Synthesis and characterization of a dipyridocatecholate silicon complex

Abstract

The reaction of [Si(bpy) 2 I 2 ]I 2 with 1,10-phenanthroline-5,6-dione followed by metathesis provides various salts of [Si(bpy) 2 (dpcat)] + 2 ( 1 , bpy = 2,2′-bipyridine and dpcat = dipyridocatecholate). Recrystallization of [Si(bpy) 2 (dpcat)](ClO 4 ) 2 from an aqueous solution of NaClO 4 afforded orange crystals of Na[Si(bpy) 2 (dpcatH)](ClO 4 ) 4 ·3H 2 O ( 2 ), in which silicon possesses a distorted octahedral geometry. The dipyridocatecholate ligand is coordinated to the silicon through the oxygen atoms, and one of the nitrogen atoms is protonated. 29 Si NMR and ESI-mass spectroscopy indicate [Si(bpy) 2 (dpcat)] + 2 maintains its hexacoordinate structure in solution. The complex is stable with respect to hydrolysis, and degassed aqueous solutions luminesce at 410 nm. The reaction of [Si(bpy) 2 I 2 ]I 2 with 1,10-phenanthroline-5,6-dione followed by metathesis provides salts of [Si(bpy) 2 (dpcat)] +2 ( 1 , bpy = 2,2′-bipyridine and dpcat = dipyridocatecholate). Recrystallization of [Si(bpy) 2 (dpcat)](ClO 4 ) 2 from an aqueous solution of NaClO 4 afforded orange crystals of Na[Si(bpy) 2 (H-dpcat)](ClO 4 ) 4 ·3H 2 O ( 2 ), in which silicon possessed a distorted octahedral geometry. • The reaction of [Si(bpy) 2 I 2 ]I 2 with 1,10-phenanthroline-5,6-dione generates [Si(bpy) 2 (dpcat)]I 3 I. • The structure of Na[Si(bpy) 2 (H-dpcat)](ClO 4 ) 4 ·3H 2 O was obtained by X-ray crystallography. • Degassed aqueous solutions of [Si(bpy) 2 (dpcat)]Cl 2 luminesce around 410 nm. • Complex is designed to act as a metalloligand.