Enthalpies and entropies of sublimation of tetraphenyl silane and hexaphenyl disilane. The bond dissociation energies of SiC and SiSi

Engineering Reactions in Crystalline Solids: Predicting Photochemical Decarbonylation from Calculated Thermochemical Parameters

“…The calculated radical stabilization energies for primary, secondary and tertiary enol radicals ( R2a − R2c ), increase from −8.90 to −15.07 up to −19.79 kcal/mol, respectively. These values are in excellent agreement with expectations 15,16 that we previously formulated from published experimental and computational data …”

The Role of Precursor‐Decomposition Kinetics in Silicon‐Nanowire Synthesis in Organic Solvents

“…The alkyl‐ and aryl‐substituted organosilanes exhibit qualitatively different reactivities at approximately 450 °C. The SiC bonds in the alkyl‐substituted silanes have lower dissociation enthalpies than those in the aryl‐substituted silanes;20, 21 however, the aryl‐substituted silanes can undergo disproportionation reactions of the type shown in Scheme , and therefore the aryl group is a more reactive substituent under the nanowire growth conditions 22. 23 Although the exact details of the disproportionation reactions have not been well‐studied,24 the mechanism appears to be associative and involves the exchange of a hydrogen atom and a phenyl group.…”

“…To put these findings into perspective, low‐melting‐point metals, such as In and Bi, have recently been used successfully as seeds to lower the metal/semiconductor eutectic temperature to below 300 °C and enable conventional solvents to be used in the VLS method for the growth of nanowires composed of materials such as GaAs,30 InN,31 and CdSe 32. For silicon nanowires, germanium nanowires, and carbon nanotubes,33 however, the use of low‐melting‐point metals to lower the eutectic temperature is not a viable option because of the limited precursor reactivity for Group IV materials—even silane barely decomposes at approximately 350 °C 21. Therefore, despite the technical challenges of high‐pressure and high‐temperature conditions, SFLS has an important role as a general synthetic technique for the synthesis of Group IV semiconductor nanowires.…”

Gas–solvent and water–solvent partition coefficients of the tetraphenyl compounds of group (IV)

“…There are a few solubilities of Ph 4 Si in solvents available, [18][19][20] see Table 4, but there is a considerable discrepancy between the only two reports of the vapor pressure and sublimation enthalpies of Ph 4 Si, those of Calle and Kana'an 24 and of McCauley and Smith. 25 Data from the former workers lead to log C g = À13.85 and DH o vap = 150.0 kJ mol À1 , whereas data from the latter workers gives log C g = À8.06 and DH o vap = 51.0 kJ mol À1 all at 298 K. We regard the results of Calle and Kana'an 24 as much more reasonable and it is their values that we take. Then the values of log C s can be converted to log K s using À13.85 as log C g , see Table 4.…”