Structural Variances in the Homologous Series of Alkaline Earth Metallated Octamethylcyclotetrasilazandiides

Autor: Lameyer, Lutz, Salah, Omar Abu, Deuerlein, Stephan, Stey, Thomas, Stalke, Dietmar
Zdroj: Zeitschrift für anorganische und allgemeine Chemie; October 2004, Vol. 630 Issue: 12 p1801-1806, 6p
Abstrakt: The magnesium, calcium, and strontium metal derivatives of 2, 2, 4, 4, 6, 6, 8, 8‐octamethylcyclotetrasilazane (OMCTS) have been synthesized and structurally characterized by X‐ray diffraction studies. These are the first complexes of the homologous series of alkaline earth metalated OMCTS. Similar to the homologous series of the corresponding alkali metal complexes, the structural properties show remarkable tendencies in the series from magnesium to strontium. The magnesium dication causes the most pronounced deformation along the transannular N‐···N‐vector of the [(c‐N‐SiMe2‐NH‐SiMe2‐)2]2‐dianionic ring. The lengths of the Si‐N bonds are correlated to the bond types, so that shorter distances result when the bonds become more ionic. The difference between the long Si‐N(H) bonds and the short Si‐N‐bonds decreases gradually with the increasing mass of the alkaline earth metal dication.
Databáze: Supplemental Index