Stereoelectronic effects and the problem of the choice of model compounds for organic derivatives of a pentacoordinated silicon atom (taking silatranes as an example)
Vf. Sidorkin et al., Stereoelectronic effects and the problem of the choice of model compounds for organic derivatives of a pentacoordinated silicon atom (taking silatranes as an example), RUSS CHEM B, 48(6), 1999, pp. 1049-1053
Anomeric effects at the silicon atom in silatranes XSi(OCH2CH2)(3)N and mod
el trimethoxysilanes XSi(OMe)(3) (X = H, Me, SiH3, F, Cl) containing a tetr
acoordinated silicon atom were studied by the MNDO and AMI methods. Unlike
silatranes, the nature of substituent X pronouncedly affects the type and d
egree of stereoelectronic effects on the values of X-Si-O-C dihedral angles
, X-Si bond lengths, and proton affinities of trimethoxysilanes. The result
s obtained indicate the necessity of modifying the set of spectral and stru
ctural indications of pentacoordination of the anomeric silicon atom establ
ished previously and observing the principle of conformational similarity f
or compared compounds. Bicyclic organosilicon ethers XSi(OCH2)(3)CH were pr
oposed to be used as models of corresponding silatranes.