Structure and bonding in hexamethyldisilazane and a series of analogues, (XH3)2YH (X=C, Si, Ge and Y=N, P, As), by ab initio and density functional methods

Theoretical Insights into the Structural Differences between Organic and Inorganic Amines/Ethers

“…In addition, ab intio investigations on (EX 3 ) 2 NH systems (E = Si, Ge) suggest an increased impact of hyperconjugative effects on the structural properties of these species. 48 Owing to these conflicting opinions, further clarifications are required. Herein, we evaluate by means of DFT explorations, the sharp contrast between the geometrical features of organic amines/ethers and their heavier inorganic analogues.…”

“…Inorganic amines reveal particular features as well. Species containing the E 3 N skeleton (E = Si, Ge, Sn) display planar geometries in sharp contrast with the pyramidal structures of organic counterparts, whereas E–N bonds render unusual short distances. − However, compared to the chemistry of inorganic oxanes, theoretical studies − on silylamines are considerably fewer and almost lack heavier analogues containing germanium and tin. Thus, according to computational investigations employing block-localized wave function calculations or based on polarity analyses of the Si–N bonds, the planar geometries of trisilylamine derivatives were explained in terms of electrostatic repulsions between the silyl groups, despite claimed electron paramagnetic resonance evidence for electron donation toward adjacent atoms.…”

“…Thus, according to computational investigations employing block-localized wave function calculations or based on polarity analyses of the Si–N bonds, the planar geometries of trisilylamine derivatives were explained in terms of electrostatic repulsions between the silyl groups, despite claimed electron paramagnetic resonance evidence for electron donation toward adjacent atoms. In addition, ab intio investigations on (EX 3 ) 2 NH systems (E = Si, Ge) suggest an increased impact of hyperconjugative effects on the structural properties of these species . Owing to these conflicting opinions, further clarifications are required.…”