STEREOCHEMISTRY OF SIX-COORDINATE OCTAHEDRAL SILICON(IV) COMPLEXES CONTAINING 2,2-BIPYRIDINE

Abstract

[Si(bpy)₃]⁴⁺ (bpy = 2,2′-bipyridine), synthesized from Sil₄ and 2′.-bipyndine. was optically resolved by a chromatographic method using an SP-Sephadex C-25 column as an adsorbent and a 0.16M 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 ¹H NMR spectra. The chromatographic resolution of [SKbpyb]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]I₂was also synthesized from Sil₄ and 2′,-bipyridine. The optical resolution of this complex was achieved with sodium [(2R,3R)-(+)-tartrato]antimonate(III).