Heavy Donor Atoms in the Silicon Coordination Sphere

5 Heavy Donor Atoms in the Silicon Coordination Sphere 

A large number of penta- and hexacoordinated silicon compounds are known which comprise hydrogen, 2nd row elements (especially C, N, O, F), and/or chlorine in the silicon coordination sphere (as one can easily conclude from the contents of the previous sections). 

Far less compounds have been reported which comprise heavier elements in the coordination sphere of their penta- or hexacoordinated silicon atom. During the past decade significant contributions emerged on the field of silicon coordinatirai chemistry with heavier lone pair donor atoms, and therefore this section will be dedicated to highlight these compounds. 

As the silicon coordination number can be understood as the number of atoms located in proximity of the Si atom within the sum of the van der Waals radii and a large number of compounds without lone pair dmiation from atoms within this kind of coordination shell would fall into this section (such as those listed in Sect. 5.1), we focus on silicon compounds with five or six formal lone pair donors in the Si coordination sphere (Sects. 5.2-5.T). 

1 Compounds with Si Coordination Number 4 but less than 5 Formal Lone Pair Donors 

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