Stereochemistry of six-coordinate octahedral silicon(IV) complexes containing 2,2′-bipyridine

[Si(bpy)(3)](4+) (bpy =2,2'-bipyridine), synthesized from SiI4 and 2,2'-bipyridine, was optically resolved by a chromatographic method using an SP-Sephadex C-25 column as an adsorbent and a 0.16 M aqueous solution of sodium (2R,3R)-(-)-O,O'-dibenzoyltartrate as an eluent. The optical isomers were characterized by measurement of their electronic absorption, circular dichroism, and H-1 NMR spectra. The chromatographic resolution of [Si(bpy)(3)](4+) was also attempted with an aqueous solution of potassium [(2R,3R)-(+)-tartrato]antimonate(III), sodium (2R,3R)-(+)-hydrogentartrate, and sodium (2R,3R)-(+)-tartrate as eluents, Force-field calculations were used to elucidate the chromatographic elution mechanism. [Si(OH)(2)(bpy)(2)]I-2 was also synthesized from SiI4 and 2,2'-bipyridine. The optical resolution of this complex was achieved with sodium [(2R,3R)-(+)-tartrato]antimonate(III).