size 10 nm) by solid-state thermolysis at 400 °C under a static vacuum. However, the particles were contaminated with elemental indium.399... 

GaAs Solid-state thermolysis of [Et2Ga As(SiMe3)2 ]2 at 400 °C 9.0 397... 

GaPxSb x Solid-state thermolysis of [(Me3Si)2P(/r-GaEt2)2Sb(SiMe3)2] 9.3 398... 

InSb Solid-state thermolysis of [Et2In Sb(SiMe3)2 ]3 at 400 °C 10.0 399... 

Methatesis of Cd N(Me3Si)2 2 4- SCNR in the presence of TOPO Solid-state thermolysis Cd(SeSiMe3)2 1.5-2.0 394 394... 

ArNHj remains (as it is a weak base), but the concentration is low enough to prevent as yet undiazotised amine undergoing a coupling reaction with the first formed ArNj p. 147). Aromatic diazonium chlorides, sulphates, nitrates, etc., are reasonably stable in aqueous solution at room temperature or below, but cannot readily be isolated without decomposition. Fluoroborates, ArN2 BF4 , are more stable (cf. stabilising effect of BF on other ion pairs, p. 136) and can be isolated in the dry solid state thermolysis of the dry solid is an important preparative method for ffuoroarenes ... 

For the preparation of metal phosphate ceramics by solid-state thermolysis [99, 117, 118] or for the preparation of thin films by CVD [110]... 

The CVD decomposition behavior of binuclear [Pd2(PMe3)6](hfac)2 involves the disproportionation shown in equation 3 . Solid-state thermolysis (140 °C, vacuum) of [Pd2... 

Solid-state thermolysis of 1 -alkyl-2,4-bipyridinium palladium complexes gave cyclometallated complexes [PdCl2(2,4 -R-bipy-H)] (R = H, Me, Bu, CsHu, CgHi, or C10H21) in quantitative yield. ... 

The solid-state thermolysis reactions of the tetra(ammino) complexes, [Pt(NH3)4]X2, proceed similarly, for example. Scheme 1.4 ... 

The ease of amine displacement from cationic complexes depends upon the nature of the anionic counterion. It has been shown33 that the solid. state thermolysis of cationic platinum(II) complexes is sensitive to the nature of the counterion, Eq. 12.14 ... 

Solid-state thermolysis of [PtMe( -allyl)(PPh3)] produced propane and methane. In contrast, oxidation in THF led to simple elimination of 1-butene. [PdX(Me)2(CH2Ph)(bipy)] (X = F, Cl, I, Nj, NCS) showed a thermochemical preference for elimimination of ethane over that of ethylbenzene.Ethane is also spontaneously lost from [ tris(pyraolyl) methane Pd(Me)2(R)]-"X- (R = benzyl, > -allyl, X = I, Br).< >... 

Polymer derived ceramics have been known for the last four decades and are prepared via solid-state thermolysis of preceramic polymers. They exhibit a unique combination of remarkable properties due to their covalent bonding and amorphous nature. Thus, silicon oxycarbide (SiOC) and silicon carbonitride (SiCN) based ternary PDCs have been shown to possess outstanding high-temperature properties such as stability with respect to crystallization and decomposition, oxidation and corrosion resistance as well as excellent thermomechanical properties (e.g., near zero steady state creep resistance up to temperatures far beyond 1000 °C). Their properties are directly influenced by the chemistry and the architecture of the preceramic precursors, thus there is an enormous potential in tuning the microstructure and properties of the PDCs by using tailored polymers. Furthermore, suitable chemical modification of the preceramic precursors leads to quaternary and multinary ceramics, as it has been shown for instance for silicon boron carbonitride ceramics in the last 25 years, which in some cases exhibit improved properties as compared to those of the ternary materials. 

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