Organosilicon group

Hybrid organosilicon-organophosphazene polymers have also been synthesized (15-18) (structure ) (the organosilicon groups were introduced via the chemistry shown in Scheme 11). These are elastomers with surface contact angles in the region of 106°. Although no biocompatibility tests have been conducted on these polymers, the molecular structure and material properties would be expected to be similar to or an improvement over those of polysiloxane (silicone) polymers. 

Metal Complexes of 77-Ligands Containing Organosilicon Groups, 15, 113 Metal 77-Complexes formed by Seven- and Eight-Membered Carbocyclic Compounds, 4, 353... 

As we showed previously in this chapter, silicon easily expands its valence shell to become a penta-coordinated species. Therefore, it is expected that an intramolecular transfer of organosilicon group from X to Y may occur via a radical mechanism, provided that the R substituents on the silicon atom are not good leaving groups (Reaction 6.20). 

Homolytic 1,5 transfer of an organosilicon group from enoxy oxygen to alkoxy oxygen has also been observed [44]. As shown in Scheme 6.21, radical reaction of compoimd 92 with BusSnH afforded compound 93 in a 92% yield. 

Metal Complexes of ir-Ligands Containing Organosilicon Groups... 

Organometallic compounds containing both organosilicon groups and transition metal atoms have received much attention in several research laboratories. 

CLASSIFICATION OF tt-LIGANDS TO WHICH ORGANOSILICON GROUPS ARE tr-BONDED... 

PARTICULAR EFFECTS OF THE o-BONDED ORGANOSILICON GROUPS ON THE tt-LIGANDS... 

Migration of organosilicon groups from metal to ligand is believed to be a key step in the mechanism of olefin hydrosilylation catalyzed by nickel-phosphine complexes (59), as shown in Scheme 1. (Substituents are omitted for clarity.)... 

Very few such compounds are known. Three general procedures can be used for their preparation (a) addition of the olefin to a transition metal compound (b) replacement of carbon monoxide in metal carbonyls and (c) migration of organosilicon groups from metal to ligand in some reactions of silylmetal compounds with acetylenes. 

Several attempts to prepare palladium(II)-olefin complexes have failed. Thus, organosilicon groups from /3-trimethylsilylstyrene were cleaved (as chlorotrimethylsilane) by palladium(II) chloride (164) with formation of trans,tran.s-1,4-diphenyl-1,3-butadiene. 

In some early attempts, the formation of i73-allylic complexes containing organosilicon groups was not successful. Thus, the reaction of allyltrimethylsilane with Zeise s salt occurred with olefin exchange to give an -complex, K[Cl3Pt(H2C=CH—CH2SiMe3)] (5i). 

Table 14. Comparison of Inductive and Resonance Constants for Tetra- and Pentacoordinate Organosilicon Groups ...

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