Silicon metal atom reactions with

The reactivity of the metal is seen to decrease down the group with silicon metal atoms reacting with water on cocondensation to form the HMOH molecule, whereas lead does not react even on photolysis. Ge and Sn are intermediate cases in which reaction occurs on photolysis. Both the metal atom and metal dimer are observed to undergo a similar insertion reaction of the metal into the H-0 bond of water as previously found for the Group IIIA... 

Dihydro-lH-l,5,2-azasilaboroles derive from the 2,5-dihydro-lH-l,2-aza-boroles ( 6.5.3.3) by substitution of the carbon neighboring N by a silicon atom. They may act as four-electron donors using electron density from the C=C double bond and the N atom. The B atom behaves as an acceptor center. Two pathways are known for complex synthesis reaction with a generated transition-metal complex fragment and reaction with metal atoms by the metal-vapor synthesis method. 

In principle this section can be divided into two parts. The first one deals with the matrix isolation of various silicon oxides whereas reactions of such oxides with metal atoms are presented in the second part. 

Apart from the metal atom aggregation reactions described below, bis(arene)metal complexes of the early transition metals are resistant to ligand displacement The rings on the corresponding bis(naphthalene)metal species (41) are by, contrast, labile. Polymer-supported analogs of these naphthalene compounds with vanadium and chromium are known (42), but Ti atoms attack the polymer at the silicon ether linkage. These and other hybrid polymers can be further modified once the metal atom is incorporated. Thus a-methyl naphthalene is displaced from the hybrid organometallic polymer shown in Scheme 7 (43). 

Altogether, the reaction with CO demonstrates impressively the overloaded-underloaded principle, mentioned at the begiiming. The imsaturated silicon atom is, on the one hand, coordinatively underloaded. This, at first, makes the reaction with CO possible (catalytic processes at the centre of transition metal complexes). On the other hand, the overloaded supersilyl group shields the unsaturated silicon atom and therefore lays open the reactivity of the latter atom against CO. In normal cases, other reactions wiiich will be operative never give the adduct formation with CO a chance. 

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