STEREOCHEMISTRY OF 6-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 solut ion of sodium (2R,3R)-(-)-O,O'-dibenzoyltartrate as an eluent. The opt ical isomers were characterized by measurement of their electronic abs orption, circular dichroism, and H-1 NMR spectra. The chromatographic resolution of [Si(bpy)(3)](4+) was also attempted with an aqueous solu tion of potassium [(2R,3R)-(+)-tartrato]antimonate(III), sodium (2R,3R )-(+)-hydrogentartrate, and sodium (2R,3R)-(+)-tartrate as eluents, Fo rce-field calculations were used to elucidate the chromatographic elut ion mechanism. [Si(OH)(2)(bpy)(2)]I-2 was also synthesized from SiI4 a nd 2,2'-bipyridine. The optical resolution of this complex was achieve d with sodium [(2R,3R)-(+)-tartrato]antimonate(III).