Carbides, silicides, germides, stannides and plumbides

8 the nitrogen atom is in a linear environment and can be considered to have a stereochemically inactive lone pair, possibly involved in 7r-interactions. 

Each Si contributes a vacant 34 orbital only one is Aown for clarity 

Propose a bonding scheme for Bu2SiNSi Bu3 (14.8) that is consistent with the experimentally determined stmcture. State clearly what hybridization schemes are appropriate. 

Classifying carbides is not simple, but some useful categories are  

Examples of saline carbides are Be2C (see Section 12.4 and eq. 12.14) and AI4C3, both made by heating the constituent elements at high temperatures. Although their solid state structures contain isolated C centres which are converted to CH4 on reaction with H2O, it is unlikely that the C ion is present, since the interelectronic repulsion energy would be enormous. 

Equations 13.30 and 13.31 show syntheses of Na2C2, Ag2C2 and CU2C2 the group 11 carbides are heat- and shock-sensitive, and explosive when dry. 

Carbides containing [C=C=C] are rare they include Mg2C3 (see end of Section 11.4) which liberates propyne upon hydrolysis. 

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Chapter 13 Carbides, silicides, germides, stannides and plumbides 357... 

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