Some Coordination Compounds of Zinc and Silicon

The stmcture of a complex where the central Si atom is bonded covalently to one (amide) N atom and datively to another (pyridine) N atom (D) is shown in Fig. 14. As expected, the datively bonded N atom occupies an axial positimi, and the dative bond is 27 pm longer than the covalent. 

Dimethylaminosilane, H3SiN (013)2, forms nitrogen-bridged pentamers in the solid state (E). The coordination geometries of the Si atoms are distorted trigonal bipyramidal with both axial positions occupied by N atoms. AU Si-N bond distances are equal and must therefore be described as 50% covalent and 50% dative. The Si-N bond distance, 198 pm, is 14 pm longer than the average of the covalent 

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